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Technical Focus

The Clivet Enhanced Hydronic System Evolving central plant design to the best life-cycle saving Application for multi-level office building

TF14I001GB-02 Technical Focus · The Clivet Enhanced Hydronic System 2

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FOREWORD 3

THE CLIVEY ENHANCED HYDRONIC SYSTEM 3

TECHNOLOGIES AND BENEFITS 4

APPLICATION FOR MULTI-LEVEL OFFICE BUILDING 6

SYSTEM DESIGN 8

ENERGY ANALYSIS 10

CONCLUSIONS 31

APPENDIX 32

Effect of climate 13

Effect of cooling technology 27

Effect of heat recovery technology 25

Effect of heating technology 29

TABLE OF CONTENTS

TF14I001GB-02 3 Technical Focus · The Clivet Enhanced Hydronic System

FOREWORD

Keeping optimal comfort conditions within buildings can result in significant saving on capital and operating cost, able to affect the most accurate business plan.

This behaviour applies worldwide, in both new constructions and renovations; it is even enhanced in the commercial sector, due to the higher range of challenging constraints such as high space loads, simultaneous cooling and heating, outdoor air management and domestic hot water, if any.

Central plants are probably the most popular HVAC design in this sector: they can further benefit from many enhanced technologies and solutions, already available from the Industry but applied much less than they would, providing excellence in performance, easier design, energy saving and competitive overall cost year-round.

For these reasons, the Enhanced Hydronic System from Clivet is here introduced, looking at its applications and exploring the benefits over traditional equipment.

THE CLIVET ENHANCED HYDRONIC SYSTEM

Commercial buildings are specialised by function: shopping centres, offices, hotels and restaurants, entertainment, hospitals provide different services and have individual comfort requirements, affecting all together the overall energy efficiency.

The Clivet Enhanced Hydronic System is the standardized, industrial comfort solution able to fit to individual requirements thanks to its effective modular design.

Core of the System is ZEPHIR3, the complete packaged Primary Air supply System with thermodynamic energy recovery.

Primary air today is crucial: demanding Indoor Air Quality (IAQ) standards, virtually sealed building and reduced heat gain/loss through the envelope make this function the major load.

As very often this is higher than space loads, it easily becomes one of the largest operational costs at all.

ZEPHIR3 provides all Primary Air functions in a single stand-alone System: supply and exhaust air management with thermodynamic energy recovery, full outdoor air operation, total humidity and automatic temperature control through its in-built reverse cycle refrigeration circuit. It is:

cost effective, as it gets rid of all pipework to traditional Outdoor Air AHU’s (inclusive of pumps, valves, water tanks, controls) and at the same time reduce both size and cost of central cooling and heating stations (liquid chillers, boilers and relevant auxiliary equipment)

energy efficient, as extract air is the heat source: this results in twice as much efficiency as usual refrigeration circuit do. Furthermore, as an electric heat pump it does not use any fossil fuel, for superior environmental performance

effective on IAQ, due to electronic filters able to keep 99% pure air and relentless extract to eliminate indoor pollutants.

Its totally independent operation allows much more flexible system design, as never done before with central bespoke equipment.

Fig. 1: The Clivet Enhanced Hydronic System is the effective solution in most commercial applications, such as Office buildings, Shopping centres, Hotels and Hospitals.

Fig. 2: ZEPHIR3 encloses all functions for stand-alone operation. Every single unit is full factory tested, thus on-site commissioning is much shorter than usual.

PIPEWORK

CHILLED WATER HOT WATER

Office

Open

Space

MeetingRooms

TERMINAL UNITS


Fig. 3: The SPINChiller range pioneered the modular Scroll technology, providing at a time sustainable ESEER and compact size.

Chilled water and/or hot water for space loads and domestic hot water, if any, are provided by SPINCHILLER through the widest and more flexible range on the market:

sustainable, as its modular Scroll technology results in superior seasonal efficiency at the most competitive overall cost, more effective than other equipment even using VFD compressors

versatile, as the many functions available fit in any application and climate: chiller, freecooling chiller, heat pump, multifunction heat pump for 2-pipe, 4-pipe and DHW management. Different energy versions match with individual capital cost dynamics. Both air source and water source are available.

reliable, thanks to the in-built automatic functions such as Hydropack water circulation, free heat recovery, low / high ambient operation

ELFO Space fan coil units are an integral part of the System, fitting with both energy challenges and IAQ issues:

energy efficient, as DC brushless fan motors save 60% energy over traditional units

quiet, to keep optimal comfort on the acoustic side as well

flexible, being available in both cased and uncased versions, horizontal ductable and cassette with many options and accessories to virtually fit in any environment.

Fig. 4: ELFOSpace terminal units are available in both 2-pipe and 4-pipe versions, either cased or uncased.

Fig. 5. Features and benefits also apply with alternative local units, such as radiant panels, induction terminals and chilled beams.

TECHNOLOGIES AND BENEFITS

The Clivet Enhanced Hydronic System is based on drivers such as: Reverse cycle heat pump to exploit renewable energy The electric Heat Pump technology is promoted and supported by the European Union with specific standards, such as the EU Directive 2009/28/CE of April 23rd 2009 that recognises ambient air as a renewable source. Compared to a combustion system, the electric Heat Pump technology allows: Energy saving and reduction of the CO2 emission by an average of 50% Use of electric energy, more and more produced through alternative and renewable

sources Operation reliability and reduced maintenance No fossil combustion and therefore absence of chimney, absence of periodical

controls on the emissions in the ambient and no local production of fine dust Cost reduction of first investment with the reversible models that use a single system

for both heating and cooling.

Fig. 6: Electric heat pump is the distintive technology: it gets rid of fossil fuels and direct emission in the environment while saving 50% on primary energy.

CONVENTIONAL COMBUSTION

HEAT PUMPS

Primaryenergy102

Fossilfuels

Thermalenergy102

Primaryenergy54,2

Hydroel.

Thermal

Renewable

Electricenergy25

Renewableenergy75

Free energyfromambient

100

100HEATPUMP

Avg eff. = 98%

SCOP = 4

47% saving on Primary energy50% saving on CO2 emissions

ConversionFactor = 2,17


Best Energy efficiency year-round High part-load efficiency results in great energy saving year-round, because by far it is the most frequent condition throughout the system’s life-cycle. Optimal performance applies in all functional modes, from cooling to heating. In this way, even the value of the built environment is increased.

Optimal capital cost The combination of Thermodynamic recovery and Modular Scroll technology applied on heat pumps results in sustainable efficiency. Air cooled SPINChiller units features top-level ESEER seasonal efficiency, even higher than VFD screw chillers (furthermore, those ones are non reversibile): this leads to reduced capital cost and minimal life cycle cost. In addition, the ZEPHIR Primary Air system allow great system simplifications, on pipeworks, central heating and cooling, ‘invest as-you-grow’ capability.

Simplified design The Clivet Enhanced Hydronic System is complete with all components that usually are provided separately. This reduces: design time: all accessories are matched to ensure the best overall efficiency installation cost: the accessories already mechanically connected, electrically wired

and individually tested, thus ready to be immediately operated overall dimensions: system components are integrated with the unit, thereby reducing

the technical area and increasing the floor space available for other uses. Furthermore, ZEPHIR is the stand-alone system for Primary Air: it produces heating and cooling capacity without any connection to central heating and cooling stations.

Great compactness ZEPHIR saves 50% in space, when compared to traditional Primary Air AHU’s solutions. Also the relevant technical rooms for pipeworks and controls are avoided. It also reduces the capacity of central heating and cooling central plant, thus the benefit on the overall design is even higher.

Fig. 7: The Heat pump technology allow one single system to operate in all seasons. Thus global design is much easier.

Fig. 8: Decentralisation with ZEPHIR is very effective in diluting capital cost over time.


To assess the effect of the Clivet Enhanced Hydronic System on both capital and overall cost, a mid-size office building with glazed facades has been analysed in year-round operation in the city of London, United Kingdom.

This performance has been compared to a traditional HVAC system, based on outdoor air AHU’s with rotary heat recovery (120 Pa pressure drop per air stream), air cooled liquid chillers with Screw compressors, gas condensing boilers.

To get a complete overview, the energy analysis has then been further done on the same building in different conditions:

Climate: Rome, Italy; Valencia, Spain; Krakow, Poland; Moscow, Russian Federation

Heat recovery technology: Passive cross-flow heat exchanger

Cooling technology: Inverter Screw, Centrifugal Magnetic bearing

Heating technology: Air-to-water heat pump

Building details and relevant design data (night set back values within brackets) are:

APPLICATION FOR MULTI-LEVEL OFFICE BUILDING

Cenni di cambiamento, social housing Milano, Italy

Woolmore Primary School London, United Kingdom.

Primary air

Attendance (0,12 persons/m2) nr. 792

Airflow (11 l/s per person) m3/h 31.360

Summer design, indoors

Temperature °C 25 (28)

Relative humidity % 55 (65)

Supply air primary temperature °C 20 (OFF)

Supply air primary relative humidity g/kg 9,5 (OFF)

Winter design, outdoors

Temperature °C 20 (18)

Relative humidity % 40 (40)

Supply air primary temperature °C 22 (OFF)

Supply air primary relative humidity g/kg not controlled

Internal loads (standard operation time)

Lighting W/m2 5

Electrical equipment (computers, printers, etc.). W/m2 5

Air conditioned space

Application - Offices

Net floor m2 6.600

Height m 3

Standard (business hours) operation time - 8am to 8pm Monday to Friday

Night set back operation time - 9pm to 7am

Monday to Friday Holidays 24h and Saturday

Each floor is 2,200 m2 wide, suitable for multi-tenant location.

During the unoccupied mode, night setback is an effective energy saving strategy.


Method for energy analyis

A dynamic simulation software, LEED® approved, is used to get space loads hourly.

All systems are then modeled through a ‘bin method’ year-round energy analyis: it considers load, capacity and power input performance depending on indoor and outdoor conditions. Integrating those power values by the occurrence (frequency) of the single temperature bin results in energy output.

The number of persons, compliant with most EU standards, and lighting are kept constant.

Moreover, the relative humidity per each outside temperature bin is the same in all locations.

To compare different energy sources, as electricity and gas, all output values have been converted to:

Primary Energy

CO2 emissions

Energy cost.

To allow proper comparison among different locations, the average EU conversion factors were used.

Primary energy

CO2

emissions Energy

cost

Electricity adsorbed 2,18

kWhp / kWhe 0,61

kgCO2 / kWhe 0,15

EUR / kWhe

Methane Gas 9,6

kWhp / Nm3 1,84

kgCO2 / Nm3 0,80

EUR / Nm3

kWhp kg EUR

kWhe

Nm3

To better describe the individual behaviour and compare all different functions, outputs have been grouped as:

Production of cooling and heating capacity using electricity: compressor chiller/heat pump, external fans, relevant pumps for chilled/hot water, collectively called Electric Generator (diagrams: deep blue colour)

Production of heating capacity using fuel (methan gas): gas boiler and relevant pumps for hot water circulation, collectively called Gas Generator (diagrams: red colour)

Primary Air stand-alone capacity production: ZEPHIR3 compressors, collectively called ZEPHIR3 Thermodynamic circuit (diagrams: light blue colour)

Primary Air circulation: supply fans, exhaust fans and enthalpy wheel drive motor, collectively called Handling fans (diagrams: green colour)

The analysis does not include fan coil motors, as they are invariant due to the same system design and operation in all scenarios.


Both the Clivet Enhanced Hydronic System and the traditional HVAC system provide Primary Air management and space air conditioning through local terminal units, fancoil type.

Individual sizing and configuration depend on ambient conditions and relevant building load profile.

CLIVET ENHANCED HYDRONIC SYSTEM

ZEPHIR systems provide local stand-alone Primary Air management and energy recovery: they are all located in technical rooms close to the space. They feature constant supply temperature control and include supply and return fan sections, double air filtration (G4 and electronic H10), summer dehumidification with reheating via hot gas recovery, constant airflow control. Electrical panel and automatic controls are in-built.

Central hot water or chilled water is supplied by SPINChiller air-to-water heat pump, to feed as many as 200 two-pipe fancoil units.

As the System is fully electric, no gas piping, relevant safety equipment and chimneys are needed.

SYSTEM DESIGN

ELFOSPACE

SPINCHILLER CHILLED / HOT WATER

ZEPHIR


TRADITIONAL HVAC SYSTEM

Primary air is provided by bespoke Air Handling Units (AHU) also located in technical rooms close to the space. Each AHU feature constant supply temperature control and include supply and return fan sections as well. Passive heat recovery is achieved through enthalpy wheel. Double air filtration is based on G4 and F7 bag filters. A ‘double function’ water coil provides either heating or cooling capacity. Summer dehumidification with reheating via hot water and constant airflow control are also included. As part of the on-site installation, units are completed with electrical panel and individual automatic controls. Global design includes suitable utility tunnels and corridors for all water pipework.

Central hot water is provided by gas fired condensing boilers, complete with gas piping and control, safety equipment, chimney on-site assembly.

Chilled water is supplied by air-cooled liquid chillers with screw compressors, shell and tube evaporators, aluminium finned condenser coils, axial fans.

Seasonal changeover, from chilled to hot water circulation and back, is provided by individual shut-off valves.

Both boilers and chillers result in larger capacity than Clivet Enhanced Hydronic System, as they must feed all Primary Air Handling Units and 200 two-pipe fancoils at a time.

TERMINAL UNITS

HOT WATER

PIPEWORK BOILER CHILLER

CHILLED WATER

AHU

CONTROLS


According to the bin-method strategy, the building load is described depending on outdoor conditions in the city of London, United Kingdom.

This a temperate climate: similar performances apply to Paris, Milan, Bilbao and Frankfurt.

Fig. 11: Individual building load and outdoor temperature occurency in London. Peak load occurs for a few hours per year. Most operation is requested at part load.

ENERGY ANALYSIS



Central Chilled Water

SPINchiller3 WSAN-XSC3 90.4 EXC Air-to-water heat pump

Cooling 244 kW (A35 W7) EER 2,78 ESEER 3,94 Heating 282 kW (A7 W45) COP 3,23 Q.ty 1

Air cooled liquid Chiller Screw compressor, stepless control

Cooling 370 kW (A35 W7) EER 3,1 ESEER 4,1 Q.ty 1

Central Hot Water

Gas condensing boiler Efficiency 102%

Heating 320 kW Q.ty 1

Local Primary Air

ZEPHIR3 SIZE 3 Exhaust air heat pump

Airflow 4000 m3/h (1100 l/s) Cooling 19,1 kW (A35 A25) Heating 20,7 kW (A7 A20) Recovery Thermodynamic Passive recovery pressure drop (per air stream) 0 Pa Q.ty 8

Air Handling Unit bespoke equipment

Airflow 4000 m3/h (1100 l/s) Cooling from chiller Heating from boiler Recovery Enthalpy wheel 70% Passive recovery pressure drop (per air stream) 120 Pa Q.ty 8

Both systems are selected on design conditions.

Their individual performance at different outdoor conditions leads to the overall energy requested to operate the systems.


Traditional HVAC system

Clivet Enhanced Hydronic System

Fig. 12: Further to the great energy saving to operate handling fans, the Clivet Enhanced Hydronic System benefits from the Heat Pump technology to considerably reduce also the primary energy to generate both cooling and heating capacity. This results in lower CO2 emissions as well.

LONDON: Primary Energy Consumption and CO2 Emissions

0

2000

4000

6000

8000

10000

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

-4 -2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28

Total CO2 emissions

Handling fans

ZEPHIR3 Thermodynamic Circuit

Gas generator

Electric Generator

Outdoor temperature [°C]

Primary Energy [kWh] CO2 emissions [kg]

0

2000

4000

6000

8000

10000

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

-4 -2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28

Total CO2 emissions


CO2 emissions [kg] Primary Energy [kWh]

Fig. 13: Compared to the traditional HVAC system (2), ZEPHIR (1) allows 51% saving on energy to operate fans.

Handling fans for Primary Air

Fig. 15: Compared to the traditional HVAC system (2), ZEPHIR3 (1) provides hot gas reheat for free and further increases the refrigeration circuit efficiency by 35%.

Reheat for Primary Air

0

3000

6000

9000

-4 -2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28

Primary Energy [kWh]


Fig. 14: Being totally stand-alone, ZEPHIR (1) requires no energy to circulate hot water and chilled water for Primary Air, as it would happen on the traditional HVAC system (2).

Water pumps for Primary Air

0

250

500

750

1000

1250

1500

-4 -2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28


2

0

100

200

300

400

500

600

-4 -2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28

1




2

1

2

1

Chiller

ZEPHIR3

(reheat off)

ZEPHIR3

(reheat on)

4,2

6,9

EER 25°C

9,3


Fig. 16: The Clivet Enhanced Hydronic System reduces at a time the carbon footprint of the building and the running cost to keep year-round the requested comfort conditions.

127.78863.198

179.508

111.947

279.110

212.578

0

100.000

200.000

300.000

400.000

500.000

600.000

TOTAL PRIMARY ENERGY [kWh]


8.7934.348

12.351

7.703

23.146

14.627

0

5.000

10.000

15.000

20.000

25.000

30.000

35.000

40.000

45.000

50.000

ENERGY COST [EUR]

LONDON: OVERALL CONSUMPTION

Gas Generator


Electric Generator

Handling fans

CLIVET Enhanced Hydronic System

586.406 -34%

387.723

35.75717.684

50.229

31.325

54.185

59.483

0

20.000

40.000

60.000

80.000

100.000

120.000

140.000

160.000

TOTAL CO2 EMISSIONS [kg]

140.171

108.492



44.290

26.678


CLIVETEnhanced Hydronic System

-23%

-40%


ROME

Fig. 17: Individual building load and outdoor temperature occurency in Rome.

EFFECT OF CLIMATE

This is a mediterranean climate: similar performances apply to Barcelona, Lisbon and Palermo.

Changing the location of the building results in new load profile. Therefore, both Systems have to be selected on different design conditions.

All remaining functions, technology and performance are unchanged.

Output figures confirm the benefits from the Clivet Enhanced Hydronic System.








Central Hot Water



Local Primary Air







Fig. 18: In mediterranean locations, most energy is requested in cooling operation. Also in this scenario, the Clivet Enhanced Hydronic System benefits from the superior thermodynamic efficiency of its components and the saving on handling fans for Primary Air.



ROME: Primary Energy Consumption and CO2 Emissions

Handling fans


Gas generator

Electric Generator

0

3.000

6.000

9.000

12.000

15.000

18.000

21.000

0

10000

20000

30000

40000

50000

60000

70000

80000

-4 -2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32

Total CO2 emissions



0

3.000

6.000

9.000

12.000

15.000

18.000

21.000

0

10000

20000

30000

40000

50000

60000

70000

80000

-4 -2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32

Total CO2 emissions




127.19463.030

429.918

92.770

171.413

285.133

0

100.000

200.000

300.000

400.000

500.000

600.000

700.000


Fig. 19: The Enhanced hydronic System, during the annual operating cycle, reduces the building running costs.

35.59117.637

120.298

25.958

33.220

79.785

0

20.000

40.000

60.000

80.000

100.000

120.000

140.000

160.000

180.000

200.000



8.7754.337

29.582

6.383

14.342

19.619

0

10.000

20.000

30.000

40.000

50.000

60.000

ENERGY COST [EUR]

ROME: OVERALL CONSUMPTION


728.525 -39%

440.933

189.109

123.380



52.699

30.339



-35%

-42%

Gas Generator


Electric Generator

Handling fans


VALENCIA

Fig. 20: Individual building load and outdoor temperature occurency in Valencia.

This is a hot climate: similar performances apply to Athens and Bangalore.









Central Hot Water



Local Primary Air






Fig. 21: The primary energy required and the CO2 total emissions of Enhanced hydronic System for the air conditioning of the building are much lower than the traditional solution with screw stepless compressor.



VALENCIA: Primary Energy Consumption and CO2 Emissions

Handling fans


Gas generator

Electric Generator

0

3.000

6.000

9.000

12.000

15.000

18.000

0

10000

20000

30000

40000

50000

60000

70000

-2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34

Total CO2 emissions



0

3.000

6.000

9.000

12.000

15.000

18.000

0

10000

20000

30000

40000

50000

60000

70000

-2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34

Total CO2 emissions




Fig. 22: The Enhanced hydronic System, during the annual operating cycle, reduces the building’s running costs.

Gas Generator


Electric Generator

Handling fans

VALENCIA: OVERALL CONSUMPTION


127.44563.198

622.938

83.048

139.512

437.390

0

100.000

200.000

300.000

400.000

500.000

600.000

700.000

800.000

900.000


ENERGY COST [EUR]


889.895 -34%

583.636

35.66117.684

174.308

23.238

27.034

122.389

0

50.000

100.000

150.000

200.000

250.000


237.003

163.311



8.7694.348

42.863

5.714

11.578

30.096

0

10.000

20.000

30.000

40.000

50.000

60.000

70.000

63.210

40.158



-31%

-36%


KRAKOW

Fig. 23: Individual building load and outdoor temperature occurency in Krakow.

This is a cold climate: similar performances apply to Munich, Wien, Warsaw, Stockholm.

In this location, the Clivet Enhanced Hydronic System is complete with:

Option “Hydronic recovery device for extended operating range” on ZEPHIR3 down to –20°C ambient

Gas condensing boilers to operate below –6°C ambient.

As far as the traditional HVAC system is concerned, larger coils on AHU results in additional 30 Pa internal pressure drop.

Fig. 24: The ‘Hydronic recovery device for extended operating range’ on ZEPHIR3 is suitable for application in cold climate and in hot humid climate. It is a compact device within the System, thus keeping unchanged the unit dimensions and consequently its compactness.











Central Hot Water



Local Primary Air






Fig. 25: The primary energy required and the CO2 total emissions of Enhanced hydronic System for the air conditioning of the building are much lower than the traditional solution with screw stepless compressor



KRAKOW: Primary Energy Consumption and CO2 Emissions

Handling fans


Gas generator

Electric Generator

0

1.000

2.000

3.000

4.000

5.000

6.000

7.000

8.000

9.000

10.000

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

-20 -17 -14 -11 -8 -5 -2 1 4 7 10 13 16 19 22 25 28 31

Total CO2 emissions



0

1.000

2.000

3.000

4.000

5.000

6.000

7.000

8.000

9.000

10.000

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

-20 -17 -14 -11 -8 -5 -2 1 4 7 10 13 16 19 22 25 28 31

Total CO2 emissions




Fig. 26: The Enhanced hydronic System, during the annual operating cycle, reduces the building’s running costs.

131.34572.666

201.161

159.826

412.114

272.496

24.446

0

100.000

200.000

300.000

400.000

500.000

600.000

700.000

800.000



9.0375.000

13.841

10.997

34.163

18.750

2.032

0

10.000

20.000

30.000

40.000

50.000

60.000

36.75220.333

56.288

44.722

80.082

76.249

4.715

0

20.000

40.000

60.000

80.000

100.000

120.000

140.000

160.000

180.000

200.000TOTAL CO2 EMISSIONS [kg]

ENERGY COST [EUR]

KRAKOW: OVERALL CONSUMPTION


744.620 -29%

529.434

173.122

146.019



57.041

36.779



-16%

-36%

Gas Generator


Electric Generator

Handling fans


MOSCOW

Fig. 27: Individual building load and outdoor temperature occurency in Moscow.

This is a very cold climate.

In this location, the Clivet Enhanced Hydronic System is complete with:

Option “Extrapower-H (with additional hot water exchanger, without electronic filters)” on ZEPHIR3 down to –40°C ambient

Gas condensing boilers to operate below –6°C ambient.

As far as the traditional HVAC system is concerned, larger coils on AHU results in additional 60 Pa internal pressure drop.

Fig. 28: The ‘EXTRAPOWER-H (with additional hot water exchanger, without electronic filters)’ option on ZEPHIR3 is suitable for indoor application in very cold climate. For most operating time, ZEPHIR3 is independent from central hot water.











Central Hot Water



Local Primary Air






The energy input to operate the EXTRAPOWER-H option is reported individually: it includes gas boiler consumption and pumping for hot water, collectively called EXTRAPOWER-H (diagrams: colour pink).

Fig. 29: The primary energy required and the CO2 total emissions of Enhanced hydronic System for the air conditioning of the building are much lower than the traditional solution with screw stepless compressor EXTRAPOWER-H uses only 15% of total primary energy of Enhanced Hydronic System. EXTRAPOWER-H produces only 11% of total CO2 dell'emissioni of Enhanced Hydronic System

EXTRAPOWER-H



Handling fans


Gas generator

Electric Generator


0

1.000

2.000

3.000

4.000

5.000

6.000

7.000

8.000

0

5000

10000

15000

20000

25000

30000

35000

40000

-25 -22 -19 -16 -13 -10 -7 -4 -1 2 5 8 11 14 17 20 23 26 29

Total CO2 emissions


0

1.000

2.000

3.000

4.000

5.000

6.000

7.000

8.000

0

5000

10000

15000

20000

25000

30000

35000

40000

-25 -22 -19 -16 -13 -10 -7 -4 -1 2 5 8 11 14 17 20 23 26 29

Total CO2 emissions



MOSCOW: Primary Energy Consumption and CO2 Emissions


Fig. 30: The Enhanced hydronic System, during the annual operating cycle, reduces the building’s running costs. EXTRAPOWER-H

Gas Generator


Electric Generator

Handling fans

MOSCOW: OVERALL CONSUMPTION


9.2944.532

14.478

11.962

46.514

17.450

8.935

10.362

0

10.000

20.000

30.000

40.000

50.000

60.000

70.000

37.79618.429

58.879

48.645

109.094

70.964

19.493

24.037

0

50.000

100.000

150.000

200.000

135.07465.861

210.419

173.846

561.192

253.610

107.225

124.640

0

100.000

200.000

300.000

400.000

500.000

600.000

700.000

800.000

900.000


ENERGY COST [EUR]


906.685 -20%

725.182


205.769

181.568



70.286

53.241



-12%

-24%


The case study in London can be now updated to check how much the recovery technology in the traditional HVAC system affects the year round energy performance. For this purpose, within the traditional HVAC system, the Air Handling Unit for Primary Air is now equipped with a standard sized cross-flow recovery, in lieu of the enthalpy wheel.


Fig. 33 When the traditional HVAC system features cross-flow recovery in lieu of enthalpy wheel recovery, the case study in London shows further benefit for the Clivet Enhanced Hydronic System. (W/ … = ‘Traditional HVAC system with’ …)

EFFECT OF HEAT RECOVERY TECHNOLOGY

Cross-flow 65% efficiency

Enthalpy wheel 70% efficiency

Thermodynamic recovery

Passive recovery pressure drop outdoor / exhaust [Pa]

200 / 200 120 / 120 0 / 0

Supply / Exhaust Fan power input [kW]

1,7 / 0,7 1,5 / 0,6 0,6 / 0,4


Gas Generator


Electric Generator

Handling fans

142.017 127.78863.198

179.547 179.508

111.947

307.945279.110

212.578

0

100.000

200.000

300.000

400.000

500.000

600.000

700.000


W/ Enthalpy wheel recovery

W/ Cross-flow recovery

-38%

387.723

586.406 629.509

Fig. 31 Most enthalpy wheels feature also latent exchange. The thick rotor matrix results in higher pressure drops and frequent cross contamination.

Fig. 32 Most cross flow heat exchangers feature only sensible recovery and further fan power input increase due to higher pressure drop on air streams.

The traditional HVAC system results in: Higher energy for cooling and heating production, due to lower recovery Higher energy for ventilation, due to higher pressure drop.

-34%



9.772 8.7934.348

12.354 12.351

7.703

25.53823.146

14.627

0

5.000

10.000

15.000

20.000

25.000

30.000

35.000

40.000

45.000

50.000

55.000

ENERGY COST [€]

Fig. 35: ZEPHIR3 allows further cost saving: 44% and 40% using respectively a cross-flow recovery in traditional solution in lieu of enthalpy wheel.

Fig. 34: ZEPHIR3 allows further reduction of CO2 emissions: 28% and 23% using respectively a cross-flow recovery in traditional solution in lieu of enthalpy wheel.

39.739 35.75717.684

50.240 50.229

31.325

59.77454.185

59.483

0

20.000

40.000

60.000

80.000

100.000

120.000

140.000

160.000

180.000




108.491

140.167 149.753 -28%

-44%

-23%

Gas Generator


Electric Generator

Handling fans




26.678

44.290 47.664

-40%


EFFECT OF COOLING TECHNOLOGY

Liquid chiller Screw

Stepless

Liquid chiller Multi Scroll

Liquid chiller Screw

Inverter

Liquid chiller Centrifugal Magnetic Bearing

EER (A35 W7) 3,1 3,1 2,9 3,3

ESEER 4,1 4,7 4,8 5,0

Chiller Capital cost reference -10% +15% +70%

Keeping the application in London as case study, it is now possible to check how much the cooling technology affects the overall performance. For this purpose, different air cooled chillers are used: they feature the most popular compressor combinations to date. To get a complete overview, the gap on their capital cost is reported as well, keeping the Screw stepless type as reference.

63.198127.788 127.788 127.788 127.788

111.947

160.539 179.508 168.902 155.919

212.578

279.091279.110 279.091 279.091

0

100.000

200.000

300.000

400.000

500.000

600.000

W/ Screw Stepless

W/ Screw Inverter

W/ Centrifugal Magnetic bearing

W/ Multi Scroll


387.723

567.418 586.406 575.781 562.798


Fig. 36: The Clivet Enhanced Hydronic System features 32% average saving on primary energy over traditional systems, regardless the cooling technology.


The Clivet Enhanced Hydronic System features the SPINChiller water-to-air reverse cycle heat pump to produce either cooling or heating capacity year round. Due to this double function, the cooling efficiency of other liquid chillers looks higher, but it results in a negligible benefit on the year round overall energy performance, as reported, despite their capital cost jumping even up to +70% over the reference Screw stepless type. Important! At the same nominal cooling capacity, the capital cost of SPINChiller heat pump and the reference Screw stepless type would be equivalent. As ZEPHIR is independent from the central cooling and heating stations, the Clivet Enhanced Hydronic System reduces by over 30% the SPINChiller size, thus its capital cost as well.


Fig. 38: The Clivet Enhanced Hydronic System features 39% average saving on energy cost over traditional systems, regardless the cooling technology.

17.68435.757 35.757 35.757 35.757

31.325

44.922 50.229 47.261 43.629

59.483

54.18054.185 54.180 54.180

0

20.000

40.000

60.000

80.000

100.000

120.000

140.000

160.000

W/ Screw Stepless

W/ Screw Inverter

4.3488.793 8.793 8.793 8.793

7.703

11.046 12.351 11.622 10.728

14.627

23.14423.146 23.144 23.144

0

5.000

10.000

15.000

20.000

25.000

30.000

35.000

40.000

45.000

50.000

W/ Multi Scroll


108.492

134.859 140.171 137.198 133.566

Fig. 37: The Clivet Enhanced Hydronic System features 20% average saving on CO2 emissions over traditional systems, regardless the cooling technology.



ENERGY COST [EUR]

Gas Generator


Electric Generator

Handling fans

26.678

42.983 44.290 43.559 42.665

W/ Screw Stepless

W/ Screw Inverter

W/ Multi Scroll




As a whole, the Clivet Enhanced Hydronic System is benefitial also in this scenario, with over 5% saving on primary energy, CO2 emissions and energy cost.

The capital cost for equipment and installation is also more effective, by over 20%.

Fig. 40: The Clivet Enhanced Hydronic System is effective on both energy performance and capital cost.

127.78863.198

111.947

281.479 212.578

0

50.000

100.000

150.000

200.000

250.000

300.000

350.000

400.000

450.000

500.000

Traditional HVAC system Screw Stepless multifunction heat pump


-5,3% 409.267 387.723

EFFECT OF HEATING TECHNOLOGY

Fig. 39: Although not needed in this Enhanced Hydronic System case study, the Clivet SPINChiller3 range includes the Multifunction version as well. Its Modular Scroll technology allows superior efficiency at part load operation, thus in the year-round cycle.

Electric Generator


Handling fans







Central Hot Water

Local Primary Air





Multifunction air sourced heat pump Screw compressor, stepless control


Let’s now move the traditional HVAC system in London from a gas boiler heating design to an all electric solution to produce cooling and heating capacity.

Due to opposite loads (space and primary air) at a time, a multifunction air sourced heat pump must be used in the traditional HVAC system, to provide chilled water and hot water at once.


Fig. 41: The energy input for primary air circulation in the Clivet Enhanced Hydronic System is far lower than in the traditional HVAC system

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

0

5000

10000

15000

20000

25000

30000

35000

-4 -2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28

Total CO2 emissions



LONDON: Primary Energy Consumption and CO2 Emissions

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

0

5000

10000

15000

20000

25000

30000

35000

-4 -2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28

Total CO2 emissions





Electric Generator


Handling fans


CONCLUSIONS

The Clivet Enhanced Hydronic System is based on the high efficiency reversibile heat pump technology. It always proves to be more beneficial than traditional solutions, regardless climatic profile, heat recovery technology, cooling or heating technologies.

The dynamic year-round analysis on a typical multi-level office building application results in:

Overall energy saving over 30% in most locations in year round operation

Minimal carbon footprint: double-digit CO2 reduction results in more opportunities for tax reduction and building certification, thus raising the building overall value

Up to 42% saving on energy cost: this is a further profit opportunity in the whole lifetime of the building

Furthermore, additional benefits from the Clivet Enhanced Hydronic System are:

Total Indoor Air Quality: advanced Primary Air technology with high efficiency filtration allow best hygienic performance and higher productivity

Higher Leasable Area: compact design and minimal pipework reduce technical rooms and allow the best architectural integration

Effective capital cost: in most applications the whole system results in saving also on the first investment. Its modular design further allows to spread out the investment over time

Earlier earnings: as the Clivet Enhanced Hydronic System is highly integrated, on-site work can be effectively reduced. Spaces can be rented or sold much before it would usually happen.

Those benefits apply in many other residential, commercial and industrial applications. They are also effective with different local systems.

Fig. 42: the Clivet Enhanced Hydronic System is also effective in Hotels, Restaurants, Congress centres, Industrial buildings and in many other applications.


APPENDIX Detail of analysis with reference to the city of London. Comparison between Clivet Enhanced Hydronic System and a traditional HVAC system with stepless screw chillers and gas boilers. Winter/Summer indoor air d.b. temperature [°C]=20/25 - Winter/Summer indoor r.h. [%]=40/55 - Winter/Summer Primary Air supply d.b. temperature [°C]=22/20 - Supply / Return Primary Air fan available static pressure [Pa]= 250/150

Application Offices, London, office hours from 8 am to 8 pm, Monday to Friday, based on an annual cycle Data summarising by 5°C temperature ranges, the mean value is shown. Frequency of occurrence in hours "bin method". Yield distribution and regulation = 0.8 * 0.9 = 0.72

APPLICATION FEATURES TOTAL Outdoor d.b. temp. / r.h. °C / % -5 / 87 0 / 88 5 / 87 10 / 83 15 / 76 20 / 66 25 / 53 30 / 43 No. hours (Mon-Fri / 8-20) - Day operation h 7 193 626 975 906 573 108 5 3.393 Total space thermal load kW -125,8 -90,2 -46,4 16,6 96,4 197,8 229,4 262,2 TRADITIONAL SYSTEM AIR HANDLING UNIT (n.8 x 4.000 m3/h) ENTHALPY WHEEL RECOVERY Temperatur/Humidity efficiency % 71,7/ 57,8 71,7/ 57,8 71,7/ 57,8 71,7/ 57,8 71,7/ 57,8 OFF 69,3/44,5 69,3/44,5 Pressure drop enthalpy wheel - outdoor/exhaust air side Pa 123 / 129 125 / 130 128 / 131 130 / 132 133 / 134 139 / 139 139 / 139 140 / 140 Enthalpy wheel motor power input kW 0,04 0,04 0,04 0,04 0,04 OFF 0,04 0,04 Enthalpy wheel total capacity output kW 29,9 23,8 16,5 8,8 0,9 OFF 0,6 1,7 Air outlet enthalpy wheel d.b. temp. / r.u. °C 13,2 / 46 14,3 / 46 15,8 / 48 17,2 / 50 18,6 / 52 20 / 60 25,0 / 54 25,9 / 50 TREATMENT COIL (HOT AND COLD) Total cooling/heating capacity kW 11,7 10,3 8,3 6,4 4,5 OFF 18,4 15,6 Off coil dry bulb temperature °C 22,0 22,0 22,0 22,0 22,0 OFF 14,5 16,9 Off coil air humidity ratio g/kg 4,4 4,7 5,3 6,1 6,9 OFF 9,5 9,5 REHEATING T COIL Total sensible capacity kW OFF OFF OFF OFF OFF OFF 7,3 4,1 Supply air dry bulb temperature °C OFF OFF OFF OFF OFF OFF 20 20 Supply air humidity ratio g/kg OFF OFF OFF OFF OFF OFF 9,5 9,5 SUPPLY/EXHAUST FANS Supply fan power input kW 1,5 / 0,6 1,5 / 0,6 1,5 / 0,6 1,5 / 0,6 1,5 / 0,6 1,5 / 0,6 1,5 / 0,6 1,5 / 0,6 CENTRAL CHILLED WATER OFF OFF OFF COOLING COOLING COOLING COOLING COOLING Compressor efficiency - OFF OFF OFF 5,4 5,0 4,6 4,2 4,0 Cooling capacity kW OFF OFF OFF 23,1 133,9 274,7 523,1 538,0 Total power input kW 0,0 0,0 0,0 5,1 31,5 69,2 147,1 158,8 CENTRAL HOT WATER HEAT HEAT HEAT HEAT HEAT OFF HEAT HEAT Heating capacity kW 311,1 244,2 159,4 72,5 51,4 OFF 83,1 46,8 Total power input kW 4,7 3,7 2,3 0,8 0,6 0,0 0,5 0,5 ELECTRICITY ADSORBED Electricity absorbed - enthalpy wheel motor kWh 2 62 200 312 290 0 35 2 Electricity absorbed - supply fan kWh 84 2.316 7.512 11.700 10.872 6.876 1.296 60 Electricity absorbed - exhaust fan kWh 34 926 3.005 4.680 4.349 2.750 518 24 Electricity absorbed - Central chilled water kWh 0 0 0 4.974 28.514 39.633 15.882 794 Electricity absorbed - Central hot water kWh 38 29 18 7 5 0 4 4 METHANE GAS Methane gas Nm3 225 4.859 10.288 7.291 4.799 0 925 24 TOTAL PRIMARY ENERGY Total primary energy (2,18 kWh/kWhe) kWh 344 7.267 23.403 47.247 95.984 107.386 38.663 1.927

594.964

Total primary energy gas (9,6 kWh/Nm3) kWh 2.156 46.644 98.769 69.991 46.068 0 8.883 232 TOTAL CO2 EMISSIONS Total CO2 emissions (0,61 kgCO2/kWh_electric) kg CO2 96 2.033 6.549 13.220 26.858 30.048 10.818 539

142.437

Total CO2 emissions (1,84 kgCO2/Nm3) kg CO2 413 8.940 18.931 13.415 8.830 0 1.703 44 COST Electricity (0,15 EUR/kWh_electric) EUR 24 500 1.610 3.251 6.604 7.389 2.660 133

€ 44.900

Methane gas (0,80 EUR/Nm3) EUR 180 3.887 8.231 5.833 3.839 0 740 19 ENHANCED HYDRONIC SYSTEM ZEPHIR3 SYSTEM (n.8 x 4.000 m3/h) Total capacity kW 37,5 31,2 23,6 16,3 9,3 OFF 19,4 16,7 Reheat capacity from hot gas recovery kW - - - - - OFF 6,8 4,2 Compressor power input kW 6,6 4,7 3,2 2,1 1,3 OFF 2,8 2,5 Off coil dry bulb temperature °C 22,0 22,0 22,0 22,0 22,0 20,0 14,5 16,9 Supply air dry bulb temperature °C 22,0 22,0 22,0 22,0 22,0 20,0 20,0 20,0 Supply air humidity ratio g/kg 2,3 3,3 4,7 6,4 8,1 9,6 9,5 9,5 SUPPLY/EXHAUST FANS Supply/Exhaust fan power input kW 0,6 / 0,4 0,6 / 0,4 0,6 / 0,4 0,6 / 0,4 0,6 / 0,4 0,6 / 0,4 0,6 / 0,4 0,6 / 0,4 CENTRAL CHILLED/HOT WATER HEAT HEAT HEAT COOLING COOLING COOLING COOLING COOLING Compressor efficiency - 3,2 3,2 3,1 4,4 5,1 5,2 4,7 4,4 Cooling/heating capacity kW 174,7 125,3 64,4 23,1 133,9 274,7 318,7 364,2 Total power input kW 61,0 43,7 23,4 6,1 30,9 62,4 79,0 96,0 ELECTRICITY ADSORBED Electricity absorbed - ZEPHIR3 thermodynamic circuit kWh 367 7.180 15.976 16.692 9.231 0 2.454 100 Electricity absorbed - ZEPHIR3 supply fans kWh 34 926 3.005 4.680 4.349 2.750 518 24 Electricity absorbed - ZEPHIR3 exhaust fans kWh 22 618 2.003 3.120 2.899 1.834 346 16 Electricity absorbed - Central chilled/hot water kWh 427 8.437 14.627 5.929 27.997 35.732 8.532 480 TOTALA PRIMARY ENERGY Total primary energy (2,18 kWh/kWhe) kWh 1.852,0 37.410 77.631 66.319 96.956 87.889 25.833 1.352 395.242 Saving 34% TOTAL CO2 EMISSIONS Total CO2 emissions (0,61 kgCO2/kWh_electric) kg CO2 518 10.468 21.722 18.557 27.130 24.593 7.229 378 110.595 Saving 23% COST Electricity (0,15 EUR/kWh_electric) EUR 127 2.574 5.342 4.563 6.671 6.047 1.778 93 € 27.111 Saving 40%


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