Field monitoring of a Nearly Zero Energy Building - HPC 2017 · 2017-06-02 · Carsten Wemhöner, 12th IEA HP Conference, Rotterdam, May 2017 Energy monitoring MINERGIE-A® index

12th IEA Heat Pump Conference 2017

Field monitoring of a

Nearly Zero Energy Building

Carsten Wemhöner

HSR University of Applied Sciences Rapperswil

Rotterdam, May 17, 2017

Carsten Wemhöner, 12th IEA HP Conference, Rotterdam, May 2017

Outline

Technical building concept

Energy flow building technologies

Energy monitoring

MINERGIE® Index

Heat pump

Free-cooling

Heat tape and legionella protection

PV/T-collector

Self-consumption

Conclusion

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Building envelope

First MINERGIE-A® certified building with mixed residential and office use

1206 m2ERA , divided into 367 m2 office and 839 m2 living space

Calculated specific heating demand of 33.8 kWh/(m2a)

Design value for the MINERGIE-A® index of -5.0 kWh/(m2a)

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Technical building concept

…

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128 m2, 23.7 kWp

PV/T: 7.1 m2,

1 kWp,el, 2.3 kWp,th

800 l 1000 l

11 boreholes à 79 m

33.8 kW (B0/W35)

HR 80%

500 l


Energy monitoring

MINERGIE-A® index calculation

Weighting factors MINERGIE-A®

1.0 for fossil fuels

2.0 for electricity

0.7 for biomass

0.6 for waste heat (incl. district heating by waste incineration)

0.0 for solar and geothermal energy

Measuring periods

First year of operation from May 2014 till April 2015

Second year of operation from May 2015 till April 2016

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𝑀𝑖𝑛𝑒𝑟𝑔𝑖𝑒 − 𝐴® − 𝑖𝑛𝑑𝑒𝑥 =2

1206 𝑚2(𝐸𝑉𝑒𝑛 + 𝐸𝐻𝑃 + 𝐸𝐻𝑅 + 𝐸𝑆𝑜𝑙 − 𝐸𝑃𝑉𝑇 − 𝐸𝑃𝑉)

EVen:

EHP:

EHR:

Energy consumption ventilation Energy consumption heat pump

Energy consumption heating element

ESol:

EPVT:

EPV:

Energy consumption circulation pump

Energy production PV/T-generator

Energy production PV-generator


Energy flow

…

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MINERGIE-A® index

Total consumption decreased from 1st to the 2nd year by 15%

Due to performed optimizations regarding additional heating systems

Heat pump largest share of the electrical consumption

Responsible for 45% in the 1st and for 58% in the 2nd year

PV-system with a specific yield of 1’030-1’040 kWh/kWp (24’500 kWh/a)

PV/T-collectors with 900 kWhel/a

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MINERGIE-A® index

Building fulfils the requirements of the MINERGIE-A® index

-8.6 kWh/(m²a) 1st year of operation

-15.0 kWh/(m²a) 2nd year of operation

November – February the limit value of 0 kWh/(m²a) is exceeded

Because of the higher energy use of the heat pump and the lower energy

production by the PV and PV/T-collectors

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Heat pump

Due to performed optimizations, the overall SPF increased from 4.24 to 4.48

SPF heating from 4.60 to 4.90

Optimizations

Longer running time for the heat pump with a wider temperature range

Heat pump operation time adapted to the consumer behaviour (DHW)

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Free-Cooling

Office space is cooled over a ground-coupled free-cooling

System performance factor for cooling operating reaches a value of 17

Regeneration of the boreholes leads to higher source temperatures for

DHW production in the summer time (till 16 °C)

Increase of the SPFDHW by 5%

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Heat tape and legionella protection

In the 1st year of operation responsible for 38% of the energy consumption

Through stepwise improvements reduction by 60% (-4’450 kWh)

1. Permanent operation of the heat tape (DHW pipe temperature of 55 °C)

2. Reduction of the DHW pipe temperature from 55 °C to 40 °C

3. Heat tape time has been restricted

4. Heat tape operation time adapted to the consumer behaviour

5. Operation time reduced to once a week (before twice a week)

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PV/T-collector

PV/T-collector

Production of 900 kWhel und 1‘300-1‘400 kWhth, yield of 280 kWh/m2collector

Collector performance factor for both years in the range of 0.27

The effect of higher electrical efficiency due to lower collector temperatures

could be approved

Overall seasonal performance factor SPFgen

Increase from 4.5 to 4.8

In the second year significantly less affected by the heat tape

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Temporal energy match (Self-consumption)

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source: Kalz, FhG-ISE

Demand cover factor

Supply cover factor


Self-consumption

The supply cover factor (SCF) is depending on the balancing period

SCF of 40% and DCF of 30%

For a balancing period of 5 min and without load management

In single-family houses typical SCF values are in the range of 15-25%

The office hours have a positive effect for the SCF and DCF

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Conclusion

Innovative technologies (PV/T, ground-coupled free-cooling)

could be well integrated in the building concept

Requirements of the MINERGIE-A® index fulfiled

Noticeable below the limit with -15 kWh/(m²a)

Optimization heat pump operation

Adaption of the standard default settings lead to an increase of the SPF by 0.25

Design values distinctly exceeded

Stepwise reduction of the energy consumption through improvements of the

additional heating systems and the heat pump (-4’500 kWh/a)

(~700 CHF/a cost reduction)

PV/T-collectors are not financially beneficial, yet

Payback time above 20 years

Energy monitoring useful for optimization of the system operation

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Carsten Wemhöner, IEA Heat Pump Conference, May 2017

Bundesamt für Energie BFE

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Acknowledgement

The support, advice and funding of the Swiss Federal

Office of Energy is highly acknowledged

The Projekt is a contribution to the

IEA HPT Annex 40 on

«heat pump concepts for nearly Zero energy buildings»

Information IEA HPT Annex 40: http://www.annex40.net

Bundesamt für Energie BFE

http://www.annex40.net/


Questions and discussion

Thanks for your attention

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Field monitoring of a Nearly Zero Energy Building - HPC 2017 · 2017-06-02 · Carsten Wemhöner, 12th IEA HP Conference, Rotterdam, May 2017 Energy monitoring MINERGIE-A® index

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