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IEA-BCS Annex 35: HybVent

4th Expert Meeting

MeetingDocuments

Athen, Greece

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April 11 – 14, 2000

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Contents

Programme.......................................................................3Agenda..............................................................................5Meeting Attendees with addresses.................................6AIVC Workshop on Ventilation Modelling Data Guide.12AIVC Workshop on Occupant Interaction.....................14Programme and Abstracts HybVent Forum ‘00............16Action List 3rd Annex 35 Expert Meeting.......................21Annex 35 Work Groups..................................................23Work Group: A1..............................................................27Work Group: A2..............................................................31Work Group: A3..............................................................38Work Group: A4..............................................................39Work Group: B1..............................................................40Work Group: B2..............................................................41Work Group: B3..............................................................42Work Group: B4..............................................................43Work Group: B5..............................................................61Work Group: B7..............................................................78Work Group: B8..............................................................79Work Group: Final Report..............................................86Pilot Studies....................................................................88Pilot Study Report: Wilkinson......................................89 Pilot Study Report: Tangå School.................................97Pilot Study Report: B&O Headquarters.......................113

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Programme

Tuesday April 11, 20001400 – 1530 AIVC Workshop on Ventilation Modelling Data Guide PH/AIVC

1530 – 1550 Coffee break Hotel

1550 – 1730 AIVC Workshop continued PH/AIVC

Wednesday April 12, 2000900 - 1030 AIVC Workshop on Occupant Interaction WdG/

AIVC


1050 – 1230 AIVC Workshop continued WdG/AIVC

1230 – 1400 Lunch Hotel

1400 – 1530 HybVent Forum on Natural and Hybrid Ventilation OA

1530 – 1600 Coffee Break Hotel

1600 - 1730 HybVent Forum on Natural and Hybrid Ventilation continued OA

2000 Social Dinner ED

Thursday April 13, 20000830 – 0900 Registration

0900 – 1030 Session 1 Agenda 1-4Welcome and introduction to the 4th Expert Meeting, general business, approval of dissemination procedure

OA


1100 – 1230 Session 2 Agenda 5Presentation and approval of State-of-the-art Review.

AD,TAV, OA

1230 – 1400 Lunch Hotel

1400 – 1530 Session 3 Agenda 6.1; 6.6Workgroup meetings

Group Leaders

1530 – 1600 Coffee Break Hotel

1600 – 1730 Session 4 Agenda 6.3; 6.7; 6.9Workgroup meetings

Group Leaders

1730 – 1900 Session 5 Agenda 6.5; 6.10Workgroup meetings

OA

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Friday April 14, 20000830 – 1000 Session 6 Agenda 6.2; 6.4; 6.8

Workgroup meetingsGroup Leaders


1030 – 1230 Session 7 Agenda 7Reports on progess in workgroups

OA

1230 - 1400 Lunch

1400 – 1500 Session 8 Agenda 8Presentation of Pilot Study reports

MC


1530 – 1700 Session 9 Agenda 9, 10 and 11Outline of final report: Principles of Hybrid VentilationSummary of meeting results, general business, conclusions, next meetings and next steps

OA

1700 End of workshop

OA: Per Heiselberg, GG: Gérard Guarracino, YL: Yuguo Li, MC: Marco Citterio, TAV: Tor Arvid Vik, AD: Angelo Delsante, ED: Elena Dascalaki

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Agenda1 Welcome, Introduction.

1.1 Additions to and approval of agenda.1.2 Approval of minutes of 3rd Expert meeting.1.3 Meeting participants and their affiliations.1.4 Goals of this meeting.1.5 Action List from 3rd Expert Meeting

2 Update on Annex 35 confirmed participation, national contact persons, etc.2.1 Annex 35 participants2.2 National contact persons2.3 Work group affiliations

3 Annex 35 Website, presentation of pilot studies, work groups, etc.

4 Dissemination of Annex products

5 Discussion and approval of state-of-the-art review report

6 Workgroup sessions6.1 WG-A1 Characterisation of Ventilation and Control Strategies (SA, DK)6.2 WG-A2 Equivalent Energy Performance Targets in Standards and

Regulations (PW, B)6.3 WG-A3 Comfort Requirements and Energy Targets (WdG, NL)

WG-A4 Application of Analysis Methods in Hybrid Ventilation Design Process (POT, N)

6.4 WG-B1 Incorporation of Thermal Stratification Effects in Network Modelling (YL, AU)

6.5 WG-B2 Methods for Vent Sizing (WdG, NL)6.6 WG-B3 Input Data Bank (MO, UK), WG-B8 Climate Data6.7 WG-B4 Develop Probabilistic Methods (HB, DK)6.8 WG-B5 Wind Flows through Large Openings (MS, S)6.9 WG-B7 Integrate or Implement Control Strategies into Models6.10 WG Outline of “Principles of Hybrid Ventilation”

7 Reports on progress in workgroups

8 Presentation of first draft of Pilot Study Reports

9 Outline of “Principles of Hybrid Ventilation”

10 Future expert meetings10.1 5th expert meeting in Brussels, Belgium, October 2-5, 200010.2 6th expert meeting in The Netherlands, April/May, 200110.3 7th expert meeting in Changcha, China, October, 2001

11 Summary of workshop results, action list, next steps, and conclusions.

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Meeting Attendees with addresses

Søren Aggerholm (SA), Danish Building Research Institute, Denmark

Åke Blomsterberg (AB), J&W Consulting Engineers

Henrik Brohus (HB), Aalborg University, Denmark

Tomoyuki Chikamoto (TC), Nikken Sekkei Ltd, Japan

Marco Citterio (MC), ENEA, ERG SIRE C.R. Casaccia, Italy

Florence Cron (FC), Université de la Rochelle, LEPTAB, France

Elena Dascalaki (ED), University of Athens, Greece

Willem de Gids (WG), TNO Building & Constr. Research, The Netherlands

Angelo Delsante (AD), CSIRO Building, Construction and Engineering, Australia

Gian Vincenzo Fracastoro (GF), Politecnico di Torino, Dept. di Energetica, Italy

Roger Grundmann (RG), Technische Universität Dresden, Germany

Gérard Guarracino (GG), ENTPE, Lyon, France

Fariborz Haghighat (FH), Concordia University, Canada

Nicolas Heijmans (NH), BBRI, Belgian Building Research Institute, Belgium

Jorma Heikkinen (JH), VTT Building Technology, Finland

Per Kvols Heiselberg (PH), Indoor Environmental Engineering, Aalborg University, Denmark

Ole Juhl Hendriksen (OH), Esbensen Consulting Engineers, Denmark

Yuguo Li (YL), CSIRO Building Construction and Engineering, Australia

David M. Lorenzetti (DL), Lawrence Berkeley Laboratory, USA

Malcolm Orme (MO), Air Infiltration and Ventilation Centre (AIVC), United Kingdom

Markus Rössler (MR), Technische Universität Dresden, Germany

Matheos Santamouris (MS), University of Athens, Greece

Peter Schild (PS), Norwegian Building Research Institute, Norway

Per Olaf Tjelflaat (POT), Norwegian University of Science & Technology, Norway

Ad van der Aa (AA), Cauberg-Huygen Raadgevende Ingenieurs B.V., The Netherlands

Åsa Wahlström, (AW), Swedish National Testing and Research Institute, Sweden

Peter Wouters (PW), BBRI, Belgian Building Research Institute, Belgium

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Søren AggerholmDanish Building Research InstituteDr. Neergaardsvej 15Postboks 119DK-2970 HørsholmDenmarkTelephone: + 45 4586 5533, Fax: + 45 4586 7535, E-mail: [email protected]

Åke BlomsterbergJ&W Consulting EngineersSlagthusetS-21120 MalmöSwedenTelephone: + 46 40 108 266, Fax: + 46 40 108 201, E-mail: [email protected]

Henrik BrohusIndoor Environmental EngineeringAalborg UniversitySohngårdsholmsvej 57DK-9000 AalborgDenmarkTelephone: + 45 9635 8539, Fax: + 45 9814 8243, E-mail: [email protected]

Tomoyuki ChikamotoNikken Sekkei Ltd., Environmental Engineering Group2-1-2 Koraku, Bunkyo-kuTokyo 112-8565JapanTelephone: + 81 03 3813 3361, Fax: + 81 03 3818 8238, E-mail: [email protected]

Marco CitterioENEA SIRE HABC.R. Casaccia, Via Anguillarese 301S. Maria di Galeria, I-00060 RomaItalyTelephone: + 39 06 3048 3703, Fax: + 39 06 3048 6315, E-mail: [email protected]

Florence CronLEPTAB Université de La RochellePôle Sciences et TechnologieAv. Michel CrépeauF-17042 La RochelleFranceTelephone: + 33 5 46 45 86 22, Fax: + 33 5 46 45 82 41, E-mail: [email protected]

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mailto:[email protected]







Elena DascalakiUniversity of Athens, Department of Applied PhysicsUniversity Campus, Build. Phys. - VGR 157 84 - AthensGreeceTelephone: + 301 7276841, Fax: + 301 7295282, E-mail: [email protected]

Willem de GidsTNO Building & Constr. ResearchDept. of Indoor Environ., Buildg. Physics and InstallationsPostbus 49NL-2600 AA DelftThe NetherlandsTelephone: + 31 15 269 5280, Fax: + 31 15 269 5299, E-mail: [email protected]

Angelo DelsanteCSIRO Building, Construction and EngineeringP.O. Box 563190 Highett, VicAustraliaTelephone: + 61 3 9252 6056, Fax: + 61 3 9252 6251, E-mail: [email protected]

Gian Vincenzo FracastoroPolitecnico di TorinoDept. di EnergeticaCorso Duca degli Abruzzi, 24I-10129 TorinoItalyTelephone: + 39 011 564 4438, Fax: + 39 011 564 4499, E-mail: [email protected]

Roger GrundmannTechnische Universität DresdenInstitut für Luft- und RaumfahrttechnikMommsenstr. 13D-01062 DresdenGermanyTelephone: + 49 351 8086, Fax: + 49 351 8087, E-mail: [email protected]

Gérard GuarracinoENTPE / DGCB / LASH -URA CNRS 1652Rue Maurice AudinF-69518 Vaulx-en-Velin CédexFranceTelephone: + 33 (0) 4 72 04 70 31, Fax: + 33 (0) 4 72 04 70 41, E-mail: [email protected] Haghighat

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Concordia UniversityDept. of Building, Civil and Environ. Eng.1455 de Maisonneuve Blvd. WestMontreal, Quebec, H3G 1M8CanadaTelephone: + 1 514 848 3192, Fax: + 1 514 848 7965, E-mail: [email protected]

Nicolas HeijmansBBRI-WTCB-CSTCrue de la Violette 21-231000 BrusselsBelgiumTelephone: + 32 2 655 77 11, Fax: + 32 2 653 07 29, E-mail: nicolas.heijmans@bbri-be

Jorma HeikkinenVTT Building TechnologyLämpömiehenkuja 3, EspooP.O. Box 1804FIN-02044 VTTFinlandTelephone: + 358 9 456 4742, Fax: + 358 9 455 2408, E-mail: [email protected]

Per Kvols HeiselbergIndoor Environmental EngineeringAalborg UniversitySohngårdsholmsvej 57DK-9000 AalborgDenmarkTelephone: + 45 9635 8541, Fax: + 45 9814 8243, E-mail: [email protected]

Ole Juhl HendriksenEsbensen Consulting EngineersVesterbrogade 124 BDK-1620 Copenhagen VDenmarkTelephone: + 45 3326 7300, Fax: + 45 3326 7301, E-mail: [email protected]

Yuguo LiCSIRO Building Construction and EngineeringGraham RoadPO Box 56Victoria 3172, HighettAustraliaTelephone: + 61 3 9252 6175, Fax: + 61 3 9252 6251, E-mail: [email protected]

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mailto:nicolas.heijmans@bbri-be




David M. LorenzettiLawrence Berkeley National Lab.1 Cyclotron RoadMail Stop 90-305894720 Berkeley CAUSATel: + 1 (510) 486-4562, Fax: + 1 (510) 486 6658, E-mail: [email protected]

Malcolm OrmeAir Infiltration and Ventilation Centre (AIVC)University of Warwick Science ParkUnit 3A, Sovereign Court, Sir William Lyons RoadCoventry CV4 7EZUnited KingdomTelephone: + 44 24 7669 2050, Fax: + 44 24 7641 6306, E-mail: [email protected]

Markus RöslerTechnische Universität DresdenInst. für Thermodynamik und Technische GebäudeausrüstungMommsenstrasse 13D-01062 DresdenGermanyTelephone: + 49 351 4802, Fax: + 49 351 7105, E-mail: [email protected]

Matheos SantamourisUniversity of AthensDept. of Applied PhysicsUniversity CampusGR-157 84 AthensGreeceTelephone: + 301 7276847, Fax: + 301 7295282, E-mail: [email protected]

Peter G. SchildNorwegian Building Research InstituteP.O. Box 123 BlindernN-0314 OsloNorwayTel: + 47 22 96 58 54, Fax: + 47 22 96 57 25, E-mail: [email protected]

Per Olaf TjelflaatNorwegian University of Science & Technology, - NTNUDepartment of Refrigeration and Air ConditioningN-7491 TrondheimNorwayTelephone: + 47 73 593 864, Fax: + 47 73 593 859, E-mail: [email protected]/[email protected] van der Aa

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mailto:[email protected]/[email protected]








Cauberg-Huygen Raadgevende IngenieursBoterdiep 48Postbus 92223007 AE RotterdamThe NetherlandsTelephone: + 31 10 4257444, Fax: + 31 10 4254443, E-mail: [email protected]

Åsa WahlströmSwedish National Testing and Research InstituteEnergy Technology, System & Ventilation TechnologyBox 857SE-50115 BoråsSwedenTelephone: + 46 33 165589, Fax: + 46 33 131979, E-mail: [email protected]

Peter WoutersBBRI, Belgian Building Research InstituteRue de la Violette 21-23B-1000 BrusselsBelgiumTelephone: + 32 2 655 77 11, Fax: + 32 2 653 0729, E-mail: [email protected]

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AIVC Workshop - Ventilation Modelling Data GuideProvisional Programme

Tuesday 11th April, 2000

Astir Palace Hotel, Vouliagmeni, Athens, Greece

Chairman: Per Heiselberg, Aalborg University, Denmark

14.00 - 14.15 Introduction

Malcolm Orme, AIVC, Current state-of-the-art of the Data Guide

14.15 - 14.45 Presentations of some ideas

Willem de Gids (TNO, The Netherlands)

”eVent - AIVC Numerical Data Guide and Annex 35?” by Yuguo Li (CSIRO, Australia)

”Wind speed in the Urban Environment” by Mat Santamouris (University of Athens, Greece).

14.45 - 15.00 Definition of topics to be discussed in the parallel sessions

15.00 - 16.30 Parallel workshop sessions:- current structure and future developments,- input data,- model evaluation data.

(with coffee break 15.30 - 15.50)

16.30 - 17.00 Presentation of results

17.00 - 17.30 Chairman's summary, discussions and conclusions

One task in the current work programme of the AIVC is identify and collate applicable default input data and algorithms suitable for ventilation and air infiltration modelling in an electronic Data Guide. Previously, organisations in many countries have contributed data to establish a unique collection of numerical data suitable for design purposes and model evaluation. By combining information from these multiple sources, it is possible to consider a far wider range of operating conditions than would be possible by using the results from a single set of measurements alone. The existing data collection covers component leakage, whole building leakage, wind pressure coefficients and measurement results for model evaluation. The aim of this Workshop is to provide a strategic overview of how the AIVC Ventilation Modelling Data Guide should develop. The discussion is likely to include:

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structure of the Data Guide,

building and terrain related input data,

- airtightness data,

- wind surface pressure coefficient data,

ventilation provisions,

meteorological data,

occupant related data,

pollutant modelling data, and

model evaluation data.

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AIVC Workshop - Occupant Interaction on VentilationProvisional Programme

Wednesday 12th April, 2000

Astir Palace Hotel, Vouliagmeni, Athens, Greece

Martin W. Liddament

The objective of this workshop is to summarise the draft AIVC report on Occupant Impact on Ventilation and to develop specific input.

The proposed programme is:

09.00 Chairman's introduction and outline of workshop structure.

Willem de Gids

09.20 AIVC report 'Occupant Impact on Ventilation'.

Martin Liddament

09.50 Parallel workshop sessions (45 minutes)

1. Identifying responsibilities,

2. Identifying occupant needs,

3. Innovative controls and strategies,

4. Algorithms - modelling occupant behaviour patterns.

(10.40 - 11.00 Coffee break)

11.00 Workshop Chairman's report

12.00 - 12.30 Conclusions

Workshop Session Themes - Additional Details

1. Identifying Responsibilities

The intention of this session is to determine those areas which are (a) beyond and (b) within the control of occupants. A series of practical recommendations is then needed, aimed at improving the ability of the occupant to achieve a satisfactory indoor environment. Suggested areas include:

- The role/need for legislation/standards;

- Design/construction;

- Other players;

- The occupant.

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2. Identifying Occupant Needs

This session should focus on the climatic needs of occupants (i.e. indoor air quality and thermal comfort). Key aspects include:

- Identification of parameters;

- How needs should be met;

- Requirements according to building type (dwellings, non-residential buildings etc.);

- How these needs can be met.

The outcome should include a key list of elements identifying major issues and solutions. This could be presented as a matrix of parameters vs. specific building types/uses.

3. Innovative Controls and Strategies

An important area for occupant impact development is in relation to controls and ventilation strategies. Aspects cover the identification of approaches according to:

- Building type;

- Pollutants;

- Systems (type, reliability, ease of use and, effectiveness etc.)

Outcome should include recommendations and new ideas for ventilation control methods.

4. Algorithms - modelling occupant behaviour patterns

This session is aimed at identifying methods of simulating occupant activities. Areas include:

- Existing algorithms;

- Items that should be incorporated into simulation methods.

Outcome should include a summary of the relevant components that need to be considered in occupant simulation.

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Programme HybVent Forum ’00Athen, Greece, April 12, 2000

1400 – 1530 Session AHybrid Ventilation Expectations among Finnish Designers and Decision Makers.Jorma Heikkinen and Ismo Heimonen, VTT, Finland.

Hybrid Ventilation Concepts in Commercial Buildings - Indoor Air Quality and Energy Economy Perspective.Jarmo Heinonen, Olof Granlund Oy, and Risto Kosonen, Oy Halton Group Ltd, Finland.

Application of EP approach on Dutch School Building – Impact of Varying Boundary Conditions.Ad van der Aa, Cauberg-Huygen Raadg. Ing. B.V., The Netherlands.

Preliminary Results of BEMS-monitoring at Bang & Olufsen Office Building.Ole Juhl Hendriksen, Esbensen Consulting Engineers, Denmark.

Preliminary Results from Detailed Measurements at Bang & Olufsen Headquarters.Henrik Brohus, Christian Frier and Per Heiselberg, Aalborg University, Denmark

1530 – 1600 Coffee Break1600 – 1730 Session B

Study of a Solar Chimney Natural Ventilation System.Yuguo Li, CSIRO, Australia, and Fariborz Haghighat, Concordia University, Canada.

Effect of Thermal Stratification on Heat Flows in Large EnclosuresFlorence Cron, Laurent Mora and Christian Inard, Université de la Rochelle, France.

Stochastic Input Loads.Henrik Brohus, Aalborg University, Denmark, Fariborz Haghighat, Concordia University, Canada, Christian Frier and Per Heiselberg, Aalborg University, Denmark.

Impact of the Uncertainty of Wind Pressures in the Prediction of Indoor Air Quality and Thermal Comfort Levels.Nicolas Heijmans, BBRI, Belgium

Solution Multiplicity in Wind Opposed Natural Ventilation – We proved it!Yuguo Li, CSIRO, Australia, and Per Heiselberg, Aalborg University, Denmark.

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Abstracts HYbVent Forum ’00Athen, Greece, April 12, 2000

Hybrid Ventilation Expectations among Finnish Designers and Decision Makers.Jorma Heikkinen and Ismo Heimonen, VTT, Finland.

An interview survey was carried out among Finnish leading designers and decision makers on the expectations and barriers of the use of hybrid ventilation in office and educational buildings. The purpose was to support the technical part of the project where new ventilation systems will be created and evaluated. To be able to compare with the other European countries the questionnaire was taken from the European NatVent project.The results show that an increase in the use of natural forces in ventilation of buildings is expected. The hybrid ventilation can be well accepted by the users because of low noise level, feeling of natural ventilation and the possibility of user interaction. It is expected thathybrid ventilation is especially attractive in combination with daylighting, atriums and double facades. It is also believed that the main problems like preheating of the supply air, filtering as well as problems with heat recovery can be technically solved with satisfaction. The building regulations were not regarded to be a major barrier for theacceptance of hybrid ventilation.

Hybrid Ventilation Concepts in Commercial Buildings - Indoor Air Quality and Energy Economy Perspective.Jarmo Heinonen, Olof Granlund Oy, and Risto Kosonen, Oy Halton Group Ltd, Finland.

Hybrid ventilation concepts for commercial buildings are presented in this paper. Concepts are specially designed for northern climate conditions. Probably the most potential concept will be a combination of all these concepts, because hybrid systems are always more or less dependent on structure of buildings. The bases of the concepts are efficient and demand based use of low pressure fans. The concepts are equipped with IR- and CO2-sensors to guarantee the efficient usage of energy. The concepts have been carried out with individual control of indoor air temperature, so they fit well both to open-plan and cellular office types, and make the flexibility possible. The key of the concepts is intelligent automationsystem.

Application of EP approach on Dutch School Building – Impact of Varying Boundary Conditions.Ad van der Aa, Cauberg-Huygen Raadg. Ing. B.V., The Netherlands.

Preliminary Results of BEMS-monitoring at Bang & Olufsen Office Building.Ole Juhl Hendriksen, Esbensen Consulting Engineers, Denmark.

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The monitoring programme was initiated at February 2000 and the first results from the BEMS-system are now available. The purpose of the monitoring programme is to analyse the hybrid ventilation system of the building regarding performance of indoor climate and energy consumption. The results will be used to test and demonstrate new calculation models and to evaluate indoor climate and energy consumption. The monitoring programme combines short-term measurements using portable equipment and long-term measurements with the BEMS-system of the building. This presentation will only deal with long-term measurements for a period of approximately one month at winter conditions. In this period the hybrid ventilation system was running in CO2 mode, but with major periods where the system was shut-off due to low outdoor temperatures (<5ºC) in daytime. The weather has been both clear and cloudy with some periods of strong winds and with moderate temperatures.

The presentation will focus on indoor climate conditions such as room temperatures, inlet temperatures, exhaust temperatures and CO2 concentrations. Data has in general been logged every 15 minutes, but the data has been logged every 30 seconds for a period of one week, which are suitable for analysis of the most dynamic parameters. Furthermore, practical experiences with the implemented control strategy and some suggestions to adjust set values for the hybrid ventilation system will be presented and discussed. Energy consumption will not be presented, because sufficient data are not available at the moment.

An analysis of preliminary results from the first month of monitoring shows, that it is necessary to use the ribbed heat pipes for heating at the glazed facade to prevent cold draught. Comparable values of the logged CO2 concentrations shows large variations at one floor, which indicates some uncertainties for the CO2 sensors.

Preliminary Results from Detailed Measurements at Bang & Olufsen Headquarters.Henrik Brohus, Christian Frier and Per Heiselberg, Aalborg University, Denmark

As part of the measurement programme concerning the B&O headquarter in Denmark, three periods of detailed measurements will be conducted on site. The measurements comprise 1) A period of “cold winter”, where the building envelope of the hybrid ventilated building is kept closed and poor IAQ might be expected. 2) A “warm summer” period, where overheating might be expected. 3) An “intermediate period” where the ventilation principle and control strategy are assumed to work optimally.

Preliminary results from the “cold winter” measurement period are presented. The results comprise detailed temperature fields (time series) in selected parts of the building, CO2 monitoring including vertical and horizontal distributions, various tracer gas measurements examining the ventilation effectiveness, and indoor climate measurements.

Study of a Solar Chimney Natural Ventilation System.Yuguo Li, CSIRO, Australia, and Fariborz Haghighat, Concordia University, Canada.

We present here a solar chimney experiment carried out at CSIRO by a Cocordia University student using a small-scale model with a recently developed fine bubble technique. Parameters studied in the experiments are the cavity width of the solar

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chimney, the solar radiation intensity, the height of the solar chimney, the room inlet area and the solar chimney inlet area. Results showed that for given building geometry and inlet areas, there is an optimum cavity width at which a maximum ventilation flow rate can be achieved. This optimum cavity width, which is independent of the solar radiation intensity, was found to be dependent on the chimney height, the size of the room inlet and the size of the solar chimney inlet. Comparisons between the measured ventilation flow rate and predictions by a simple theoretical analysis presented suggested that theoretical models, which assume uniform temperature distribution across the chimney width, may overpredict the chimney performance at some situations and should be used with care.

Effect of Thermal Stratification on Heat Flows in Large EnclosuresFlorence Cron, Laurent Mora and Christian Inard, Université de la Rochelle, France.

In the framework of the Annex 35 Subtask B, we need to predict air flows between different zones of a whole building, in order to evaluate the hybrid ventilation system effectiveness. Thus we have to take into account the thermal behaviour and distribution in each zone to know the detailed air and heat flows. We decided to use zonal models in an object oriented environment, SPARK. SPARK’s interest consists in his solver and the duplication of mass and heat balance equations for each zone. We can also integrate specific air flow models and use a heat transfer model through the building envelope.

We started this study with the simulation of a three-storey building, with an office on each storey and a large hall or staircase. This case doesn’t take into account conduction through walls, neither radiation. We realize here a comparison between the multizone approach, where the heat sources are homogeneous in several cells, and the zonal approach with a thermal plume model induced by a convector. The results let us compare the effects of thermal stratification and heat flows in a large enclosure for a given heat power and with or without dominating flows.

Stochastic Input Loads.Henrik Brohus, Aalborg University, Denmark, Fariborz Haghighat, Concordia University, Canada, Christian Frier and Per Heiselberg, Aalborg University, Denmark.

In order to quantify uncertainty in thermal building simulation stochastic modelling is applied on a building model. This part of the work deals with the determination of the corresponding stochastic input loads. The importance of obtaining a proper statistical description of the input quantities to a stochastic model is addressed and exemplified by stochastic models for the external air temperature and the solar heat gain.

Each of the external climate parameters is modelled as a stochastic process with time varying mean value function superimposed by a time varying standard deviation function. The statistics of the external air temperature is obtained by means of Fast Fourier Transform (FFT). A model of the solar heat gain is presented, considering the obvious fact that solar radiation is present only during daytime. The Danish Design Reference Year (DRY) is used as experimental data.

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Impact of the Uncertainty of Wind Pressures in the Prediction of Indoor Air Quality and Thermal Comfort Levels.Nicolas Heijmans, BBRI, Belgium

Solution Multiplicity in Wind Opposed Natural Ventilation – We proved it!Yuguo Li, CSIRO, Australia, and Per Heiselberg, Aalborg University, Denmark.

Our previous presentations showed that under certain conditions, multiple solutions for the flow rate exist in a natural ventilation system, induced by the non-linear interaction between buoyancy and wind forces. Under certain physical simplifications, the system is governed in steady state by a non-linear algebraic equation or a system of equations. This presentation showed a recent experiment carried out at CSIRO by two Aalborg University students, using a small-scale water model in a water tunnel. The new experiments confirm that two steady-state solutions exist for a single-zone building. These results have significant implications for multi-zone modelling of natural ventilation and smoke spread in buildings.

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Action list 3rd Annex 35 Expert MeetingState-of-the-art Report

Send ½-page describing HybVent performance expectations to AD and TAV by October 15, 1999 All

Building survey co-ordinators to provide remaining information to AD, chapter 2 by October 15, 1999 Co-ordinators

Detailed building survey data on 11 buildings to OJH, by November 1, 1999 PP, PS, POT, ÅB, JP

Data on standards and regulations survey to TAV by October 15, 1999 JP

1-page introduction to chapter 4 to PM by October 15, 1999 PW

Inclusion of 2-page summary results in chapter 4 by November 15, 1999 PM

General information to be included in the report to be send to editors by October 15, 1999 OA

Report to participants for final comments by December 1, 1999 Editors

Comments on report to editors by December 15, 1999 All

Report to ExCo reviewers by January 1, 2000 Editors

Work Groups Work Group Co-ordinators sends revised description and 1-page

summary of meeting results to OA before Nov 1, 1999 WGC

Work Group actions in attachment 5 and 6 All

Web-site Discussion boards to be changed and established a.s.a.p. OA

Forum papers published a.s.a.p. OA

Send bibliographic information on published Annex 35 work to OA to be included in the record of publications All

Send technical papers and/or working documents to be published on the Web to OA All

Pilot studies to be presented a.s.a.p. OA

Send link to national projects to OA All

Send description of subtask work to OA a.s.a.p SL’s

Miscellaneous Approach ExCo members for formal annex commitment a.s.a.p. B, D, N, S, UK,

US

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Form/format for Pilot Study Report send to Pilot Study Co-ordinators (PSC) by November 1, 1999 MC

First Draft of pilot study report to participants by March 1, 2000 PSC

Preliminary measurement results to MO before next meeting in Greece

B (PW), DK (OJH), N (POT) Make local arrangements for 4th expert meeting in Greece ED Send invitation and prepare program for 4th Expert meeting OA Preliminary preparations for 5th Expert meeting in Belgium PW Note future meetings All

Preparations by Participants All: Complete meeting registration and return to OA by

March 17, 2000

All: Hotel reservation for the hotels on the list (reservation are to be made directly to the travel agent Mrs M. KOUZINOU) A.S.A.P.

All: If you have a technical presentation for the HybVent Forum prepare a short presentation and send an abstract to the OA by March 17, 2000

Editors: Draft of state-of-the-art Review to be sent to participants A.S.A.P.

All: Go through the Action List of the 3rd Expert Meeting A.S.A.P.

Pilot Study Coordinators: Send draft of Pilot Study Reports to MC, and to OA for inclusion in meeting documents March 31, 2000

Pilot Study Coordinators: Send preliminary measurement result from Pilot Studies to MC March 31, 2000

Work Group Leaders: Send progress reports on work groups to OA March 31, 2000

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Annex 35 Work Groups WG-A1 Characterisation of Ventilation and Control Strategies.Co-ordinator: Søren Aggerholm

SA Søren AggerholmMC Marco CitterioWG Willem de GidsGG Gerard GuarracinoJOH Jorma HeikkinenPH Per HeiselbergOJH Ole Juhl HendriksenPM Pierre MichelJP John PalmerPP Paolo PrincipiER Elena RuffiniPOT Per Olaf TjelflaatPW Peter WoutersTAV Tor Arvid Vik

WG-A2 Equivalent Energy Performance Targets in Standards and Regulations.Co-ordinator: Peter Wouters

SA Søren AggerholmAA Ad van der AaWG Willem de GidsGG Gerard GuarracinoJK Jarek KurnitskiPW Peter WoutersTAV Tor Arvid Vik

WG-A3 Comfort Requirements and Energy Targets.Co-ordinator: Willem de Gids

MC Marco CitterioWG Willem de GidsJH Jorma HeikkinenPH Per HeiselbergOJH Ole Juhl HendriksenYL Yuguo LiPM Pierre MichelJP John PalmerPP Paolo PrincipiER Elena RuffiniPS Peter SchildPOT Per Olaf TjelflaatTAV Tor Arvid Vik

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WG-A4 Application of Analysis Methods in the Hybrid Ventilation Design Process.Co-ordinator: Per Olaf Tjelflaat

MC Marco CitterioWG Willem de GidsJH Jorma HeikkinenPH Per HeiselbergOJH Ole Juhl HendriksenYL Yuguo LiPM Pierre MichelJP John PalmerPP Paolo PrincipiER Elena RuffiniPS Peter SchildPOT Per Olaf TjelflaatTAV Tor Arvid Vik

WG- B1 Incorporate Thermal Stratification Effects in Network ModellingCo-ordinator: Yuguo Li

HB Henrik BrohusTC Tomoyuki ChikamotoAD Angelo DelsanteTHD Tor Helge DokkaFH Fariborz HaghighatCI Christian InardYL Yuguo LiMP Marco Perino

WG-B2 Methods for Vent SizingCo-ordinator: Willem de Gids

KTA Karl Terpager AndersenWG Willem de GidsFH Fariborz HaghighatYL Yuguo LiMP Marco PerinoSR Svein H. RuudPT Paolo TronvillePW Peter Wouters

WG-B3 Input Data BankCo-ordinator: Malcolm Orme

ED Elena DascalakiMO Malcolm OrmeSR Svein H Ruud

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WG-B4 Development of Probabilistic MethodsCo-ordinator: Henrik Brohus

HB Henrik BrohusTC Tomoyuki ChikamotoGF Gian Vincenzo FracastoroFH Fariborz HaghighatYL Yuguo LiMO Malcolm OrmeMP Marco Perino

WG-B5 Wind Flows through Large OpeningsCo-ordinator: Mats Sandberg

KTA Kar Terpager AndersenGM Gerard GuarracinoFH Fariborz HaghighatYL Yuguo LiMP Marco PerinoMS Mats Sandberg

WG-B6 Evaluation of Analysis Tools – Specification of Data RequirementCo-ordinator: Yuguo Li

MC Marco CitterioTHD Tor Helge DokkaFH Fariborz HaghighatJOH Jorma HeikkinenYL Yuguo LiMO Malcolm OrmeMR Markus RoslerPT Paolo Tronville

WG-B7 Integrate or Implement Control Strategies into ModelsCo-ordinator: ?

ED Elena DascalakiAD Angelo DelsanteWG Willem de GidsCI Christian InardJK Jarek KurnitskiPM Pierre MichelJP John PalmerSR Svein H RuudBS Brian Smith

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WG-B8 Climate DataCo-ordinator: Gian Vincenco Fracastoro

AA Ad van der AaED Elena DascalakiMC Marco CitterioGF Gian Vincenzo FracastoroMO Malcolm OrmePW Peter Wouters

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Work Group A1Characterisation of Hybrid Ventilation and Control StrategiesAction List

B&O example from co-ordinator, end Oct. 1999 (delayed one month)

One full example and 2-3 brief examples from each participant (country), end Feb. 2000.

Presentations at next meeting

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Example of hybrid ventilation and control strategy: B&O Headquarter, StruerSøren Aggerholm, SBISketch of ventilation principle

NS

Building size and site approx. 1650 m2

approx. 80 persons (work desks) Open area No external pollution No external noise

General building lay-out Three storey Limited building depth Open plan offices No meeting rooms (Office wing, part of three wing building complex)

Design aim Maximal use of natural ventilation (architect)

Ventilation principle Natural ventilation with fan assistance

Control principle Central control Limited user control

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Ventilation strategy Inlets distributed along facade at each floor Preheating Displacement ventilation Open floor plan Open between floors Central extract over roof Stack and wind driven Fan assistance if needed Additional ventilation by opening windows Heavy building

Control strategyWinter: Time table or occupancy (choose by operator) IAQ or constant ventilation (choose by operator) Fully automatic Constant supply temperature Same air flow through all inlets Inlets and extract closed at low temperature or high wind speed User control of windows Windows closed at high wind speedSummer: Centrally controlled night cooling

Ventilation solution The inlets in the north facade are low positioned, narrow hatches in front of the

floor slap, designed as ordinary windows. There are 6 inlet section per floor. The inlet air is preheated with a ribbed heating pipe covered in the floor slap. Each floor is one large office without partition walls. There are open between the floors through the two stairways. The extract hoods are positioned on top of the stairways. The ventilation is mainly driven by the stack effect and the under pressure at roof

level from wind. The natural driving forces are supported by a low pressure fan in the extract hood

when needed. The extract hood also includes a shut-off damper in front of the fan ? and bypass

dampers on the sides of the fan to reduce the pressure drop when the fan is not operating.

The design air exchange rate is 1.5 ach. during winter and 3.0 ach. during summer. Additional ventilation can be achieved by the occupants by opening the small, high

positioned ventilation windows in the south facade or by opening the ordinary windows in the same facade.

The slaps, the inner leaf of the external walls and the walls around the stairways are made of concrete.

The ceilings are free from false ceiling and acoustic regulations.

Control implementation

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There are two CO2-sensors and room temperature sensors on each floor. There is an air speed sensor in front of each extract hood. There is an inlet temperature sensor in each inlet section External temperature, wind speed and wind direction is measured on top of the

building by the BMS. Rain fall is also detected. There are two different possibilities to distinguish between occupancy hours and

none occupancy hours:- According to time table of normal office hours- Based on signal from the entrance control systemThe selection of mode is done by the operators in the building.

There are also two different control modes during occupancy hours:- CO2-control with constant set point- Constant air exchange rateThe selection of control mode is done by the operators in the building.

The inlet hatches and the extract dampers are adjusted to achieve the necessary air flow. The primary control is by the hatches.

The inlet hatches is controlled individual per floor if CO2-control. The inlet hatches is controlled together for the building if constant air exchange

rate. The opening of the individual inlet hatch is adjusted based on the signal to the valve

controlling the ribbed heating pipe to have the same opening of all valves and hence have the same airflow through all inlet hatches.

If the inlet temperature drops below the set point the opening of the inlet hatches is reduced.

The fan in the extract hood is controlled in cascade with the extract dampers. The ventilation windows in the south facade is equipped with motors. The ordinary windows are manually operated. All windows are controlled by the occupants. Night cooling by ventilation is activated if the room temperature during none

occupied hours is over ? oC. During night cooling both the inlet hatches, the windows in the south facade and the dampers in the extract hood are fully open. The fan ?

The inlet hatches are closed if the wind speed is over x ? m/s and the wind direction is east or west. The dampers in the extract hood is also closed if the wind speed is over y ? m/s.

The inlet hatches and extract dampers are also closed if the external temperature is below 0 oC.

If rain is falling and the wind speed is higher than z ? m/s both the inlet hatches, the extract dampers and the ventilation windows in the south facade are closed.

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Work Group A2Equivalent energy performance targets in standards and regulationsAction List

1-day meeting on January 25 2000 meeting in Brussels

An overview of the approach used or under development in the Netherlands, France, Denmark and Belgium will be prepared for this meeting

A sensitivity analysis of impact of the boundary conditions on the EP level will be prepared for a Dutch school building

A preliminary agenda is given in table 1Time Topic Prepared by :

9.00 Introduction & general issues P. Wouters

9.20 Dutch approach : specific information concerning A2 W.F. De Gids

9.40 BE approach P. Wouters

10.00 French standard G. Guarracino

10.20 DK information S. Aggerholm

10.40 Discussion and some preliminary conclusions

11.30 Application of EP approach on Dutch school building : impact of varying boundary conditions

A. Van der Aa

12.30 Lunch

13.30 To be agreed later on or during the meeting

table 1 : Draft agenda for Brussels meeting January 25 2000

For the Athens meeting, the following outcome is expected :

First draft report of existing procedures in EP standards and regulations

First draft report of inventory of existing application(s) of EP approach on hybrid concept

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WG A2 Equivalent Energy Performance Targets in Standards and Regulations

Meeting minutesBrussels, the 25th of January 2000

Peter Wouters, Nicolas Heijmans

Division of Building Physics and Indoor Climate

Belgian Building Research InstituteCSTC - WTCB25 January 2000

Table of contents1. Introduction 33

1.1 Meeting attendees 331.2 Agenda of the meeting Fejl! Bogmærke er ikke defineret.

2. Summary of the presentations and discussions 34

2.1 Introduction & general issues 342.2 Dutch approach 342.3 Belgian approach 342.4 French approach 352.5 Danish approach 352.6 Application of EP approach on Dutch school building : impact of varying boundary conditions

352.7 General discussion 352.8 Work to be done for the Athens meeting 36

3. Action list 36

Annexes 36

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1. IntroductionAs agreed during the 3rd Expert Meeting in Sydney, a one-day meeting was held in Belgium on the 25th of January 2000. An overview of the approach used or under development in the Netherlands, France, Denmark and Belgium was presented at this meeting. A sensitivity analysis of impact of the boundary conditions on the EP level was prepared for a Dutch school building.

The EP regulations consider the total primary energy consumption as criteria and fix a maximal value that can not be exceeded. In some countries, those regulations replace older ones that were only partly dealing with the building’s energy load, like the insulation level for instance. The EP regulations take also into account the ventilation, the internal gains, the solar gains, etc…

The calculated EP is not supposed to reflect completely the real energy consumption, even if it would be the ideal situation. It is a reference consumption. EP regulations are only tools to limit the consumption of a building (in order to limit the CO2 production of the residential and non-residential sectors), while ensuring a good indoor climate.

The EP determination method can not handle all the existing systems and concepts, and can certainly not handle the new ones. Those systems/concepts must be estimated by an other way that the standard procedure. Specifics studies have to be down to prove the equivalence of those systems/concepts, according to the equivalence principle.

1.1 Meeting attendees and agendaBelgium : P. Wouters, N. Heijmans, D. Van OrshovenDenmark : S. AggerholmFrance : G. GuarracinoNetherlands : A. Van der Aa, W. De Gids

Time Topic Prepared by 09.50 Introduction & general issues P. Wouters

10.00 Dutch approach : specific information concerning A2 W.F. De Gids

10.50 Belgian approach P. Wouters

11.35 French standard G. Guarracino

11.50 Danish information S. Aggerholm

12:25 Lunch

14.20 Application of EP approach on Dutch school building : impact of varying boundary conditions A. Van der Aa

14.50 Discussion and some preliminary conclusions

16.45 End

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2. Summary of the presentations and discussionsMost of the discussions turned to the global philosophy of the EPN, for instance:

how the EPN can have a positive impulse for the industry and how it can be a break;

the principle of equivalence and how it can be manipulated; the importance of an “as built certificate”; the link between the EPN and the actual consumption of a building; the importance of all the input parameters (i.e. target T°, occupancy pattern, …); …

Furthermore, the relevance and the importance of this WG A2 for the Annex 35 was enlightened, as EPN-Standards and Regulations are already or will be applicable in some Annex 35 countries.

2.1 Introduction & general issuesSee Annex 1, “IEA Annex 35 ‘Hybvent’ WG A2 Equivalent Energy Performance Targets in Standards and Regulations”.

S. Aggerholm: Interest of the Scandinavian countries (Finland, Norway).

2.2 Dutch approachSee Annex 2, “Regulations and standards on innovative ventilation, the Netherlands”.

In the Netherlands, the EPN is already in enforcement since 1995. One standard is valid for residential buildings (NEN 5128) and another for non-residential buildings (NEN 2916). The PowerPoint presentation give in Annex explains the importance of the ventilation on those standards.

2.3 Belgian approachSee Annex 3, “Energy Performance Standardisation and Legislation: the right track towards environmental and societal quality” and Annex 4, “Implementation of an EP legislation : Required measures and challenges and elements concerning Belgian context”.

In the Flemish region (Northern part of Belgium), an EPN regulation is in preparation and should come into force from January 1st, 2001. The PowerPoint presentation given in Annex insists on the specificity’s of the Belgian approach, which is largely based on the Netherlands’s texts.

W. De Gids: Minimum requirement for the (global) EPC but is it foreseen some minimum requirements at lower levels ? P. Wouters reply that there probably will be some additional requirements, e.g. maximum allowable U-values.

W. De Gids: What kind of temperatures are assumed to be reached in the building Imposed T°, target T° ? The choice of the T° is crucial.

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2.4 French approachSee Annex 5.

In France, an EPN regulation is in preparation. The definitive text should be ready before the Athens meeting.

P. Wouters: The French approach is not to implement a “standard” but a legislation. There is therefore a lower risk of problems with the European standards.

2.5 Danish approachSee Annex 6, “BDI-direction 184: Energy demand in buildings, Thermal insulation” and Annex 7 , “Total Energy Consumption and Resulting Environment Impact”.

In Denmark, an EPN regulation is in preparation.

W. De Gids: Are there test methods described by the standards ? No. If ventilation rate is higher that a minimum (1.2 l/s/m²), the allowed energy level

increases.

2.6 Application of EP approach on Dutch school building : impact of varying boundary conditionsSee Annex 8, “Application of EP approach on Dutch school building”.

P. Wouters: Occupancy: not only the occupancy level but also the pattern varies. P. Wouters: Given the very large impact of the variation in realistic input data, the

industry may have more interest to contact five energy consultants than to develop better technology.

W. De Gids: Equivalence Principle: you should do a simulation of a “usual” school of the same size, occupancy,… and show that your project perform better that this “reference”.

2.7 General discussion P. Wouters, W. De Gids: Philosophy of the standard: do you want to be as close as

possible to the reality or do you want to calculate a standardised consumption ? “It must be as waterproof as possible, but do not try to find the last gap” (Dutch wisdom).

W. De Gids: Equivalence principle: you should not be too optimistic if you do not want take the risk that your calculation could be refused.

A. Van der Aa: What kind of model you use ? D. Van Orshoven: People who knows the programs very well can say which program to use in which case in order to have the best result.

As built certificate: the government does not change his position but checks if you have built according to the building permit or something similar that fulfils the requirement. In the Netherlands, the municipality should check if you have built as the building permit. Therefore, the building permit is (quasi-)equivalent to an “as built certificate”. The situation is different in Belgium, where everything is not yet known when you ask your permit.

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The guidelines should not only be applicable to hybrid ventilation but to the other aspects.

2.8 Work to be done for the Athens meetingThe main output of our work should be a source book concerning the philosophy of the equivalence principle for (innovative) systems in relation to the EP approach with as example (hybrid) ventilation.

See Annex 9, “Template for reporting national approaches in relation to EP requirements”.

For countries where there are two situations (present, future), the report should be filled twice.

If some requirement are not in the EP approach but in other regulations, it should be mentioned also under the first point “legislation”.

What kind of public do we want to reach ? How to make the source book available to the public ? Short paper report / CD-ROM / Internet to be discussed at the Athens meeting.

The aim is also to convince the other participants of the IEA Annex 35. Gronge school. How should be it evaluate if it was built in Belgium, Denmark,

France or Netherlands ?

3. Action listNr. Task description By When1. NATIONAL status : Prepare template and distribute for comments BBRI 4.22. NATIONAL status : Send suggestions for comments All 20.23. NATIONAL status : send updated document BBRI 3.34. NATIONAL status : fill in for your country and send it to BBRI All 24.3

5. NATIONAL status : make synthesis presentation BBRI before Athens

6. EXAMPLES : document presenting Dutch school project C&H

7. EXAMPLES : ask Norwegians information about their hybrid ventilation concepts (school and heat recovery systems)

beforeAthens

8. GENERAL : ASK OA FOR SMALL WG meeting BBRI9. REPORT : make proposal for deliverables of this WP all

10. MEETING : present at next meeting outcome of our work and relevance for Annex 35

AnnexesAnnex 1, “IEA Annex 35 ‘Hybvent’ WG A2 Equivalent Energy Performance Targets in Standards and Regulations”. PowerPoint Presentation.

Annex 2, “Regulations and standards on innovative ventilation, the Netherlands”. PowerPoint Presentation.

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Annex 3, “Energy Performance Standardisation and Legislation: the right track towards environmental and societal quality”. Paper.()

Annex 4, “Implementation of an EP legislation : Required measures and challenges and elements concerning Belgian context”. PowerPoint Presentation.

Annex 5, “French approach”. Slides. (*)

Annex 6, “BDI-direction 184: Energy demand in buildings, Thermal insulation”. Paper. (*)

Annex 7 , “Total Energy Consumption and Resulting Environment Impact”. Slides. (*)

Annex 8, “Application of EP approach on Dutch school building”. PowerPoint Presentation.

Annex 9, “Template for reporting national approaches in relation to EP requirements”.

() Distributed during the meeting

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Work Group A3Comfort requirements and energy targets

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Work Group A4Application of analysis methods in hybrid ventilation designAction List

Distribution of relevant material for development of design procedure

Summaries of UK work on design procedure (incl. References and NiteCool predesign checklist). John Palmer distributes material to workgroup by December 1, 1999

Summary of Annex 23 work on whole building design procedure. Søren Aggerholm distributes material to workgroup by December 1, 1999

Comments on preliminary design procedure presented at the meeting, including suggestions to design phases, suggestions to changes or missing items etc.

Everyone send comments to all workgroup participants by December 1, 1999

Input from John Palmer1. Web Address for running the NiteCool Sketch design tool over the Web, and

the associated manual and workbook is:

<http://projects.bre.co.uk/refurb/nitecool>

2. Attached is a Word based hypertext document dealing with refurbishment ofoffices avoiding air-conditioning by using natural and hybrid ventilation.Please feel free to put it on the website.<<WEB-das.doc>>

3. References for other material:

BRE Digest 399 'Natural ventilaiton in non-domestic buildings'.October 1994

Natural and Low Energy Ventilation Strategies - retrofitting UKoffices" A New Practice Case Study118, BRECSU

Night cooling control strategies.' Technical appraisal 14/96 BSRIA.J Fletcher, AJ Martin.

Kendrick C, Martin A, Booth W, "Refurbishment of air-conditionedbuildings for natural ventilation", BSRIA Technical Note TN 8/98, August1998, ISBN 0 86022 498 8.

Energy Consumption Guide 19; Energy Consumption of Office Buildings.BRECSU.

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http://projects.bre.co.uk/refurb/nitecool


Work Group B1Incorporation of thermal stratification effects in network modelling

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Work Group B2Methods for vent sizing

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Work Group B3Input Data BankAction List

To collect as much of the experimental data as possible by the April 2000 meeting. This should be sent at the earliest opportunity to MO. The data format should be:

Windows Word 97 for descriptive parts (hard copy for detailed drawings), and

Windows Excel 97 for numerical parts (numerical data at stated measured accuracy).

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Work Group B4Development of Probabilistic Analysis Methods for Hybrid VentilationAction List

MP, GF (I) Investigate Natural Airing Devices and openings

YL (AU) Literature study, One-zone model, inhabitant behaviour

TC (J) CFD approach, sensitivity analysis, Two-zone model

FH (CA) Wind (incl. direction), solar radiation, external temperature

HB (DK) Probabilistic multizone model, inhabitant behaviour, external temperature

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Contribution to Workgroup B4 “Development of Probabilistic Methods”

A probabilistic approach to the study of Natural airing devices G.V. Fracastoro, M. Perino, Politecnico di Torino, Italy.

IntroductionSometimes openings are realised in the external walls of buildings as a means to provide fresh air from outside without using mechanical ventilation. Such openings may be fixed, or manually adjustable, or automatically controlled.

A special case is when such openings are recommended by gas utilities or imposed by gas utilisation Standards, whenever a gas combustion appliance is present in a residential building, to ensure that

1. combustion air may freely circulate across the building envelope in order to be provided to the combustion appliance

2. an excessive pressure drop does not hinder domestic extraction kitchen hoods to work properly

3. the air change rate induced by such openings improves the IAQ in those cases when the combustion gases produced by e g a gas fired kitchen range used for cooking are not removed by an extraction hood, but remain into the living space

In all cases in the following such openings will be called "natural airing devices" (NAD).

It must be clear that there may not be any warranty about the minimum amount of air renovated by a NAD, because this will depend upon the natural forces present in every specific situation on the building facade. Therefore it may be useful to integrate such systems with a mechanical ventilation system (MVS), thus realising a hybrid ventilation system (HVS).

It may be useful, however, to have an indication about the yearly number of hours during which a NAD will be providing a certain amount of air. Even if some air movement will always be present, due to local turbulence forces, air is forced through the building by two main forces:

wind temperature difference (stack effect). There are also two main models of natural ventilation through a NAD: cross ventilation single-sided ventilation

Wind speed and direction are the main causes for "cross ventilation", whose amount depends also on the building shape and orientation, on the internal partitions of the house, and on the position of internal doors (closed or open). These important factors are rather unpredictable.

On the other hand, "single-sided ventilation" is generally produced by stack effect, and even if this effect may also be influenced by the fluo-dynamic interaction between the

07-05-23 45


rooms, it is possible to easily model a "worst case scenario", where the room in which a NAD is present is virtually isolated from the rest of the building (doors tightly closed). In this case the air flow rate will depend only on the stack effect acting on the NAD, and may be calculated as a function of indoor-outdoor temperature difference and the geometrical features of the NAD.

Frequency distribution of flow ratesKnowing the air temperatures indoors and outdoors, the air flow rates through a NAD may, for example, be calculated using the following simplified expression [1]:

where the discharge coefficient Cd is given by [1]:

and

/2

From the TRY of a location the hourly temperature values are known, and the time profile, the frequency and the cumulated frequency of air flow rates may be calculated. As an example, such values are plotted in figures 1 - 3 for different size square NAD’s in Bologna, a city located in the Po Valley, Northern Italy. Values for non square areas may be found using the following expression

where c may be found from figure 4, as a function of w/H.

References[1] ASHRAE, Handbook of Fundamentals.

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Work Group B5 Wind flows through large openings Action List

1. Progress report on windtunnel tests (M.S)

2. Progress report on CFD predictions ( Y.L,M.P)

3. Report on literature survey (M.O, M.S, )

(underlined is responsible)

In addition to this F.H will explore the possibilities to use their windtunnel.

07-05-23 61


WG-B5 WIND FLOW THROUGH LARGE OPENINGS

Progress Report

Wind Tunnel Studies

Literature Survey

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1. Large openings –Wind tunnel Measurements

1.1 Statement of the problem When can recorded pressure distribution (surface pressure coefficients) obtained from a sealed object be used to predict the flow rate through openings in the same object ?

1.2 IntroductionThe litterature survey revealed that work carried out did involve only fairly complex pbjects ( houses of complex geometry exposed to the atmospheric boundary layer). The results were usually correlated against the porosity

[%]

The purpose of the windtunnel tests is to explore the pressure distribution on objects of simple shapes in order to be able to understand which parameters govern the pressure distribution and in particular the difference in pressure distributions between solid objects and the same object provided with openings. As a basic configuration was chosen a circular disk. Starting from this basic configuration more complicated shapes are created, see Figure 1.

Figure 1 Configurations

Figure 2 shows sketches of the expected flow patterns without and with a hole in the disk. With no hole the flow has a stagnation point in the centre. In case there is hole disk the flow has to make a choise either flow through the hole or to be deflected radially outwards along the surface of the disk. In this case we should expect to have a circular stagnation line.

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1 a

1 b

c e n t r e

c e n t r e

c e n t r e

o f f c e n t r e

o f f c e n t r e

o f f c e n t r e

2 a

2 b

3

4

x c rh d

H

W


Figure 2 Sketch of flow over a solid plate and a plate with a hole

1.3 Experimental set-up

1.3.1 Wind tunnel A building aerodynamics has been used. The windtunnel has a working length of 11 meters and a cross section of 1.5 x 3.0 meters, for details see Appendix.Wind Tunnel.

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Dividingstream line

stat

Dividingstream lines

rrhrsta t


1.3.2 Disk and pressure measurements A disk with a diameter W= 150 mm and a thickness d=10 mm was fabricated from Plexiglas. Along the diameter of the model 26 small holes were drilled. To the holes thin tubes were connected and the other end was conntected ot a valve of type Scanivalve. The pressure was recorded with a transducer of type Druck PDCR22.

To obtain as uniform velocity as possible the disk was placed in the centre of the working section of the windtunnel, see Fig. 3.

Figure 3 Disk placed in the centre of the windtunnel

The disk was fitted with 8 wires and its angle was adjusted perpendicular towards the airflow with “vant” screws, see Figures 4 and 5.

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Figure 4 The disk installed in the wind tunnel; front view showing the removable inserts

Figure 5 The disk in the windtunnel; rear view showing the tubes from pressure tappings

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To obtain an average pressure value the signal was sampled with a frequency of 10 Hz over a period of 15 seconds. Because the tunnel is a sealed channel and without cooling the temperature will rise when running. The pressure values measured in the tunnel are therefore standardised to normal conditions, 20 degrees C and 760 mm Hg.

The total pressure and the static pressure, p0 , used as as reference to the Cp- calculations, were measured on the same height in the tunnel as the disk but approximately 1 meter upstream and 0.8 meter sideways from the tunnel centre. The Cp

value is defined as

wherep = pressure Pap0 = static free-stream pressure Pa = density of air kg m-3

U0 = wind speed at model centre ms-1

1.4 Experimental programmeThe tests were conducted with configuration 1a and 2a.

1.4.1 Configuration 1aIn the centre of the model a hole was drilled with a diameter of 75 mm. Five

removable inserts were fabricated with the diameters of 55, 35, 16 , 10, and 7.5 mm., see Figures 4 and 5.. The porosity is given in the table below.

Diameter of hole

[mm]1.4.1.1.1.1.1 Porosity

[%]

0 0

7.5 0.25

10 0.44

16 1.14

35 5.44

55 13.44

75 25

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The solid plate is the refernce case. As an intermediate case between a solid disk and disk with a hole tests were conducted with a disk provided with a 35 mm hole and with a rubber membrane covering the hole. In one case the membrane was firmly streatched and in another test the membrane had a slack of 5 cm.

Figure 4 Disk with rubber membrane

1.4.2 Configuration 2bHoles with diameter 7.5, 10, 16 1 and 35 mm were located at XC = 60 mm, se Fig. 1.

1.5 Results

1.5.1 Rubber membrane No discernible difference in pressure distribution compared to the solid disk.

1.6 Configuration 1a

1.6.1 Pressure measurements

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1.6.2 Velocity measurements The velocities on the rear side of the disk were recorded with a hot film probe.

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1.7 Case 2a

1.7.1 Pressure measurements

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APPENDIX 1 Measurement data

Distance from the centre [mm]

1.7.1.1 Configuration 1a

Centric hole

solid plate

Rh 3.75 Rh 5 Rh 8 Rh 17.5 Rh 27.5 Rh 37.5

Cp 1.7.1.2p

1.7.1.3p

1.7.1.4p

Cp Cp Cp

72.5 0.35 0.348 0.356 0.354 0.351 0.381 0.44

70 0.548 0.553 0.548 0.543 0.559 0.598 0.654

67.5 0.629 0.635 0.643 0.634 0.643 0.689 0.748

65 0.714 0.722 0.717 0.709 0.734 0.776 0.832

62.5 0.749 0.760 0.764 0.758 0.771 0.814 0.874

60 0.798 0.801 0.787 0.788 0.816 0.860 0.918

57.5 0.816 0.828 0.829 0.829 0.838 0.883 0.943

55 0.845 0.858 0.852 0.852 0.870 0.920 0.969

52.5 0.872 0.876 0.881 0.88 0.893 0.940 0.987

50 0.888 0.895 0.896 0.895 0.917 0.956 1.002

47.5 0.905 0.915 0.909 0.911 0.930 0.978 1.004

45 0.922 0.931 0.927 0.922 0.949 0.991 0.995

42.5 0.927 0.934 0.942 0.939 0.965 0.994 0.953

40 0.939 0.948 0.949 0.949 0.971 1.003 0.842

35 0.957 0.969 0.972 0.967 0.993 0.994

32.5 0.963 0.975 0.98 0.977 0.998 0.960

30 0.973 0.984 0.985 0.983 1.008 0.865

25 0.986 0.991 0.996 0.997 0.993

22.5 0.988 0.993 1.001 0.998 0.975

20 0.989 0.999 1.004 0.999 0.884

15 0.999 1.010 1.009 1.004

12.5 0.999 1.005 1.011 0.984

10 1.003 1.013 1.005 0.935

7.5 1.001 1.001

5 1.005 0.926 0.877

0 1.004

07-05-23 71


Distance from centre [mm]


Centric hole (hot film measurements)

Rh 3.75 Rh 5 Rh 17.5 Rh 27.5 Rh 37.5

[m/sec] 1.7.1.6 [m/sec]

1.7.1.7 [m/sec]

1.7.1.8 [m/sec]

[m/sec]

0 21.3 21 19.7 19 18.7

5 19

8.5 20.3

10 19.2 18.9

11.5 20.7

14.5 4.7

15 19.8 19.2

17.5 0

20 20.5 20

24 6.3

25

27.5 0

30 20.8

34

37.5 0

Air speed in free stream =18.5 m/sec

07-05-23 72


Distance from centre [mm]


Eeccentric hole

solid plate Rh 3.75 Rh 5 Rh 8 Rh 17.5

Cp 1.7.1.10 Cp

1.7.1.11 Cp

1.7.1.12 Cp

Cp

-72.5 0.351 0.344 0.352 0.348 0.363

-67.5 0.623 0.617 0.632 0.632 0.653

-62.5 0.75 0.743 0.753 0.752 0.786

-57.5 0.816 0.806 0.813 0.825 0.859

-52.5 0.869 0.856 0.861 0.875 0.918

-47.5 0.889 0.884 0.902 0.91 0.949

-42.5 0.931 0.913 0.933 0.941 0.99

-35 0.944 0.95 0.961 0.974 0.943

-27.5 0.966 0.977 0.987 0.995

-22.5 0.974 0.984 0.924

-14.8 0.993

-9.5 0.995 0.856

-4.7 0.993 0.976 0.968 0.88

0 1 0.99 0.992 0.981

7.5 0.994 0.99 0.995 0.996 0.911

12.5 0.991 0.979 0.989 0.994 0.983

22.5 0.974 0.98 0.985 0.985 1.001

32 0.966 0.963 0.959 0.963 0.968

40 0.935 0.929 0.936 0.936 0.951

45 0.915 0.903 0.912 0.914 0.923

50 0.883 0.881 0.881 0.886 0.905

55 0.843 0.835 0.836 0.843 0.854

60 0.777 0.765 0.768 0.776 0.784

65 0.704 0.69 0.708 0.709 0.72

70 0.53 0.528 0.536 0.54 0.559APPENDIX 2 Windtunnel

07-05-23 73


07-05-23 74


2. Literature SurveyReferencesAynsley, R.M. (1982) "Natural ventilation model studies". Proc. Of the International Workshop on Wind Tunnel Modelling Criteria and Techniques in Civil Engineering Applications, Gaithersburg, MD, Cambridge University Press, Cambridge.

Brown, W.G. & Solvason, K. R. (1962) "Natural convection through rectangular openings in partitions - 1. Vertical partitions. International Journal of Heat and Mass Transfer, Vol. 5, pp 859-868.

Carey P S, Etheridge D W (1999) "Direct wind tunnel ,modelling of natural ventilation for design purposes". Building Serv. Eng. Res. Technol.20(3), pp 131-142.

Chandra, S. Kerestecioglu, A.A., Fairey, P.W. & Cromer, W. (1982) "Comparison of model and full scale natural ventilation studies". Proc. of the International Workshop on Wind Tunnel Modelling Criteria and Techniques in Civil Engineering Applications, Gaithersburg, MD,Cambridge University Press, Cambridge.

Cockcroft, J. P. & Robertson, P. (1976) "Ventilation of an enclosure through a single opening". Building Environment, 11(1), pp 29-35.

Ducarme, D. Vandaele, L. & Wouters, P. (1994) "Single-sided Ventilation: A Comparison of the Measured Air Change Rates with Tracer Gas and with the Heat Balance Approach". 15th AIVC Conference, Buxton, Great Britain, 27-30 September.

Eftekhari, M.M. (1995) "Single-sided natural ventilation measurements". Building Serv.Eng.Res. Technol. 16(4) pp. 221-225.

Etheridge D W (1998) "Dynamic insulation and natural ventilation". Feasibility study.

Building Serv. Eng. Res. Technol. 19(4) pp 203-212.

Etheridge D W (1999) "Unsteady flow effects due to fluctuating wind pressures in natural ventilation design - instantaneous flow rates". Building and Environment 35, pp 321-337.

Etheridge D W (1999) "Unsteady flow effects due to fluctuating wind pressures in natural ventilation design - mean flow rates". Building and Environment 35, pp 111-133.

Freskos, G.O. (1998) "Influence of various factors on the predictions furnished by CFD in cross-ventilation simulations". Proceedings of Roomvent 98: 6th International Conference on Air Distribution in Rooms, Vol. 1, pp 483-490.

Fritzsche, C. & Lilienblum, W. (1968) "Neue Messungen zur Bestimmung der Kälteverluste an Kühlraumtüren". Kältetechnik-Klimatisering. 20 Jahrgang, Heft 9, s 279-286.

Graf, Adolf (1964) "Theoretische Betrachtung über den Luftaustausch zwischen zwei Räumen". Schweizerische Blätter für Heizung und Lüftung, Vol. 31, No. 1, pp 22-25.

07-05-23 75


Husslage, J. (1990) "Procedures for calculating ventilation in rooms with open windows". CIB W67 Symposium on Energy, Moisture and Climate in Buildings. Rotterdam, The Netherlands.

Iino, Y. Kurabuchi, T. Kobayashi, N. Arashiguchi, A. (1998) "Study on airflow characteristics in and around building induced by cross ventilation using wind tunnel experiment and CFD simulation". Proceedings of Roomvent 98: 6th International Conference on Air Distribution in Rooms, Stockholm, Sweden, Vol. 2, pp 307-314.

Kato, S. Murakami, S. Mochida, A. Akabayashi, S. Tominaga, Y. (1992) "Velocity-pressure field of cross ventilation with open windows analyzed by wind tunnel and numerical simulation". Journal of Wind Engineering and Industrial Aerodynamics, Vol. 41-44, pp 2575-2586.

Kiel, D.E. & Wilson, D.J. (1986) "Gravity driven flows through open doors". 7th AIVC Conference, Stratford-upon-Avon, UK. Paper 15.

Lane-Serff, G.F. Linden, P.F. & Simpson, J.E. (1987) "Transient flow through doorways produced by temperature differences". RoomVent 87, Stockholm, Session 29.

Linden, P.F. & Simpson, J.E. (1985) "Buoyancy driven flow through an open door". Air Infiltration Review, Vol. 6, No. 4. August.

Maas van der, J. Bienfait, D. Vandaele, L. Walker, R. (1991) " Single sided ventilation. Air movement and ventilation control within buildings". 12th AIVC Conference, Ottawa, Canada, Vol. 1, pp 73-98.

Maas van der, J.(edit) (1992) "Air flow through large openings in buildings". International Energy Agency. Subtask-2. Technical Report.

Malinowski, H.K. (1971) "Wind effect on the air movement inside buildings". Proc. 3rd Int. Conf. "Wind effects on buildings and structures", 125-134, Saikon Shuppan, Tokyo.

Murakami, S. Kato, S, Akabayashi, S. Mizutani, K. & Kim, Y-D. "Wind tunnel test on velocity-pressure field of cross-ventilation with open windows". ASHRAE Transactions, Vol. 97, Part 1, pp. 525-538.

Nielsen, A. & Olsen, E (1993) "Measurements of air change and energy loss with large open outer doors". 14th AIVC Conference, Copenhagen, Denmark. 21-23 September.

Santamouris, M. Argiriou, A. Asiamkopoulos, D. Klitsikas, N. & Dounis, A. (1995) "Heat and mass transfer through large openings by natural convection". Energy and Buildings 23, 1-8.

Schaelin, A Maas van der, J. & Moser, A. (1992) "Simulation of airflow through large openings in buildings". ASHRAE:Symposia, Paper BA-92-2-4.

Shaw, B.H. (1972) "Heat and mass transfer by natural convection and combined natural convection and forces air flow through large rectangular openings in a vertical partition". Paper in: Heat and Mass Transfer by Combined, Forced and Natural Convection (Symposium 15, Sept. 1971), London. The Institution of Mechanical Enigneers, pp. 31-39, 64-68.

07-05-23 76


Shaw, B.H. & Whyte, W. (1974) "Air movement through doorways - the influence of temperature and its control by forced airflow". The Building Services Engineer, 42, Dec: 201-218.

Tamm, W. (1966) "Kälteverluste durch Kühlraumöffnungen". Kältetechnik - Klimatisierung, 18. Jahrgang, Heft 4. S 142-144.

Warren, P.R, (1977) "Ventilation through openings on one wall only". Int.conf. on Heat and Mass Transfer in Buildings", Dubrovnik, Yugoslavia. In: Energy Conservation in Heating, Cooling and Ventilating Buildings, Vol. 1 eds. C.J. Hoogendoom and N.H. Afgar, pp 189-209, Hemisphere, Washington, DC.

Vickery, B. J. & Karakatsanis, C. "External wind pressure distributions and induced internal ventilation flow in low-rise industrial and domestic structures". ASHARE Transactions, Vol. 93, part 2, pp 2198-2213.

Yamashita, K. Yamazaki, H. Gotoh, T. Watanabe, T. Miki, N. Maeda, Y. (1996) "Calculation method of cross ventilation in a room". Indoor Air'96, proceedings of the 7th International conference on Indoor Air Quality and Climate, Nagoya, Japan, Vol. 2, pp 509-514.

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Work Group B7Integrate or implement control strategies into models

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Work Group B8Climate DataAction List

i. Conversion of wind and temperature data from the weather station to the building site, and, further, to the building itself.Measurements at Belgian site have already started. They will continue and Peter Wouters together with Willem and Van der Aa will produce a preliminary report on measurements before the next working meeting (march 2000)

ii. Define the feasibility and energy savings potential of Hybrid Ventilation as a function of Outdoor ClimateMalcolm Orme has offered to provide information about NatVent and CIB WG 21 work, namely on how the Outdoor Climate affects the design and choice of natural ventilation components (end of November ’99)Gian Vincenzo Fracastoro will produce a preliminary report on the Preliminary evaluation of HybVent feasibility depending on Outdoor Climate (march 2000)

07-05-23 79


Workgroup B8 “Climate Data”

Preliminary evaluation of HybVent feasibility based on Outdoor ClimateG.V. Fracastoro, Politecnico di Torino, Italy.

IntroductionWhy are some countries so reluctant to use forced ventilation even in commercial and educational buildings ? One reason has to do with the technological level of the country itself, along with the availability and cost of electric energy, but another one is definitely related to tradition, and tradition has a lot to do with the local climate.

On the other hand, there are countries which tend to solve any kind of IAQ problem, even in residential buildings, with a mechanical system, and do not consider the possibility of integrating such systems with natural forces. Again, one reason is technology, but another one has to do with climate.

As an example, Italy, UK, Ireland, Belgium seem to belong to the first group, while Canada, Sweden, Finland, and, to a certain extent, the US seem to belong to the second group. It cannot be a coincidence that the climate of the first group of countries is by far milder than the second group’s.

However, it is clear that there may not be any warranty about the minimum amount of air renovated by natural ventilation (NV), because this will depend upon the natural forces acting in every specific situation on the building facade. Therefore it may be useful to integrate such systems with a mechanical ventilation system (MVS), thus realising a hybrid ventilation system (HVS).

Even if some air movement will always be present, due to local turbulence forces, air is naturally forced through the building by two main forces:

wind

temperature difference (stack effect).

So, a question may also be raised about the feasibility of an HVS. Are all climates suitable for HVS ? Are HVS unsuitable in too mild climates because wind velocity and temperature differences are not sufficiently large ? Or, are they unsuitable in too rigid climates because natural forces are so strong that they would produce too strong air flows and annoy the occupants with cold drafts ?

To these questions we should add one more question which is not related to the climate, but to the hygienic conditions of outdoor air: is outside air sufficiently clean to allow direct entrance into the living space without suitable filtration?

Feasibility of HVSThe feasibility of an HVS is therefore related to outdoor climate and air quality, and a careful evaluation should precede:

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the introduction of an MVS in climates and building typologies where NV is usually adopted, or

the introduction of NV in climates and building typologies where MVS are usually adopted.

Introducing MV in naturally ventilated buildingsIn this case an objective reason to introduce an MVS is that natural forces are not sufficient to provide enough fresh air to the house. This actually happens in mild climates, and the traditional solution is window opening. Being an action produced by a subjective evaluation, not always it will be done when there is an actual need, e g, when the need for ventilation is not occupant-related, but, for instance, building-related (humidity and mould growth).

A rational procedure to assess the feasibility of HVS should then be the following:

The pressure difference across the building envelope may be calculated as:

(1)

07-05-23 81

Determine statistical values of pressure difference across the building envelope for a

certain building shape and location

BUILDING LOCATIONMETEO

TRY

Determine minimum p, likely to produce a sufficient air

change rate

pj = pmin

j

Depending on the value of j, one should decide whether MV is

necessary or not, or the permeability of the building should be increased


where zpn = neutral plane levelw = wind velocity = mean outdoor-indoor air densityT = mean outdoor-indoor temperature

The building related features (z - znp) and Cp will assume a reference value for each building typology, while the climate data (temperature difference and wind speed) should be chosen so as to be representative of the location. A tentative list of reference values of (z - znp)ref and Cp,ref values is shown in Table 1, along with typical permeability values Cref (Table 2).

Introducing the reference values (z - znp)ref and Cp,ref in Eqn. (1) and running such equation for each hour of the TRY (Test Reference Year) of a certain location one may obtain the frequency and cumulated frequency distribution of p, as shown in Fig. 1.

Table 1 - Typical NV parameters for different building typologies and surrounding areas (tentative).

Code Building typology and surrounding area (z - zpn)ref

mCp,ref

IL1 Isolated single-family house 2 0.6SL1 Sheltered single-family house 2 0.4IL2 Isolated high-rise 10 0.75SL2 Sheltered high-rise 10 0.5

Table 2 – Typical permeability values for different building enclosures, referred to overall area of enclosure.

Permeability Low Medium HighCref [m3h-1m-2] at 1 Pa 0.1 0.15 0.2

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One may now find, using the values air permeability shown in Table 2 the minimum pressure difference pmin required to have more than a certain number of ach's, shown, as an example, in Fig. 2 and 3 for, respectively, 0.3 and 0.5 ach. For example, for 0.3 ach, C = 0.15 m3/h/m2 and V/A = 1.5 m, one will find in Figure 2 pmin = 5.5 Pa, corresponding in Figure 1 to a cumulated frequency of about 25 %. This means that for about 75 % of the time this pressure difference will be exceeded and NV will be sufficient. In order to cover also the 25 % of the remaining time, either the building needs an integration with MV, and thus will make use of a HVS, or the permeability of the enclosure has to be increased.

On the other hand we may probably expect subjective contraindications, i e, a strong resistance of people to the introduction of MVS: noise, investment and running costs, need for maintenance may hinder the spreading of such systems. Even more, the usually mild outdoor climate will encourage the old habit of window opening, thus cancelling the effect of the MVS.

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Fig. 1 - Pressure difference frequency and cumulated frequency (imaginary location)

0

200

400

600

800

1000

1200

1400

1600

1800

2000

0 2 4 6 8 10 12 14 16 18 20 22 24

Pressure difference (Pa)

freq

uenc

y (h

ours

)

0

20

40

60

80

100

120

Cum

ulat

ed fr

eque

ncy

(%)

no. hourscum freq.


Introducing NV in mechanically ventilated buildingsIn this case, the drawbacks with the use of NV are related with the fact that outdoor air

07-05-23 84

Fig. 2 - Pressure difference needed to produce ach = 0.3 for different permeabilities and building V/A

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5

Building V/A (m)

Pres

sure

diff

eren

ce (P

a)

C = 0.2

C = 0.15

C = 0.1

Fig. 3 - Pressure difference needed to produce ach = 0.5 for different permeabilities and building V/A

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5

Building V/A (m)

Pres

sure

diff

eren

ce (P

a)

C = 0.2

C = 0.15

C = 0.1


1. is not thermally treated, 2. is not filtered, and 3. noise may penetrate the building along with air.

The problem with bad outdoor air quality is particularly hindering for NV, because it cannot be solved but partially, due to the high pressure drop across high performance filters. Outdoor air quality and noise issues are not dealt with in this context.

The impossibility to thermally treat the outdoor may lead to a cold draft problem. When outdoor air is naturally forced by pressure differences into the building through a NAD (Natural Airing Device), a stream of air flows into the inhabited space. As the natural pressure head across the NAD increases, the air flow rate will increase and it may assume high speed, high turbulence and, if the outdoor temperature is low, low temperature as well. Pressure heads in the order of 10 Pa or more, associated with T in the order of 10 K or more, are potentially a cause of cold draft. A possible solution to avoid cold draft risk would be NAD's which automatically reduce their cross section when the natural pressure head becomes too high (pressure-sensitive NAD), in such a way that the flow rate, and associated cold draft, does not increase too much.

The procedure outlined previously for the introduction of MV may be followed also for this case, in which the % of time during which the maximum allowable pressure difference is exceeded is found.

Depending on this frequency, a decision may be taken about the feasibility of adding NV to the building, thus making it a HV building.

07-05-23 85

Determine statistical values of pressure difference pj across the building envelope for

a certain building shape and location

BUILDING LOCATIONMETEO

TRY

Determine pmax, above which relevant cold drafts may occur

pj = pmax j

Determine whether the frequencyj with which cold drafts may occur

is acceptable or not


Work Group Final report

Preliminary outline of “principles of Hybrid Ventilation”

Preliminary Outline

1) Introduction

What are the benefits? Definitions What are the systems like? Examples (simple description) Advice to achieve good systems/buildings How can systems be controlled?

2) When can the systems be used, what are the minimum requirements?

ParametersOutdoor climate (wind, humidity, temperature, solar radiation)Outdoor air quality (dust, gases, pollution)Building designBuilding use (human activities, no. of people, activity level, clothing,

machinery)Thermal comfort requirements (air and surface temperatures, velocities)IAQ requirements (particles, gases, odour, noise)Remaining internal loads

Hybrid ventilation can probably be used/not be used

3) Decision and analysis tools

Hybrid ventilation strategyVentilation strategyControl strategyCost restrictions Best possible “solution” for “my” building

Analyzing the strategiesTools (hand calculation (air flow), simulation programs (energy)), see

app.

Is the design good enough?Cost effectiveFirst cost, operating costIAQ satisfied?

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Members of Group: Helmut Feustel, Per Olaf Tjelflaat, Henrik Brohus, Marco Perino, Christian Inard, Malcolm Orme, Hans Leonhardt,

Gérard Guarracino

Tasks: Draft the contents of “Principles of Hybrid Ventilation


Thermal comfort?Electrical energy?Thermal energy?CO2?

Commisioning and monitoringWhat and how to monitor?How to analyze data?

2) Examples

3) Appendix

Control strategies/BMS Analysis Methods Systems Components

07-05-23 87


Pilot Studies

Country Building name Location Contact Person Draft Report

Australia Wilkinson Building Sydney David Rowe OK!

Belgium IVEG Hoboken Nicolas Heijmans

Belgium PROBE Limelette Nicolas Heijmans

Denmark B&O HQ Struer Ole Juhl Hendriksen

Italy Palzzina I Guzzini Recanati Paolo Principi

Japan The Liberty Tower Meiji Shinsuke Kato

Japan Tokyo Gas Earth Port Tokyo Shinsuke Kato

Japan Fujita Technical Center Shinsuke Kato

Norway Mediå school Grong Per Olaf Tjelflaat

Norway Jaer school Oslo Peter Schild

Norway Lavollen Trondheim Per Olaf Tjelflaat

Sweden Tangå School Falkenberg Åke Blomsterberg OK!

The Netherlands Library Utrecht Utrecht Ad van der Aa

The Netherlands Waterland school Leidschenveen Ad van der Aa

07-05-23 88

IEA ECBCS Annex 35 : HybVent

89


Pilot study report :

Wilkinson BuildingSydney, Australia

1. GENERAL INFORMATION

1.1.1 Building nameWilkinson Building at the University of Sydney

1.1.2 Building typeEducational (Faculty of Architecture). 25 academic and administrative offices.

1.1.3 Principal researcherDavid Rowe, Honorary Senior Lecturer

1.1.4 Other participantsNone.

1.1.5 Principal objectivesDefinition of relationship between energy consumed by the climate control system and outdoor weather.Definition of relationship between occupant controlled indoor temperatures and outdoor weather.Definition of the relationship between mean clothing insulation values and outdoor weather.Comparison of occupant sensations of thermal comfort and air quality with those of occupants of other buildings.Comparison of prevalence of symptoms of sick building syndrome with those of occupants of other buildings.Periodic sampling of CO2, particulates, VOCs and microbiological contaminants of indoor air.

1.1.6 Start date/end date1 August 2000 to 31 July 2001.

1.1.7 Report dateEnd December 2001

1.1.8 References

1.1.9 Comments25 academic and administrative staff offices in the Wilkinson building (Faculty of Architecture) are naturally ventilated through operable doors and windows. They have been retrofitted with supplementary refrigerated cooling and heating equipment which is also controlled on demand independently by occupants of the separate rooms.Energy consumption as supplied by a dedicated submain has been monitored continuously at half hourly intervals since the beginning of December 1997 and this will continue through the test period. Weather data is also recorded on site at half hourly intervals.

90


Surveys of background perceptions of thermal comfort and air quality and of prevalence of symptoms associated with the sick building syndrome have been conducted before and after installation of the refrigerated fancoil units and can be compared with the results of similar surveys of 23 other office settings in a database in my possession.

2. TEST SITE DESCRIPTION

2.1 Geographic information

2.1.1 LocationSydney, Australia. Longitude 151 deg. E; latitude 33 deg. S.

2.1.2 Elevation90 metres.

2.1.3 TerrainSuburban, low rise buildings and parkland.

2.1.4 OrientationSouth, south east and north west.

2.1.5 CommentsCooling and heating loads are perimeter dominated in all spaces.

2.2 Climate information

2.2.1 Air temperatureJanuary mean max 25.7oC, mean min. 18.8 oC.June mean max. 18.8 oC, mean min 9.6 oC.Hour by hour TRY weather data is available for Sydney 1981.

2.2.2 Daylight/insolationMean hours sunshine per day: January 7.2; June 5.2.Mean insolation: January 6,539 Wh/m2, June 2,456 Wh/m2.

2.2.3 % frequency wind speed versus wind directionWind speed mean for year 11.6 km/hr. Mean for January 12.3 km/hr. For June 11.6 km/hr. Winds are mainly from the north to east in summer and from south to west in winter.

2.2.4 Degree day informationHeating degree days, 18 degree base: 642Cooling degree days, 26 degree base: 3Solar excess degree hours 8,677Cooling degree days as quoted do not reflect the requirement for latent cooling in summer. Most designers would use a lower base temperature if data were available.

2.2.5 Cloud factorMean daily hours cloud cover January 5.9; June 5.0.

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2.2.6 CommentsThe Sydney climate can be characterised as humid sub-tropical. The months of January, February and early March are usually warm to hot with humid sea breezes. Winters are mild in comparison with Northern hemisphere places at similar latitudes.

3. BUILDING DESCRIPTION

3.1 General description

3.1.1 HistoryThe building was constructed in stages from 1960 to 1978. The section in which the study area is located was the last completed. The 25 naturally ventilated offices on which the study is focused were fitted out with supplementary refrigerated cooling and reverse cycle heating equipment at the end of 1997. The offices are also centrally heated with wall panel radiators provided as part of the original design.

3.1.2 Design philosophy for IAQ and thermal comfort, energy efficiencyand other issues of concern.

The intention of providing the supplementary equipment was to provide relief from warm humid indoor conditions which many found oppressive in summer. The design philosophy is laissez faire. Occupants are free to use the supplementary equipment in individual rooms as they see fit.A previous small pilot study had indicated that the system would tend to default to off: if conditions in a room are acceptable then the system is not turned on. The previous study had also shown that energy consumption was likely to be much less than for a conventional mechanical cooling, heating and ventilating system.Ventilation can be said to be demand controlled inasmuch as occupants open or close windows as they see fit to maintain necessary ventilation. In practice, many of them prefer to open windows and doors in pleasant weather but close them when hot dry winds occur in summer or on the colder days in winter.The building is of heavyweight construction with double brick or precast concrete panel outer walls, single brick interior partitions and reinforced concrete floors and ceilings. The roof over level 4 offices is insulated with 50 mm polystyrene blocks with coarse gravel overlay. The roof over level 5 offices is uninsulated. This produces a significant radiant heat load which is uncomfortable in summer but welcome in winter. Ceilings on levels 2 and 4 are lined with timber boarding with natural finish. Ceiling heights vary from 2700 mm to 3000 mm. The fancoil units provide air movement with very low noise levels. The building is located on a busy highway but the rooms in the study area are oriented away from the road.

3.1.3 Design processCooling loads estimated using CAMEL (Carrier Airconditioning Method of Estimating Loads). Hour by hour energy simulation performed using ESPII software to estimate energy consumption that would be expected if the spaces were mechanically heated, cooled and ventilated.

3.1.4 CommentsResults to date indicate that occupants perceive thermal comfort and air quality better than reported by people in 23 other (mainly air conditioned) settings. Energy consumption over two years has averaged about a quarter of estimated consumption if the spaces were mechanically heated, cooled and ventilated.

92


3.2 Building geometry and materials

3.2.1 PlanPlan of study areas on levels 2, 4 and 5.Not to scale.

3.2.2 ElevationNot available

3.2.3 Building formThe building is of five storeys with an overall height of approximately 16 metres.

3.2.4 VolumeTotal volume of study area 1,175 m3.

3.2.5 Floor area and materialsOccupied area, level 2: 178 m2. Floor is of 150 mm concrete with underfelt and carpet. U-value: 1.17 W/ m2 oC Level 4:158 m2. Material as for L 2. Level 5: 93 m2. Material as for L 2. Total floor area of study area is 429 m2.

3.2.6 Ceiling heightCeiling heights vary between 2700 and 3000 mm. There are no above ceiling or floor voids.

3.2.7 Facades (external walls)Level 2 Area delayed surfaces: SE - 7.3 m2; South - 39.6 m2; SW - 20 m2; Cavity brick, U-value 1.96 W/m2 oC. Area windows: SE - 30.7 m2; South - 40 m2; SW 12 m2; U-value 5.89 W/m2 oC.Level 4 Area delayed surfaces: South - 14.2 m2; SW - 26.3 m2; Cavity brick, U-value 1.96 W/m2 oC. Area windows:; South - 22.8 m2; SW 41.4 m2; U-value 5.89 W/m2 oC. Window area includes six (6) single width fully glazed external doors.Level 5 Area delayed surfaces: SE - 25.8 m2; SW - 15.3 m2; NW - 10.1 m2; NE - 10.8 m2; Cavity brick, U-value 1.96 Area windows: SE - 16.1 m2; SW - 9 m2; NW 16.9 m2; U-value 5.89 W/m2 oC.

3.2.8 WindowsMetal framed hopper type with 600 mm overhangs at window heads. Fitted with sealing strips. Areas as indicated in

3.2.9 Facades above. Occupant operated.

3.2.10 External doorsSix rooms on level 4 have fully glazed external doors opening onto a rooftop courtyard. Areas included in ìwindowî areas under

3.2.11 Number etc of roomsThere are 25 rooms in the study area. Most are occupied by a single person. Maximum occupancy is three to a room.Attics, basements, crawlspace Nil.

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3.2.12 Interior wallsRooms are divided from one another and corridors by single brick fixed walls. Total area:- level 2 - 116.3 m2; level 4 - 312 m2. level 4 - 174.1 m2. U-value 2.3 W/m2 oC.

3.2.13 Interior doors and devicesEach room has an interior access flush solid core door to corridor.

3.2.14 StairwellsNot applicable.

3.2.15 Service risersNot applicable.

3.2.16 CommentsDesign studios elsewhere and corridors adjacent to study areas on levels 2 and 4 are mechanically ventilated with outdoor air which is heated in winter.

3.3 Air leakage data

3.3.1 DoorsExternal doors have weather stripping seals. Leakage negligible when closed.

3.3.2 WindowsFitted with soft seals as for doors. Leakage negligible when closed.

3.3.3 Ventilation openings and stacksOperable windows and external doors controlled by occupants.

3.3.4 Chimneys and fluesNot applicable.

3.3.5 Communicating wallsNot applicable.

3.3.6 Structural jointsWalls are built off concrete slab floors with mortar joints. Metal window heads are fitted under downturned concrete beams.

3.3.7 Service routesServices are exposed throughout the building.

3.3.8 Other air leakage routesThrough internal doors into corridors.

3.3.9 Background leakageNo quantitative data.

3.3.10 Neutral pressureNot known.

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3.3.11 CommentsLeakage typical of reasonably tight masonry construction.

3.4 Wind pressure coefficientsNot known.

3.5 Space heatingMost of the rooms have wall panel radiators connected to a central hot water heating reticulation system from a central natural gas fired boiler. This heating system is operated during working hours (8 am to 9 pm) during a heating season from approximately 1 June to 31 August. Corridors outside the study areas on levels 2 and 4 are also heated during the same season by warm air circulated by central fans.

3.6 Ventilation

3.6.1 Ventilation principleWind driven cross ventilation through operable windows and internal doors controlled by occupants.

3.6.2 ComponentsWindows and doors.

3.6.2.1 Fresh air inletsWindows and doors.

3.6.2.2 FansNot applicable.

3.6.2.3 Heat recoveryNone

3.6.2.4 FiltrationNot applicable.

3.6.2.5 DuctsNot applicable.

3.6.2.6 Room supply and extract devicesNot applicable.

3.6.2.7 Air exhaust outletsNot applicable.

3.6.3 Frequency of operationSupplementary cooling and heating system is operated as and when required by room occupants. Hours are flexible. Research students have been known to arrive late at night and work for several hours into the very early morning. Central heating system is operated automatically during the hours mentioned above. Individual radiators are fitted with control/shut off valves.

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3.6.4 Balancing reportNot applicable.

3.6.5 Ventilation rateNot applicable.

3.6.6 Any recirculation between roomsNot applicable.

3.6.7 Space coolingWall hung refrigerated fancoil units connected to a variable refrigerant flow condensing unit. The unit is modular and can operate at very low loads with high efficiency. Fancoil units are independently under the control of room occupants.

3.6.8 CommentsOccasional spot checks have shown CO2 content at between 450 and 800 ppm.

3.7 Construction materials, properties and techniquesThe structure is of reinforced concrete with double brick cavity walls and metal framed windows. Internal partitions are of fixed single brick construction. Roof over level four rooms is a concrete slab with 50 mm polystyrene block insulation overlaid with 50 mm coarse gravel. The roof over level 5 rooms is of uninsulated concrete.

3.8 Internal loads

3.8.1 Patterns of occupancyHours are flexible. All staff have out-of-hours access. Some work into evenings and research students may work long and irregular hours. For energy simulation hours have been scheduled as 30 percent at 9 am with maximum 90 percent and varying through the day to 20 percent 10 pm. There are 19 people on level 2; nine on level 4 and nine on level 5. Average occupancy is 11.5 m2 per person.

3.8.2 LightingLighting load is 3.0 kW on level 2; 1.9 kW on level 4; and 1.5 kW on level 5. Average loading 15 W/m2.

3.8.3 Other internal gainsSmall equipment loading is 3.6 kW on level 2; 2.1 kW on level 4; and 1.8 kW on level 5. Average loading 17.5 W/ m2.

3.9 Control system and control strategy for ventilation and space conditioning

3.9.1 Type of systemThe rooms are ventilated through occupant operated windows and doors. Temperature control is available form the variable refrigerant flow cooling and heating system. This system is operated by occupants who also control thermostat setting in their own space. The refrigerated system has full central control available but this feature is only used to turn the system off automatically in all rooms at 9 pm. Availability is immediately restored for the benefit of anyone working later until 12 midnight when the units are again disabled but with availability again immediately restored. Wall panel radiators are also under the control of occupants by way of manual control valves.

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3.9.2 Parameters monitoredOutdoor weather conditions such as temperature, relative humidity, dew point temperature, wind speed and direction are recorded at half hourly intervals by a weather station at the building.All energy to the refrigerated system is supplied through a dedicated sub-main and consumption has been and is recorded at half hourly intervals.Room temperatures in rooms on level 6 are measured by sensors located under the work space on desks. This is to measure as near as possible to a central body location while avoiding interference with readings by air currents.Occupancy status in level 6 rooms is recorded by means of passive infrared motion detectors. It is intended to extend this monitoring system to rooms on levels 2 and 4 by 1 July. It is also intended to monitor operation of panel radiators.A software system will also be installed shortly to monitor the operation of fancoil units and the refrigeration condensing set.

3.9.3 SensorsSee section 3.9.2 above.

3.9.4 Control strategyLaissez faire. Occupants set temperatures as they require and control ventilation by operation of windows and doors. A pilot study suggests that indoor temperatures rise from a range of 20 - 24oC in winter to 22 - 26 oC when outdoor daily mean effective temperature (ET*) is about 20 oC and then remain steady as outdoor temperatures rise further.

3.10 Costs

3.10.1 BuildingExisting building, cost not known. Estimated in order of $AU1,000 per m2 at current prices.

3.10.2 PlantThe refrigerated equipment was donated by Daikin Australia Pty Ltd. Trade value at 1997 was about $AU80,000. Cost of installation was $AU55,000 including $AU15,000 for the special submain and additional wiring needed to capture all the energy consumed by the system.

3.10.3 Control systemIncluded in cost of plant.

3.11 Monitoring programmePlease refer to item 1.1.5. To be reported more fully for the next meeting.

3.12 ConclusionsThe system has been in operation and energy consumed has been monitored since the beginning of December 1997. Energy consumption on a month by month basis is about 23 percent of the quantity per annum estimated as required for a conventional mechanical ventilation, cooling and heating system with fixed windows as estimated by hourly energy simulation software ESPII. A survey of long term satisfaction with air quality and thermal comfort was taken 3 months before the system was put into service and was repeated 9 months later. An improvement in the thermal comfort index significant to the 95% confidence level was observed. An improvement was also noted in the air quality index but this failed to reach the 95% level of confidence.The scores for both thermal comfort and air quality are better than those from 23 other office settings in a database held by the Principal Investigator.

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Tånga Falkenberg, Sweden

Tånga school in Falkenberg, Currently being retrofitted with new facades, solar chimneys for hybrid ventilation (passive stack with fan assistance) and windows with reflectors for optimum daylight

1. General information

1.1.1 Building nameTånga

1.1.2 Building typeSchool for 7th – 9th grade.

1.1.3 Principal researchersÅke Blomsterberg, J&W, Svein Ruud, SP, Mats Sandberg, KTH, Åsa Wahlström, SP.

1.1.4 Other participantsStina Holmberg, J&W, Leif Lundin, SP.

1.1.5 Principal objectivesThe main objecitve is to implement and demonstrate hybrid ventilation in a retrofit of a school.Other important objectives are:- To support the design of the hybrid ventilation system, with advanced simulations.- To design and install an advanced monitoring system, for monitoring the hybrid ventilation

system.- To performance monitor and evaluate the hybrid ventilation system, the energy use and the

indoor climate.

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1.1.6 Start date / End dateAugust 1999/August 2001

1.1.7 Report dateAugust 2001

1.1.8 References

1.1.9 Comments

2. Test site description


2.1.1 Location The school is located in Falkenberg (longitude 12° 30’ E and latitude 56° 55’ N), on the west coast of Sweden, 100 km south of Göteborg.

2.1.2 Elevation (height above sea level)10 m

2.1.3 Terrain; Site planThe school is located in a mostly residential area. The immediate surroundings are flat with some scattered trees to the south. At some distance there are some residential buildings.

2.1.4 Orientation

2.1.5 Comments

2.2 Climate information (Summary)A climate data file is available representing a typical year for the west coast of Sweden, Göteborg 1988. The weather file contains hourly values of: outdoor dry bulb temperature, outdoor humidity (kg/kg), diffuse solar and sky radiation on a horizontal surface, normal solar radiation, sky temperature. The format of the file is: i4, 3i3, 1x, f6.2, 1x, f5.4, 2(1x, f7.2), 1x, f6.2 representing year, month, day, hour, outdoor temperature, outdoor humidity, diffuse solar and sky radiation, normal solar radiation, sky temperature.

2.2.1 Air temperatureThe arverage outdoor temperature for January is 1.6 °C and for July 16.1 °C. The annual average temperature is 7.2 °C. The temperatures are averages for the period 1961-90 for Halmstad, 30 km south of Falkenberg.

2.2.2 Daylight / insolationThe global solar radiation on a horizontal plane is 161.2 kWh/m² (July), 11.3 kWh/m² (January) and 957.9 kWh/m² (annual). The solar radiation levels are averages for the period 1961-90 for Göteborg, 100 km north of Falkenberg.

2.2.3 % frequency wind speed versus wind directionAverage meteorological wind speed 3 m/s.

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2.2.4 Degree day informationYearly heating degree days 3325, based on an indoor temperature of 17 °C

2.2.5 Cloud factor

2.2.6 Relative humidity & precipitation

2.2.7 Comments

3. Building description


3.1.1 HistoryThe Tånga school was designed and built in 1968. In Sweden there is a total area in schools of 24,5 million m² (SCB 1994), out of which almost half was built between 1961 and 1975 (see table 1).Table 1 Floor areas of schools. The total area is 24.5 million m².

Almost 50 % of the schools have a floor area between 1000 m² and 4999 m² (see table 2)

Table 2 Sizes of schools.

Most of schools, 55 % of the total school area, are heated by district heating (see table 3). The second most important type of heating is oil furnace.

Table 3 Type of heating in schools.

Schools from the period 1961 - 1975 have the highest use of district heating, 166 kWh/m²year (see table 4). The most energy efficient ones is of course the newest ones.

Table 4 District heating use in schools.

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Area m² 200 - 999 1000 - 4999 5000 - 19999 20000Number 1880 3122 1289 86

Type ofheating

Oil furnace Districtheating

Electricity Otherheatingplant

Natural gas Oil andelectricity

The rest

Floor area,million m²

3,5 13,0 1,2 0,4 0,4 1,4 4,6

Year - 1940 1941 - 1960 1961 - 1975 1976 - 1980 1981 - 1985 1986kWh/m²year 160 151 166 133 123 129


Many of the schools built between 1961 and 1975 are due for renovation, one of them is the Tånga school, which will be completely retrofitted.

3.1.2 Design philosophy for IAQ and thermal comfort, energy efficiency and other issues of concern

The overall use of electricity for ventilation in building B is to be reduced by installing a demand control hybrid ventilation system combining natural (passive stack and solar chimney) and mechanical (fan assistance) driving forces, instead of the existing balanced ventilation system without heat recovery. In building A and C the existing balanced ventilation systems will be upgraded to energy efficient ones. The demand controlled hybrid ventilation system should basically be an exhaust ventilation system, where window airing is possible. In the classrooms the ventilation system should supply a basic ventilation rate during the lessons and then during breaks the ventilation can if necessary be forced. The idea is that breaks should take place regularly. CO2 and temperature sensors (integrated with the BEMS) for ventilation control are to control the ventilation. These sensors should enable the ventilation rates during the heating season to be lowered by 25 %. The users should be able to override the automatic control of the ventilation system. The users will be given user-friendly instructions of their possibilities to interact with the heating and ventilation system. The outdoor supply air is to be preheated by convectors below the windows.

There is to be no mechanical cooling system. Cooling should be achieved naturally by increasing the air flow through the passive stacks and/or window airing and night cooling controlled by the energy management system. To reduce high temperatures caused by sunshine appropriate shading devices should be installed. The daylighting level will be optimised by using, glare control, day-lighting reflectors etc. The materials (paint etc) of the interior surfaces will be chosen to optimise the indoor light climate. Energy efficient lighting devices (HF flourescent tubes combined with presence detectors) will replace the existing ones.The following special performance specifications were developed, within the MEDUCA Thermie project, for the Tånga school.

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3.1.3 Design ProcessIn order to achieve the optimal function and aesthetics of the system contacts have been frequent between the architect Christer Nordstrom (Christer Nordstrom Architects), the ventilation consult Per Magnusson (Steninge Ventilation) and the researcher within the field of HVAC Svein Ruud (SP-Swedish National Testing and Research Institute). Computer simulations of airflow rates have been made with alternative solutions regarding dimensions of ducts and design of the solar chimneys to get the maximum extent of stack ventilation. This is an important part when the stack effect providing the flow rate most of the time is below 10 Pa. The fans used are especially designed to have a high efficiency at these low differential pressures. These preliminary simulations predict the performance of the system during the worst conditions, i.e. warm weather and no wind. Future simulations will have the emphasis on simulating how the minimum damper position should be changed as a function of wind and outdoor air temperature.

3.1.4 Comments

3.2 Building geometry & materials

3.2.1 Plan<Insert diagram>

3.2.2 Elevation<include elevation for each facade where applicable>

3.2.3 Building formThe school consists of four different building:A - with auditorium, dining hall, kitchen, offices. The building has two stories, is almost rectangular and has a flat roof.

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B - with mainly classrooms. The building has two stories, is E-shaped and has a flat roof.C - with mainly workshops. The building has two stories, is rectangular and has a flat roof.D with a gym.

Buildings A, B and C are being retrofitted. The hybrid ventilation system will be installed in building B.

3.2.4 VolumeHeated volumes:Building A, 8628 m³Building B, 12031 m³Building C, 3672 m³

3.2.5 Floor area & materialsThe gross floor areas:Building A, 1363 m²Building B, 3672 m²Building C, 1096 m²

1including frame and casement.

Building A Wall 6 cm brick + 12 cm mineral wool + 6 cm brickRoof 25 cm loose fill insulation + 13 cm mineral wool + 2 cm woodGlazing Double paneFloor 2 cm mineral wool + 10 cm concrete

Building B Wall 6 cm brick + 12 cm mineral wool + 6 cm brickRoof 25 cm loose fill insulation + 13 cm mineral wool + 2 cm woodGlazing Double pane, one of the three wings is retrofitted with low enenrgy

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BuildingA

U-value Area,m²

Wall 0.34 1141Roof 0.12 970Glaz-ing1

1.90 273

Floor 0.34 970BuildingB

U-value Area,m²


1.76 435

Floor 0.34 1836BuildingC

U-value Area,m²


1.90 106

Floor 0.34 548


windows (U-value 1 W/m²K)Floor 2 cm mineral wool + 10 cm concrete

Building C Wall 6 cm brick + 12 cm mineral wool + 6 cm brickRoof 25 cm loose fill insulation + 13 cm mineral wool + 2 cm woodGlazing Double paneFloor 2 cm mineral wool + 10 cm concrete

3.2.6 Ceiling heightThe room height is 3.3 m.

3.2.7 Facades (external walls)See chapter 3.2.5 Floor materials

3.2.8 WindowsSee chapter 3.2.5 Floor materials

3.2.9 External doors or hatches<Total area of external doors or hatches for each wall or ceiling. Describe door/hatch type>

3.2.10 Number, volume and layout of rooms18 classrooms will be ventilated by the hybrid ventilation system. Each classroom has a floor area of 60 m² and a volume of 187 m³.

3.2.11 Attic, basement, crawlspace<description and degree of interaction with conditioned space should be specified, U-values>

3.2.12 Interior walls, including moveable partitionsMost interior walls are of 12 cm brick.

3.2.13 Interior doors and devices<also mention presence of flow openings above or below doors>

3.2.14 Stairwells<Number and sizes of stairwells, and venting arrangement>

3.2.15 Service risers<Number and sizes of elevator shafts, including size of opening at top of shaft><Number and sizes of rubbish chutes, including size of opening at top of shaft>

3.2.16 Comments

3.3 Air leakage data (type, location and crack length for each component)<State airtightness (blower-door pressure test, ACH@50Pa) for whole building, if it has been measured>

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3.3.1 Doors

3.3.2 Windows

3.3.3 Ventilation openings & stacks

3.3.4 Chimneys & flues

3.3.5 Communicating walls, such as cavity walls

3.3.6 Structural joints: sole-plate, ceilings, corners, skirting boards, vapour and air barrier treatments

3.3.7 Service routes: plumbing outlets, drains, electrical outlets, etc.

3.3.8 Other air leakage zones such as stairwells & service risers

3.3.9 Background leakage

3.3.10 Neutral pressure level

3.3.11 Comments

3.4 Wind pressure coefficients

3.5 Space heatingEnergy for space and hot water heating is provided for by the district heating system of Falkenberg. Every room is heated by radiators or convectors with thermostatic valves.

3.6 Ventilation

3.6.1 Ventilation principleThe main principle of ventilation of building B school is passive stack ventilation. When stack effects don’t provide a sufficient differential pressure, assisting fans will maintain it at a sufficient level. In the Tånga school the outdoor air is distributed to the rooms through several air intakes below the windows in the exterior walls into a stub duct from where it is distributed to the room. The outdoor air is preheated by convectors under the stub duct. This should bring about mixing ventilation in the classrooms. The extract air is evacuated through air terminal devices below the ceiling on the opposite side of the room into vertical ventilation ducts. Local dampers are mounted both in the air intakes and in the exhaust duct of each room to allow individual control of the flow rate. To prevent air from going backward through the duct system all of the classrooms have their air intakes against the predominant wind direction.

To increase the stack effects, 6 m high solar chimneys have been installed on the roof with assisting exhaust fans and central dampers mounted in parallel. In addition to extending the length of the exhaust ducts, the solar chimneys consist of a flat plate solar air collector that heats the air in the chimney and increases the stack effect the last 6 m of the exhaust ducts. There are in total three solar chimneys, each one serving a separate part of the building. It is desirable to get equal stack effects on both floors and when needed having the exhaust fans working simultaneously. To achieve this the design is to reduce the cross-section area of the exhaust ducts from the first floor. Another option was to make the solar chimneys serving the second floor 3 m higher than those serving the first floor as to compensate for the total height difference.

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Tånga school in Falkenberg. The figure shows the principle of the new hybrid ventilation system wiht supply air through convectors in the fasada and exhaust through the passive stack.

Building A and C is ventilated by an efficient balanced ventilation system incorporating air-to-air heat recovery.

3.6.2 ComponentsLow pressure vents in the facade and low pressure exhaust air terminal devices.<System schematic, if possible><Provide pressure drops or flow-exponent wherever possible>

3.6.2.1 Fresh air inletsThe outdoor air is distributed to the rooms through air inlets below the windows (three per classroom) in the exterior walls into a stub duct from where it is distributed to the room. The outdoor air is preheated by convectors under the stub duct. This provides mixing ventilation in the classrooms.

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Picture: The window sill in a classroom, where the outdoor air enters and is preheated by a convector. Notice the new upper window for bringing daylight to the inner parts of the room.. Between the upper and lower window reflecting shelves will be installed.

3.6.2.2 FansThe fan is frequency controlled.<size, flow capacity where available, airlfow k-factor when fan is switched off. Blade type. Type of speed control>

3.6.2.3 Heat recoveryThe requirements for energy conservation should for the building as a whole meet the national requirements. For the demand controlled hybrid ventilation system in building B this means that the mean energy consumption should be 50% lower than for a constant air volume (CAV) system without heat recovery, and where the air flow rates meet the national requirement during occupancy. As the actual system do not incorporate any means for heat recovery of the exhaust air, energy conservation for the ventilation system is instead achieved by using an advanced variable air volume (VAV) control system. It should also be noted that for a large part of the year there is no heat demand in a classroom when it is in use and therefore there is no need for heat recovery during periods of high air flow rates.

3.6.2.4 FiltrationAs the school is situated in a quite clean environment it has been considered acceptable to use no filters to decrease the pressure drop through the air intakes. Louvers and mosquito net are however used to prevent rain and snow as well as insects and larger particles as leafs to enter the duct. The air intakes and the stub duct are easily accessible and can be cleaned by hand.

3.6.2.5 Ducts<tightness, size, insulation, type and location>

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3.6.2.6 Room supply & extract devicesSee 3.6.2.1 and 3.6.1<Location & type of air supply inlets & outlets>

3.6.2.7 Air exhaust outletsSee 3.6.1<e.g. ventilation stacks, wind-augmentation>

3.6.3 Frequency of operation, duration of operating cycle

3.6.4 Balancing report<for systems that move air, if available>

3.6.5 Ventilation rate (outdoor airflow supplied by system)The national requirements for minimum ventilation air flow rates is 7 l/s/person during periodes of occupancy and 0.35 l/s/m² during periodes of non-occupancy. The design air flow rate for the actual hybrid ventilation system is however only 4.5 l/s/person based on maximum occupancy in the classrooms. The arguments for this design value is that there seldom is maximum occupancy, children have lower metabolism than adults and that one for shorter periods of time can allow a higher CO2 level than 1000 ppm. However if the hybrid ventilation system for some reason does not give an acceptable indoor air quality it should always be possible to manually change to a third CAV operation mode with the fans running to ensure an airflow rate of 7 l/s/person based on maximum occupancy in the whole building.

3.6.6 Any recirculation between rooms due to HVAC system

3.6.7 Space coolingMost windows can be opened. Night cooling is also possible.

3.6.8 Comments

3.7 Construction materials, properties and techniquesThe buildings have walls of brick construction and floors of concrete.<Here one should describe the structure of the envelope, paying attention to materials, jointing methods and the effects on communicating spaces. Specify for each envelope component: absorption transmission and emissivity properties of the materials>

3.8 Internal loads

3.8.1 Pattern of occupancyThe buildings are basically occupied 195 weekdays/year between 7.00 and 16.00. Typically classrooms are occupied by 25 pupils and on teacher i.e. 2.3 m²/person. All in all there is 413 pupils and a staff of 60 persons. The internal gains from persons and PC’s for a classroom have been determined to be 1.95 kW between 7.00 and 16.00 for weekdays.

3.8.2 LightingDaylighting is improved in three classrooms in building B with upper windows and internal daylight reflectors, and improved existing skylights. Energy efficient lighting devices (installed electric power in classrooms 13 W/m², in corridors 8 W/m²) i. e. HF fluorescent tubes are installed in building A, B and C. The artificial lighting is automatically controlled by presence detectors i.e. switched off.

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3.8.3 Other internal gainsThe internal gains from the new HF fluorescent tubes have been estimated to be 12 W/m² weekdays between 7.00 and 16.00 for week 1 to 14 and week 41 to 52.


3.9.1 Type of systemThe BEMS operates in a Windows environment. The system communicates by analogue or digital telephone networks with respect to data transfer and alarm handling. The system allows logging in from external computers. The file format of monitored/measured data is standardised to enable file transfer of data to external environments. The system enables operation from both external terminals and the subcentrals in addition to the monitoring central. The system monitors the energy (district heating and electricity) use in detail (separately space heating, hot water, electricity for ventilation and lighting, the building is divided into three different parts). Temperature, relative humidity and CO2 in classrooms are also monitored.

The ventilation control system at the Tånga school is a combination of individual and central control. The space heating is mainly controlled by the outdoor temperature i.e. the forward temperature is controlled by the outdoor temperature. Each radiator and convector is also equipped with a thermostatic valve.

3.9.2 Parameters monitoredCO2 content of the indoor air, time, indoor, outdoor and solar chimney temperature.

3.9.3 Sensors<Also mention location for all sensors, even external sensors>

3.9.4 Control strategy & internal design conditionsAn outdoor air temperature sensor and a CO2 sensor in each room control the local dampers. At a CO2 level of 1000 ppm or less the local dampers are set to a minimum position. This minimum position can be varied as a function of the difference between the temperature in the solar chimney and the outside, and the wind velocity. At extremely low outdoor temperatures and/or high wind velocities the air flow rate is therefore automatically limited to prevent excessive energy consumption and problems with dry indoor air. If the CO2 level exceed 1000 ppm this is indicated by a signal lamp. At CO2 levels above 1500 ppm the local dampers open 100 %. The teacher can however always override the local control system and manually change the position of the local dampers. In summertime the stack effect decreases. Below a certain temperature difference between the outdoor air and the air in the solar chimney the stack effect is no longer sufficient to maintain the design airflow rates. The central dampers are then closed and the exhaust fan simultaneously started. To avoid a high frequency of starting and stopping of the fan the dampers are opened and the fan is stopped at a somewhat higher temperature difference. When running, the exhaust fan speed is controlled by the difference between the temperature in the solar chimney and outside. The exhaust fan increases the pressure difference continuously as the temperature difference decreases. The ventilating system requires window opening when the CO2 level in the indoor air exceeds 1000 ppm for a longer time or if the indoor temperature rises to an uncomfortable level in the summertime. In summertime the stack effect can also be utilised for night cooling of the building. At a centrally located control panel the personnel can if necessary override both the local and the central control strategy and set an fan controlled design air flow rate of 7 l/s per person in the whole building.An expected result is to be able to show that energy consumption of fan work could be reduced to an extremely low level by using the existing stack effect and due to the design of ductwork and

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the controlling of the fan. Studies of the expected stack effect show that the temperature breaking point between stack ventilation and the fan assisted ventilation will be at an outdoor temperature of approximately 8 °C (7 °C for cloudy conditions and 9 °C for sunny conditions). This means that the stack effect should be sufficient in the winter months, early spring and late autumn.

3.10 Costs<Preferably use EURO €. Pay special attention to evaluation of extra costs. Also note typical costs /m2 for a typical building of same type in your country, with conventional HVAC system>

3.10.1 BuildingThe investment cost is 188 kECU for building B.

3.10.2 PlantThe ventilation investment cost is 218 kECU for building B.The heating investment cost is 95 kECU for building B.

3.10.3 Control systemThe investment cost is 36 kECU for building B.

3.11 Monitoring programme

3.11.1 Measurement ObjectivesThe objective is to evaluate the hybrid ventilation system with respect to ventilation (air flow rates, air change efficiency), thermal comfort, use of electricity for ventilation and energy use for space heating.

3.11.1.1 Measurement Objective 1 and list of questions to be answered

3.11.1.2 Measurement Objective n and list of questions to be answered

3.11.2 Parameters to be measured, Measurement plan

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<State what parameters are measured (please refer to parlist.doc, monsched.doc) and where and when, and any results or observations that have been gathered so far>

3.11.3 Parameters analysisThe ventilation for different operating conditions (mainly different outdoor climates, but also different internal loads and user behaviour) will be determined. This will carried out using tracer gas techniques and calculations using multi-cell air flow models e.g. COMIS in order to determine the variation in total ventilation for a year in a classroom. During the design detailed calculations of the performance of the hybrid ventilation system with regard to the air flow rate as a function of temperature, wind and solar heat were carried out. These measurements have to be supplemented with accurate measurements of wind pressures on the facades. Wind pressures are very important inputs to the above mentioned calculations and enable a determination of the sensitivity to wind of the hybrid ventilation system. Windtunnel studies of a scale model of the building will also be carried out. The passive stack is in principle wind neutral.

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Monitoring Monitoring period: 99-12-01 to 01-08-31Instrumentation description: The monitoring system incl. sensors areintegrated with the BEMS according to specially developed MEDUCAtechnical specifications.

Measured quantity No. of sensors Frequency of datareporting (during intensiveperiods every 15 minutescan be used)

Measurementuncertainty

Cold water use 4 5 %Energy use for space andtapwater heating

6 Every hour 5 %

Use of electricity(ventilation, lighting,pumps, wall outlets,miscellaneous)

20 Every hour 2 %

Air temperature inclassrooms and ducts

70 Every hour 0.5 K

Relative humidity inclassrooms in bldg B2

6 Every hour 5 %

CO2 in classrooms 30 Every hour 100 ppmAir velocity in ducts bldgB2

6 Every hour 0.1 m/s

Air flow direction inducts from bldg B2

6 Every hour

Local and central damperopening (six classroomsin bldg B2)

24 Every hour 5 degrees

Operational timesmanual/auto forventilation systems inclassrooms in bldg B2

6 Every hour 5 min

Outdoor air temperature 1 Every hour 0.5 KGlobal horizontal solarradiation

1 Every hour 5 %

Relative humidity,outside

1 Every hour 5 %

Wind speed 1 Every hour 0.5 m/sWind direction 1 Every hour 5 degrees


The thermal comfort will determined as a function of the hybrid ventilation system using short term measurements for different climatic conditions. The results will be compared with the performance specifications (see chapter 3.1.2).

The indoor air quality will be determined using short term measurements for different climatic conditions, mainly CO2. The results will be compared with the performance specifications (see chapter 3.1.2).

The energy use for space heating for a year will be determined in detail based on monitored values from the BEMS. The importance of ventilation to the energy use will be determined by calculations of air flows and energy use based on measured values. The energy will be calculated with a dynamic simulation program DEROB-LTH. Comparisons with balanced ventilation with heat recovery will be performed and with the original predictions with DEROB-LTH.

The use of electricity will be compared with traditional ventilation systems and the performance specifications (see chapter 3.1.2).

3.12 Conclusions<Mention any conclusions so far gained from the building, if any>

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Bang & OlufsenStruer, Denmark

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1. General information

1.1.1 Building nameBang & Olufsen

1.1.2 Building typeOffice

1.1.3 Principal researchersHenrik Brohus and Christian Frier, Aalborg UniversityOle Juhl Hendriksen, Esbensen Consulting Engineers

1.1.4 Other participantsJan Stie, TACVagn Kristensen and Christian Pedersen, Bang & Olufsen Facilities Management

1.1.5 Principal objectivesMonitoring of thermal and atmospheric indoor climate, ventilation capacity and energy consumption with the objective to analyse the performance of the building and to establish boundary conditions for testing purposes.

1.1.6 Start date / End date28.02.2000 / 31.03.2001

1.1.7 Report datePreliminary reports during the monitoring period and a final report in 2001.

1.1.8 References

1.1.9 Comments

2. Test site description


2.1.1 Location 56.42º N, 8.58º E

2.1.2 Elevation (height above sea level)12 m

2.1.3 Terrain; Site planOpen country, see appended Site Plan

2.1.4 OrientationMain facades have an orientation of 0º and 180º

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2.1.5 Comments

2.2 Climate information (Summary)Weather data from Design Reference Year is available (CPH.DRY). Monthly average values of outdoor climate parameters are in Appendix 1 Weather Data.

2.2.1 Air temperatureSee table of weather data

2.2.2 Daylight / insolationSee table of weather data

2.2.3 % frequency wind speed versus wind directionN/A

2.2.4 Degree day informationSee table of weather data

2.2.5 Cloud factorN/A

2.2.6 Relative humidity & precipitationSee table of weather data

2.2.7 Comments

3. Building description


3.1.1 HistoryNew office building completed in 1998

3.1.2 Design philosophy for IAQ and thermal comfort, energy efficiency and other issues of concern

Bang & Olufsen required an office building of high quality and a minimum of technical installations, which should be simple and hidden.The office layout is based on an open plan principle.The north facade, which is shown at the front page photo, is fully glazed with openings in the horizontal divisions serving as inlet for natural ventilation. The south facade has a moderate window area serving as supply for daylight and has user controlled windows, which are automatically controlled during night time for cooling of the building. Air is extracted through special designed cowls on top of the roof, which also has integrated fans for assistance, when the natural driving forces are insufficientThe air distribution principle is displacement ventilation.

3.1.3 Design ProcessThe building is specifically designed for natural ventilation. In the design stage for the ventilation the architects and engineers took into account both the thermally generated pressures as well as the wind induced pressures. The design team, the client and the main contractor had a thorough co-operation to optimise the initial costs of the building.

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3.1.4 Comments

3.2 Building geometry & materials

3.2.1 PlanSee appendix 2, Site Plan.

3.2.2 ElevationN/A at the the moment.

3.2.3 Building formA quite narrow building, which is 8 meter wide and has a height of 12 m and a flat roof.

3.2.4 Volume<Total volume for building (i.e. including structure)><Effective volume if available, i.e useful volume, excluding building services etc., not imperative>

3.2.5 Floor area & materialsFree exposed concrete decks.1.520 m2 of gross floor area.<U-values, and ideally description of the thickness & material in each layer, for energy use calculations. U-values to special spaces such as attic, basement, crawlspace>

3.2.6 Ceiling heightThe net ceiling height is 3.1 meter and the gross height is 3.4 meter. Depth of floor is 7.5 meter.

3.2.7 Facades (external walls)<facade areas. include U-values, and ideally description of the thickness & material in each layer, for energy use calculations>

3.2.8 Windows<Total area of windows for each wall; Describe window type; U-values. External shading type, geometry and description of automated shading control-system, if any>

3.2.9 External doors or hatches<Total area of external doors or hatches for each wall or ceiling. Describe door/hatch type>

3.2.10 Number, volume and layout of rooms<name rooms and function where applicable>

3.2.11 Attic, basement, crawlspace<description and degree of interaction with conditioned space should be specified, U-values>

3.2.12 Interior walls, including moveable partitions<specify sizes, areas, U-values (thickness of layers and materials used)>

3.2.13 Interior doors and devices<also mention presence of flow openings above or below doors>

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3.2.14 StairwellsTwo central stairwells serving as extracts for the hybrid ventilation system.

3.2.15 Service risersOnly service risers for piping, wiring and additional mechanical extracts from toilets and copying rooms.

3.2.16 Comments

3.3 Air leakage data (type, location and crack length for each component)N/A

3.3.1 Doors

3.3.2 Windows

3.3.3 Ventilation openings & stacks

3.3.4 Chimneys & flues

3.3.5 Communicating walls, such as cavity walls

3.3.6 Structural joints: sole-plate, ceilings, corners, skirting boards, vapour and air barrier treatments

3.3.7 Service routes: plumbing outlets, drains, electrical outlets, etc.

3.3.8 Other air leakage zones such as stairwells & service risers

3.3.9 Background leakage

3.3.10 Neutral pressure level

3.3.11 Comments

3.4 Wind pressure coefficientsN/A

3.5 Space heatingCHP plant with natural gas engine. Radiators at south facade for space heating. Ribbed heat pipes at north facade for heating of inlet air.

3.6 Ventilation

3.6.1 Ventilation principleStack- and wind driven with fan assistance. Air is supplied via automatic windows in the north facade using displacement ventilation. Extract through stairwells with back-up fans in cowls. Windows in south facade are used for supplementary ventilation during summertime resulting in cross-flow ventilation.

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3.6.2 Components

Visualisation of air flow principle. Courtesy of Birch & Krogboe A/S, Consultants and Planners.

3.6.2.1 Fresh air inletsInlet windows are located in the horizontal division of each floor.

3.6.2.2 FansTwo axial fans with a diameter of 1000 mm in each cowl. Three blade propeller with a pitch angle of 15º. Design air flow rate of xx/yy m3/s,. the fans are frequency controlled from 0-900 rpm.

3.6.2.3 Heat recoveryNone

3.6.2.4 FiltrationNone

3.6.2.5 DuctsNone

3.6.2.6 Room supply & extract devicesInlet grilles located in floor. Extract via doors to stairwell

3.6.2.7 Air exhaust outletsSpecial designed roof cowls for improvement of wind pressure

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3.6.3 Frequency of operation, duration of operating cycleHybrid ventilation is active from 6 am to 6 pm durimg working days if the set value of CO2 is exceeded (600 PPM). Rain and strong wind overrules the control system.

3.6.4 Balancing reportN/A

3.6.5 Ventilation rate (outdoor airflow supplied by system)

3.6.6 Any recirculation between rooms due to HVAC systemNone

3.6.7 Space coolingThe building structure, especially free exposed concrete slabs, are used as cooling storage during night-time in the summer period.

3.6.8 Comments

3.7 Construction materials, properties and techniquesConcrete slabs and pillars. The south facade and end walls has an inner beam of concrete and bricks on the outside. The north facade is fully glazed with a structure based on steel frames.

3.8 Internal loads

3.8.1 Pattern of occupancy8 am to 5 pm. 27 occupants at each floor corresponding to 10.7 m2 per occupant and approximately 9 W/m2

3.8.2 LightingManual switch. Approximately 10 W/m2

3.8.3 Other internal gainsOne PC per occupant. Approximately 14 W/m2.


3.9.1 Type of system

3.9.2 Parameters monitoredIndoor climate control parameters are dry bulb temperature and CO2 level. The hybrid ventilation system is also controlled with respect to outdoor climate parameters such as ambient temperature, rain and strong wind.

3.9.3 SensorsRoom temperature sensors are located in a height of approximately 1.6 meter. CO2 sensors are located in a height of 2.2 meter. External sensors are located on roof.

3.9.4 Control strategy & internal design conditionsSet value for room temperature is approximately 21ºC and set value for inlet air is 19ºC.

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3.10 CostsN/A at the moment.

3.10.1 Building

3.10.2 Plant

3.10.3 Control system

3.11 Monitoring programme

3.11.1 Measurement ObjectivesSee file: ParList DK Bang & Olufsen.doc

3.11.1.1 Measurement Objective 1 and list of questions to be answered

3.11.1.2 Measurement Objective n and list of questions to be answered

3.11.2 Parameters to be measured, Measurement plan< See file: ParList DK Bang & Olufsen.doc and monshed DK Bang & Olufsen.doc.

3.11.3 Parameters analysisDuration curves for temperatures and CO2 concentrations, PMV, PD and analysis of energy consumption.

3.12 ConclusionsN/A at the moment.

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