Passivhaus offices energy

monitoring, analysis and lessons

learnt

SustainCo Study Tour 1 2nd July 2014

1st UK Certified Passivhaus Offices - Canolfan Hyddgen

Project Drivers

Applying Passivhaus concept & principles in Wales/UK

Design details & construction method

Energy Monitoring & Post occupancy evaluation

Challenges to Passivhaus construction in UK

Our Architectural philosophy is always to reduce energy consumption & associated CO2 emissions first, and then apply appropriate renewable technology to achieve carbon neutrality where viable domestic & non domestic

architecture & passivhaus consultancy passivhaus construction & components

john@jpwconstruction.co.uk

Low energy = Low carbon & Low fuel bills!

Powys County Council - Carbon Management Programme

Targets Co2 - reduction of 30% by 2012 and 50% by 2017

Potential cumulative carbon saving of 39,000t and a financial

saving of 7.8m over the next 5 years via energy efficiency

Dyfi Valley Path Finder (DVPF) Canolfan Hyddgen

WAG/PCC Funded Scheme

Property Rationalisation

Reduce energy consumption,

fuel bills & overheads

Maximise revenue through

design and management

Strategy for multiple tenancy

& Community use

Reduce Carbon Footprint

Client requirement

PHI Certification & BREEAM Excellent Certification (First time In UK that both standards have been applied simultaneously)

BREEAM Principles - A range of sustainable issues & targets

Highest score at time in Wales

BREEAM 2009 Award for Offices

BREEAM Offices Excellent 84.43%

Management 100.00%

Health & Well Being 84.62%

Energy 72.2%

Transport 53.3%

Water 100.00%

Materials 83.33%

Land Use & Ecology 90.00%

Pollution 93.33%

Note: Part L2 BRUKL reports low energy performance (72.2%) via a Fabric First Passivhaus approach.

EPC via Part L2 = B

EPC in reality using Passivhaus = A+

The Specific Climatic conditions

Specific PH solutions must be adapted for each

territory and climate under consideration.

Differences in solar gain & thermal mass being

the main Reason. In other regions, other energy

services, like cooling or dehumidification, could

be of greater importance than heating.

Passive House solution can be soundly applied

independent of the geographic and climatic

circumstances with careful planning.

Design

Detail

Elements must be combined & considered in detail to

produce a holistic outcome depending upon :

Air tightness

Canolfan Hyddgen non domestic

n50 = 0.249 -1 @ 50Pa (PHI requirement is 0.6)

Q50 = 0.37 m3 /(h.m2 ) @ 50Pa (UK measurement)

EST Advance Practice requirement is q50 = 1 m3 /(h.m2 ) @ 50Pa

UK best practice for mechanically ventilated q50 = 3 m3 /(h.m2 ) @ 50Pa

UK General non domestic & domestic q50 = 10 m3 /(h.m2 ) @ 50Pa

L2A UK Assumed air leakage provided TER is achieved using

NCM (under 500m2) q50=15 m3 /(h.m2 ) @ 50Pa

De-Centralised & Centralised Ventilation System

Electrical efficiency and renewable generation

PCC Costs 1.2 m

Program: project initiated in August 2007 WAG grant of 750k

expended during financial year 2007/08

Pathfinder - 410m2

Basic building 1537/m2

incl PV's & green roof 1721/m2

incl PV's & green roof & canopy 1784/m2

BRE & Faithful & Gould report, dated Sept 2008, stated

benchmark

Secondary school of 3116m2 to meet Part L2 Building Regs cost

1711m2

Addition to meet BREEAM Excellent 1789 to 1858m2

Predicted & Actual Performance

Design Tools

PHPP 2007 was used as the primary energy calculation tool and

the additional sheets to calculate non domestic internal heat gains

and utilisation proved valuable.

TAS software was also used for level 5 dynamic simulation of the

building. This enabled detailed analysis of inter zone air movement

through the building and also provided values for UK Part L2

compliance in particular summertime overheating risk.

Ecotect & Radiance for day lighting analysis.

Space Heating & Primary Energy

The resulting predicted values 2007 were

Space heating 14.8 kWh/m2/a,

Electricity approx 27000kWh/a

PV generation of 5250kWh/a

Actual values from (8/10/09 08/10/10) after building had been commissioned and allowed to dry out for 18 months are

Space heating (measured over 12 months) = 14.8 kWh/m2/a,

Electricity (measured over 11 months) = 61 kWh/m2/a

(24,400kWh/a)

PV generation of 5987kWh/a.

UK Carbon Emission Compliance

Existing EPC Rating

Office Building only

(No Renewables) 33 B

7kW (51m2) PV on Offices 16 A

Potential further de carbonisation of development

7kW (51m2) PV on Offices

Plus 14.43kW (100m2) PV

On neighbouring School roof 0 A+

7kW (51m2) PV on offices

Plus 20kW Wind Turbine

Off site Generation -65 A+

Cost Neutral Compliance

A EPC Rating Certified Passivhaus with 7kW PV

Annual Fuel Bill

Space Heating = 126.62 (0.947 T/CO2/a)

Electricity (inc DHW) = 2177.19 (13.8 T/CO2/a)

= 2303.80

Potential FIT

PV income = 2454.67

Summary of lessons learnt from POE

This duplication of calculation PHPP & TAS Dynamic

Simulation added to the design costs

but

Interesting comparisons emerged and a commitment from the

client and design team to monitor performance and learn from

the outcomes was established.

ICT , Ventilation flow rates (10l/s or 8l/s or 5l/s) & RH v C02 V

thermal comfort posed biggest specification & Commissioning

challenges

UBTs Soft Landings now being written into PCC procurement process

Air quality & Occupant perception

Filter left for 1 year in one

unit as an experiment (3-6

months being the advised

frequency for changing).

External intake filter (top) has

experienced blackening from

localised wood stove/coal fire

smoke particles

The internal extract filter

(bottom) has effectively

filtered dust from the building

The new clean filter (Centre)

is for comparison.

Boiler sizing

Simple robust aux heating

system - Broag Avanta plus Gas

boiler 9-24kW & LST radiators

400X12w/m2 = 4.8kW Load

However sizing is important

M&E contractor reluctant to fit a

smaller boiler

Modulation issues particularly

In Spring & Autumn

Ignition board faliure & repair

Automatic or standard summer bypass ?

Comfort levels for occupants in winter have

been very good positive feedback.

The change over from Welsh winter to spring

and autumn to winter - 4 seasons in one day!

Automatic summer bypass to ease transition?

Currently the HX box is changed to summer

bypass box manually. Modifications to this

arrangement (Management system or technical

solution ) are recommended as part of the

learning outcomes from the first stage of POE

analysis.

Weather Data Solar Gain

Global Radiation August

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31

August

kW

h/m

2 p

er d

ay

Canolfan Hyddgen 2009 Cardiff DSY Machynlleth TAS

PHPP Average Canolfan Hyddgen average Machynlleth TAS Avereage

Cardiff DSY Average

Global Radiation December

0.00

0.50

1.00

1.50

2.00

2.50

3.00

1 3 5 7 9 11

13

15

17

19

21

23

25

27

29

31

December

kW

h/m

2/d

ayayy

Canolfan Hyddgen 2009 Canolfan Hyddgen Avereage

Cardiffy TRY Cardiff TRY Average

"Machynlleth TAS Machynlleth TAS Average

PHPP Average

December Average Daily Temperatures

-5.00

0.00

5.00

10.00

15.00

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31

December

De

gre

es

C

Canolfan Hyddgen Cardiff TRY Machynlleth TAS

PHPP Average Canolfan Hyddgen Average Machynlleth TAS Average

CAT Average 2009

August Average Daily Temperatures

10.00

15.00

20.00

25.00

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31

August

De

gre

es

c

Canolfan Hyddgen Cardiff DSY Machynlleth TAS

Canolfan Hyddgen average Machynlleth TAS Average PHPP Average

CAT Average 2009

Solar Gain Winter & Summer

Summer Bypass in Position

Ventilation System @ Level 3

purging rooms and thermal mass

IT suites experience higher

internal gains and take longer to

purge & Cool

Passivhaus Classification Rebrand

A new calculation method for primary energy demand that also

considers energy production via renewable energy systems

and energy storage systems. The intent is to incorporate and

encourage a robust assessment of the environmental impacts

of these systems. A new Primary Renewable Energy (PRE)

factor has been produced that allows for a more rational way to

express a buildings energy balance and climate impact.

A building that produces an energy surplus in summer doesnt necessarily have a good energy balance. Photovoltaic systems

typically yield very little energy in winter, which is exactly when

the most energy for heating is used. Therefore, the calculation

only works when the energy demand itself is also very low.

Dr Wolfgang Feist Passivhaus Institute

The Passivhaus Institute introduces new categories and additional criteria to

ensure it meets EU mandates for all new developments to be Nearly Zero Energy Buildings in 2021

Building only or some Renewables Energy Balance EPC

Passivhaus Energy Space + 30 Kwh/m2/a ?

Conservation Building Operation +120 Kwh/m2/a ?

'nearly Passivhaus buildings'

Passivhaus Classic Space + 15 Kwh/m2/a A?

Operational +120 Kwh/m2/a A?

Potential further energy balancing of a development

Passivhaus Plus Space +/- Kwh/m2/a A/A+?

Striving to meet NZEB Operational +/- Kwh/m2/a A/A+?

Passivhaus Premium Space - ? Kwh/m2/a A++?

Energy Positive Building Operational - ? Kwh/m2/a A++?

The present collection of slides was assembled for participants of SustainCo/Building Regs & Study

Tour 1: Machynlleth. This file or any printed copy of this file is for information purposes only and intended only for the personal use of the participants of this event. The transferral of this file to a third party or the right to publish it in any form is excluded. The contents are the intellectual property of JPW Construction. In particular the use of individual contents (slides) is not permitted without the express permission of JPW Construction