IEA HPT Exco Meeting – Oslo – 2022.05.10

GSHP Field Measurements•

KIWI Dalgård

•Moholt 50|50•

The SWECO building

Heat Pump Installations – Examples•

Water-source – ammonia and CO₂•

Ground-source – propane•

Air-source – propane

Dr.ing. Jørn Stene, COWI AS, jost@cowi.com
1
Illustrasjon – SiT

IEA HPT Exco Meeting – Oslo – 2022.05.10

KIWI Dalgård, Trondheim – Supermarked

Project Thesis
Marie Garen Aaberg (2018)
Photo – Øystein Thommesen AS

IEA HPT Exco Meeting – Oslo – 2022.05.10

KIWI Dalgård – Overview› The building – completed June 2017
› Passive house standard – 1250 m2› Energy efficient display cabinets & lighting system›

Solar panels (PV), 560 m2 + battery storage› CO2 refrigeration system› Standard DX system – 20 kW (-18 °C), 59 kW (+4 °C)› Heat recovery to ventilation air and heat to BTES

› Ground-source heat pump system› R410A heat pump units 2 x 38 kW at 4/50 °C› BTES – 8 boreholes, total 2110 m – 15 m distance› KIWI shop – space heating and snow melting3› External heat supply to 3 block of flats

Photo – Norgesgruppen

IEA HPT Exco Meeting – Oslo – 2022.05.10

Refrigeration/Heat Pump Plant – Thermal Energy FlowLT
LT(-18 C)MT(+4 C)HEATING DEMANDS
Heating coils

Ambient air
Surplus heat

BTES

Heating coils

Refrigeration plant

Radiators

Photo – Øystein Thommesen AS

Snow melting

BTES
4

Heat pump units

Blocks of flats

IEA HPT Exco Meeting – Oslo – 2022.05.10

Thermal Energy Supply – Principle System Sketch

Heating coils

From CO₂
gas coolerEl.
boilerSnowmeltingBlockof flats

Radiators

From CO₂
gas cooler

HEAT PUMPHeat system KIWI

BTES
Buffer tank5

System sketch – Marie Garen Aaberg

IEA HPT Exco Meeting – Oslo – 2022.05.10

Thermal Energy Supply – Principle Sketch
Heating system – 3 block of flats

CO₂ refrigeration plant
To heating coils

To BTESTo radiatorsEl.
boilerMT compressors

60 °C

50 °C

40 °C

45 °C

From
heat pump

Air-cooled
gas cooler

DHW

6

DHW
tank

LT

DHW
tank
System sketch – Marie Garen Aaberg

MT

Display cabinets

LT compressors

IEA HPT Exco Meeting – Oslo – 2022.05.10

Borehole Thermal Energy Storage (BTES)› The ground – from NGU* database› Greenstone and green slate› l  3.0 W/(mK), Rb calculated by EED› BTES› 8 boreholes each 264 m = 2,110 m

KIWI› Borehole distance 15 m

› Borehole heat exchanger› OD 40/2.4 – PN 10, SDR17, PE100› Smooth tube collector› Anti-freeze fluid› Hxi-35 (ethanol)
7*Geological Survey of Norway

IEA HPT Exco Meeting – Oslo – 2022.05.10

Measurements – Heat Recovery from Refrigeration Syst.
› CO₂ refrigeration system› Heat supply› To ventilation air – 90 000 kWh› Energy coverage factor – 92 % (as designed)

Heat supply (kWh)› Sub- and super-critical operation (50-95 bar)Refrigeration system

Heat pump

1

2

3

4

5

6

7

8

9

10

11

Month (2018)8

Measurements – Marie Garen Aaberg

IEA HPT Exco Meeting – Oslo – 2022.05.10

Measurements – Ground-Source System (BTES)› Acceptable temperature conditions

Temperatur (°C)

› Good annual thermal energy balance

Heat from refrigeration system+15 °C
SupplyReturnHeat extraction with heat pump
1

2

3

4

5

6

7

Month 2018

8

9

10

-1 °C

11
1

2

3

4

5

6

7

Month 20189

Measurements – Marie Garen Aaberg

8

9

10

11

IEA HPT Exco Meeting – Oslo – 2022.05.10

Measurements – Heat Supply from Heat Pump System› External heat supply to 3 block of flats – 160.000 kWh› Lower heat supply than originally designed (350.000 kWh/year)› Current BTES fully utilized (i.e. annual thermal energy balance)

Heat supply (kWh)Measurements – Marie Garen Aaberg

10

1

2

3

4

5

6

7

Month 2018

8

9

10

11

IEA HPT Exco Meeting – Oslo – 2022.05.10

Measurements – SCOP for the Heat Pump
› Average SCOP for both COP for both heat pump units – 2.9› Relatively high return temperature in heating system – 60/40 °C-system vs. 40/30 °C

COP (-)› Heat pump unit energy label B – should have been min. A+

11

1

2

3

4

5

6

55°C

Temperatur (-)

2.9

7

8

9

10

11

35°C

1

2

Month 2018

3

4

5

Return6

7

8Month 2018
Measurements – Marie Garen Aaberg

9

10

11

IEA HPT Exco Meeting – Oslo – 2022.05.10

KIWI Dalgård – Summary
Foto – Øystein Thommesen AS

Pros› Passive house standard – energy efficient technical installations› Thermal charging of BTES with surplus heat – good annual thermal energy balance› Heating of neighbouring buildings with ground-source heat pump›Cons
› Lower heat supply than originally designed – moderate SCOP
› Low quality heat pump – one compressor has been rebuilt from on/off to VSD› Poor performance of accumulator tank – tank has been rebuilt for better stratification› Further possible improvements:› More advanced/energy efficient CO2 refrigeration plant› Low-temperature heating system in the block of flats, e.g. 40/30 °C vs. 60/40 °C› Heat pump units with energy label A++ or A+++

12

› Heat pump units with natural working fluid (propane, R290)› Extension of the BTES for increased capacity

IEA HPT Exco Meeting – Oslo – 2022.05.10

Moholt 50|50, Trondheim – District Heating and Cooling
Varmesentral
Samlekummer
Energibrønner
Solfangere

Tower E
Kindergarten

Tower D

Tower C
Tower B

Library
Tower A

HK21

Norwegian Heat Pump Award 2017
Trondheim Energy Award 2017
Illustration – SiT/MDH Arkitekter

Project and Master Thesis
Anja Meisler (2019/20)

IEA HPT Exco Meeting – Oslo – 2022.05.10

Moholt 50|50 – Overview› Moholt 50|50 – extension of Moholt student town

Photo – Glamox› Builder – Studentsamskipnaden Trondheim (SiT)› Contractor thermal energy supply – AF Group› The buildings – passive house standard – 25,000 m2› 5 block of flats in massive wood – 632 apartm. (2017)› Commercial tenants 1st floor – laundry in one building› Library and kindergarten (2016/17)› Existing block of flats for students, HK21 (2019)› Heating and cooling› Ground-source heat pump – small-scale district heating/cooling› DHW heating, heating of ventilation air and snow melting› Thermal charging of BTES – 3 different sources
14› Space heating – el. baseboard heaters and el. floor heating

IEA HPT Exco Meeting – Oslo – 2022.05.10

Heating of ventilation air

DHW

0

Cooling of ventilation air
and charging of BTES

15

Illustration – Anja Meisler

Duration (hours)

Ambient temperature (°C)

Thermal power

Estimated Power Duration Curve – Heating and Cooling

IEA HPT Exco Meeting – Oslo – 2022.05.10

Heating Plant – Ground-Source Heat Pump and El. Boiler› Prefabricated heating plant› Heat pump, el. boiler, pumps, valves + house› R410A brine-to-water heat pump
› 3 identical heat pump units› 3 x 83 kW = 250 kW at 3/55 °C› 2 scroll compressors per unit
› On/off control› Energy label B› Constant supply temp. 50-52 °C (DHW heating)› Electro boiler (peak load, back-up)› 100 kW (power limited)16

Photo – UAB Enso Projects

IEA HPT Exco Meeting – Oslo – 2022.05.10

Moholt 50|50 – Principle Energy Flow Diagram
COOLING DEMAND
Cooling of ventilation air
Heat recovery from ventilation air

SnowmeltingHeat recovery
from grey water

Heating ofventilation air

Heatingof DHW

Solar
collectors
HEATING DEMAND

Heat pump units x 3

17

BTES
23 boreholes in bedrock

Photo – Fredrik Myhre
Illustration – Anja Meisler

IEA HPT Exco Meeting – Oslo – 2022.05.10

Thermal Energy System – Principle Design
Heat from solar
collectors

Heat fromgrey water

El. boiler
Heat fromvent. air
50 °C

Heat pumpunits x 3

BTES
18

System sketch – Anja Meisler

Heating demands• DHW• Ventilation air• Snow melting

IEA HPT Exco Meeting – Oslo – 2022.05.10

Sub-station – DHW Heating and Heating of Ventilation Air
DHWC
APURGO antiLegionella system

DHW

Heating ofventilation air

48 °C
DHW storage tanks
50 °C
From heating plant

19

Sketch – Anja Meisler

Energy meter

City water

Temperature sensor
Pressure sensor
Flow meter
Motor valve

(2) Heat fromventilation air

IEA HPT Exco Meeting – Oslo – 2022.05.10

BTES and Pipeline System› The ground – from NGU* database› l  3 W/(mK), Rb  0.11 (mK)/W(1) Grey water
heat exchanger› BTES› 23 x 250 m = 5,750 m› Borehole distance 5 to 15 m
› OD40/2.4, PN10/SDR17/PE100› Smooth tube collector› Anti-freeze fluid – Hxi-24 (ethanol)› Thermal charging (1) + (2) + (3)› Pipeline systems
20(3) Solar collectors› No Thermal Response Testing!
Heating plant

Connection wells
Boreholes› Heat distribution (50 °C)

Heat distribution pipes› Heat extraction and cooling (0-15 °C)

Heat extraction / cooling pipes
Sketch – Anja Meisler

IEA HPT Exco Meeting – Oslo – 2022.05.10

DHW – Calculated Energy Demand vs. Measurements› DHW demand based on measurements from other student towns› Teknobyen (SiT)› Measured 900-1100 kWh person/a› 0-10 % deviation from design value› DHW heating systems should
preferably be designed according
to field measurements!

Energy (MWh)› Lerkendal studentby (SiT)

Domestic hot water (DHW) demand
Design› Project «Varmtvann2030»› Other extensive, high-quality
field measurements
21

Measured
Measurements – Anja Meisler

2017

2018

Design value

2019

IEA HPT Exco Meeting – Oslo – 2022.05.10

Heat Recovery from Grey Water – Heat to BTES
› Drain pipe ID 100 mm› Grey water temperature approx. 30 °C› Grey water pipe with counterflow heat exchanger› Indirect system design with circulating anti-freeze fluid› Transfer of heat to BTES via “cooling pipelines” (PE100)› Heat transfer tube ID 185 mm, 5 x 5 m = 25 m
› Heat exchanger surface in stainless steel› Copper rings to prevent biofilm
Anti-freeze fluid› Specific heat supply 2-6 kW/m2› Costs excl. trench 150.000 €

22

Grey
water

Sketch – Anja Meisler

IEA HPT Exco Meeting – Oslo – 2022.05.10

Ventilation Air – Heating, Cooling and Heat to BTES
› Heating demand› Heat recovery unit (hmax = 84 %)› Reheating with combi-coil (20 ° C)

› tambient > 12 °C (7 °C)› Max. heating of supply air withheat recovery unit (t > 18 °C)› Cooling of supply air to setpointtemperature with combi-coilHeat recovery

DamperFilterDamperExhaustExhaustrpm

SupplyInlet
DamperFilterRotating
heat
exchanger

Combi-coil› Heat to BTES

› Cooling demand› Cooling of supply air to setpointtemperature with combi-coil23› Heat to BTES

Sketch – Anja Meisler•

Heating of ventilation air••

Cooling of ventilation air
Heat recovery to BTESIEA HPT Exco Meeting – Oslo – 2022.05.10

Solar Collectors – Heat to BTES
› Solar collectors at the kindergarten roof
› Flat (“standard”) solar collectors› 29 x 2.51 m2 = 73 m2› Setpoint for heat exchange 20 °C› Costs excl. installation 100.000 €› Prefabricated solar station› Plate heat exchanger x 2› Primary pump
› Secondary pump

› Valves

24

IEA HPT Exco Meeting – Oslo – 2022.05.10

Measurements – Thermal Charging of BTES› 1) Grey water› Moderate temperature

Grey water
Solar collectors
Ventilation air› Heat supply the entire year
› 175 MWh in 2019 – 50 %› Low temperature› Heat supply April to Sept.
› 130 MWh in 2019 – 38 %› Solar collectors

Energy (MWh)› 2) Ventilation air

350 MWh› High temperature› Heat supply Feb. to Oct.

› 40 MWh in 2019 – 12 %25
Measurements – Anja Meisler

MonthIEA HPT Exco Meeting – Oslo – 2022.05.10

Heat from Ventilation to BTES – tambient > 12 °C or 7 °C

Temperature (°C)

23 °C2500 hours – 130 MWh

12 °C
7 °C

4550 hours - 230 MWh

Ambient temp. duration curve
Temperature limit for heat recovery
Design temperature limit (12 C)
Set-point temperature supply air
Average exhaust air temperature

26
Illustration – Anja Meisler

Duration (hours)

IEA HPT Exco Meeting – Oslo – 2022.05.10

Measurements – Temperature Development in BTES

Temperature (°C)

Average temperature from BTES
Average temperature to BTES
Average temperature thermal charging

14 °C
10 °C

Good annual thermal energy balance
2 °C
2016

27

2017

Measurements – Anja Meisler

2018

0 °C

Month

2019

2020

IEA HPT Exco Meeting – Oslo – 2022.05.10

Measurements – Monthly Heat Supply from Heating Plant

Energy (MWh)Heat pump
Electro boiler

28

Measurements – Anja Meisler

1070 MWh

Month

IEA HPT Exco Meeting – Oslo – 2022.05.10

Measurements – Temperatures for Heat Pump Unit no. 1

Energy (MWh)Dt 43-52 °C

29Compressor
failure 

Temperature lift
Condenser – outlet
Evaporator – outlet
Evaporator – inlet

Measurements – Anja Meisler

MonthIEA HPT Exco Meeting – Oslo – 2022.05.10

Measurements – SCOPheat and SCOPtot for the Heat Pump
› Measuring period› November 2018 – October 2019

› Measured SCOP (method ref. SEPEMO)› SCOP1heat

3.2

Heat supply, excl. pumps› SCOP2heat

2.8

Heat supply, incl. pumps› SCOP1tot

3.8

Heat supply + free cooling, excl. pumps› SCOP2tot

3.4

Heat supply + free cooling, incl. pumps› Measured SCOP – 40-45 % Carnot efficiency› Moderate SCOP due to low-quality heat pump

30

SCOP1heat 3.2

67 %IEA HPT Exco Meeting – Oslo – 2022.05.10

Moholt 50|50 – Summary›Pros› Zero emission neighbourhood with small-scale district heating/cooling system› DHW design value from field measurements – very low deviation› Excellent concept for heating plant and distributions systems› 48 °C only for DHW heating – enabled by the Apurgo anti-Legionella system› Thermal charging of BTES from 3 sources – good annual thermal energy balance› Prefabricated heating plant – cost-efficient, fancy concept›Cons› Low-quality heat pump - all 6 compressors have been replaced› On/off compressor control – should have used VSD (higher SCOP and lower wear/tear)› R410A (HFC) – should have used units with a natural working fluid, R290 or R717
31

› Operational problems with the DHW storage system in the sub-stations› The solar collectors are expensive and supplies minimum heat

IEA HPT Exco Meeting – Oslo – 2022.05.10

The SWECO Building, Bergen – Office Building

Master Thesis
Marie Garen Aaberg (2019)
Photo – Og arkitekter AS

IEA HPT Exco Meeting – Oslo – 2022.05.10

The SWECO Building – Overview› The building – offices/shops›

Shops 1st floor, offices 2nd to 4th floor, total area 18,000 m²›

Passive house standard, Energy label A, Breeam-Nor Excellent›

Solar panels (PV) on roof-top and façade

Illustration – SWECO Norge AS› The thermal energy system›

Heating and cooling demands› 110 kW – heating and DHW heating› 195 kW – space cooling and process cooling – adiabatic precooling›

Heat recovery from grocery store›

Base load – ground-source heat pump
› 1 heat pump unit – ammonia (R717) as working fluid

33› BTES – vertical boreholes around the building›

Peak load/back-up – district heating

Illustration – SWECO Norge AS

IEA HPT Exco Meeting – Oslo – 2022.05.10

Measured Power Duration Curves – Heating and CoolingAmbient temperature (°C)

Power demand (kW)110
kWTot. heating demand
DHW
Tot. cooling demand
Process coolingAmbient temp.

195
kW

Chart – Marie Garen Aaberg

34

Duration (hours)

IEA HPT Exco Meeting – Oslo – 2022.05.10

Borehole Thermal Energy Storage (BTES)› The ground – from NGU database› Greenstone and green slate› l  3.5 W/(mK), Rb calculated by EED› BTES› 15 boreholes each 220 m = 3,300 m› Borehole distance 15 m

› Borehole heat exchanger

Machineryroom› OD 40/2.4 – PN 10, SDR17, PE100› Smooth tube collector› Anti-freeze fluid

Building› Water (min. temp. 3 °C) – less robust operation range› No exchangers required vs. heating and cooling systems
35

Sketch – Marie Garen Aaberg

15 m

IEA HPT Exco Meeting – Oslo – 2022.05.10

High-Efficiency Heat Pump Unit – Ammonia as Refrigerant
Photo – Marie Garen Aaberg›

Tailor-made, high-efficiency heat pump unit›

190 kW cooling capacity at 10/38 °C›

Ammonia (NH₃, R717) as refrigerant – 20 kg›

6-cylinder open piston compressor with VSD,
15-56 Hz (28-100 %) and cylinder unloading

Photo – Marie Garen Aaberg

16 bar safety valves
23 bar safety valves

Liquidseparator

Compressor›

Heat pump unit in gas-tight, ventilated
cabinet with leak detector and alarmsystem (cf. NS-EN 378)›

Double low/high-pressure safety valves
with exhaust at roof-top

Condenser
Motor

36

Evaporator
Sketch – Marie Garen Aaberg

Float valve

IEA HPT Exco Meeting – Oslo – 2022.05.10

Principle System Sketch of the Thermal Energy System
System sketch – Marie Garen Aaberg

Cooling –computers

Cooling –ventilation air

Space heating

10-12/17 °C

Districtheating50-60/30 °C

Water
BTES

Heat pump andchiller unit
Water

›
37

Preheating DHW

RT – temperature

P – pump

RD – pressure diff.

MV – 2-way valve

OE – energy meter

MV – 3-way valve
Closing valve

Water as secondary fluid – no heat exchangers between BTES and cooling/heating system

IEA HPT Exco Meeting – Oslo – 2022.05.10

Thermal Energy System – HEATING Mode
System sketch – Marie Garen Aaberg

Heating –ventilation air Space heating

Cooling –computers
15 °C

Districtheating

BTES

Heat pump unit
RT – temperature
RD – pressure diff.

Preheating DHW

38

Ambient temp. comp.

›Heating demand – space heating, heating of ventilation air and pre-/reheating of DHW›

Cooling demand – covered by cold water from BTES/evaporator (100 % “free cooling”)

IEA HPT Exco Meeting – Oslo – 2022.05.10

Thermal Energy System – COOLING Mode
System sketch – Marie Garen Aaberg

Cooling –computers

Cooling –ventilation air›

Preheating of DHW +reheating with electricheater, no other heating
demands›

Heat pump operated asliquid chiller

RT – temperature

15 °C

10 °C

RD – pressure difference
Ambient temp. comp.

35 °C

30 °C

BTES

Liquid chiller unit

Preheating DHW

39›

Covers the entire coolingdemand in the building›

Excess condenser heatrejected to BTES›

Heat pump has never been
in “liquid chiller mode”

IEA HPT Exco Meeting – Oslo – 2022.05.10

Measurements – Temperature in BTES vs. Qevaporator
Measurements – Marie Garen Aaberg

5 °C

April

May

Good annual thermal energy balance

June

BTES return temperature

40

Evaporator capacity (kW)Temperature (C)

14 °C

July

AugustSeptember

BTES supply temperature

OctoberNovember

Evaporator capacity

IEA HPT Exco Meeting – Oslo – 2022.05.10

Measurements – SCOP for the Heat Pump
SCOP1heat

SCOP2heat

SCOP1tot

SCOP2tot

3.6

SCOP

3.4
2.7
2.5

Measurements – Marie Garen Aaberg
Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

TOTAL

› Moderate SCOP due to low part load operation – oversized heat pump vs. BTES capacity
41

IEA HPT Exco Meeting – Oslo – 2022.05.10

Measurements – SCOP for the Heat Pump
Evap. inlet

Evap. outlet

Cond. outlet

Temperature lift

SCOP

Measurements – Marie Garen Aaberg

50

40

Heat pump load (%)

Temperature (°C)

30

SCOP

20
10
0

› Moderate SCOP due to low part load operation› 10 to 45 % of max. capacity› Compressor capacity control
Jan

Feb

Mar

Apr

May

Measurements – Marie Garen Aaberg

42

Jun

Jul

Aug

Sep

Oct

Nov

TOTAL

› VSD (28-100 %)› Cylinder unloading (10 to 28 %)IEA HPT Exco Meeting – Oslo – 2022.05.10

Measurements – SCOPheat and SCOPtot for the Heat Pump
› Measuring period› 2018› Measured SCOP (method ref. SEPEMO)› SCOP1heat

3.4

Heat supply, excl. pumps› SCOP2heat

2.5

Heat supply, incl. pumps› SCOP1tot

3.6

Heat supply + free cooling, excl. pumps› SCOP2tot

2.7

Heat supply + free cooling, incl. pumps› Measured SCOP 45-50 % Carnot efficiency› Moderate SCOP due to low part load operation (oversized heat pump)

43

SCOP1heat 3.4

70 %IEA HPT Exco Meeting – Oslo – 2022.05.10

The SWECO Building – Summary›Pros› Passive house bldg., Breeam Excellent – energy efficient technical inst. incl. heat recovery› High-quality, high-efficiency heat pump unit with ammonia as refrigerant› Water as secondary fluid in the BTES – innovative design and operation› The BTES covers the entire cooling demand of the building›Cons› Oversized heat pump unit – moderate SCOP due to low part load operation› BTES covers the entire cooling demand (100 % free cooling)› BTES not optimized with e.g. EED vs. actual heating and cooling demands› Thermal response testing not carried out› Improvement for heat pump – lower design capacity (100 kW) or application of two compressors› Design of DHW heating concept not optimal – only 20 % energy coverage
44Ground-Source
Heat Pumps
How to Achieve HighQuality Installations?

45

IEA HPT Exco Meeting – Oslo – 2022.05.10

Heating and Cooling Demands› Data crucial for correct design/operation of GSHP plant incl. BTES
› Space heating/cooling – calculate with high accuracy› Apply adequate software and sufficiently detailed input› Experience – calculations vs. field measurements› Annual energy demands (kWh/year) always larger than calculated› Peak power demands (kW) normally lower than calculated› DHW and process cooling demands› DHW – use data from field measurements if available› Process cooling – use equipment data + field measurements› Apply duration curves for heating/cooling during design› Provides a total overview of the thermal demands
46

IEA HPT Exco Meeting – Oslo – 2022.05.10

BTES – Borehole Thermal Energy Storage› Overall BTES design – energy and temperature balance› Detailed calculation with e.g. EED or IDA ICE› Thermal Response Testing (TRT) as design basis for larger systems› Design of BTES components› Use high-performance borehole heat exchanger (collector)› Design pipelines and heat exchangers with low Dp› Use high-efficiency pumps (IE3, MEI>0.4), optimized pump control› Design for correct flow rate in borehole heat exchangers – approx. 0.5 litres/s› Apply environmentally friendly anti-freeze fluid with good thermophysical properties› Install adequate deaerator and fine filter in borehole circuit› Consider thermal charging of BTES
47

› Sources – ventilation/ambient air, grey water, condenser heat etc.

IEA HPT Exco Meeting – Oslo – 2022.05.10

GSHP Plant› High-efficiency and high-quality heat pump units› ErP energy label min. A++, Eurovent energy label min. A› No temperature limitation vs. heating system› Preferably 2 heat pump units› Increased flexibility – better part load properties› Compressor capacity control› Scroll compressors – variable speed drive (VSD)› Piston compressors – VSD + possibly cylinder unloading› Screw compressors – VSD + slide valve control + vi control› 100 % environmentally friendly long-term refrigerants› Natural fluids – ammonia, propane or CO₂ – high SCOP
48

IEA HPT Exco Meeting – Oslo – 2022.05.10

GSHP and Secondary Systems› GSHP plants should normally be designed for possible chiller operation› Free cooling only – moderate cooling capacity and minimum flexibility› Extra heat rejection circuit with heat exchanger, pump, 3-vay valve and closing valves› Optimized design for heating, DHW and cooling systems› DHW heat pump design – adapted to annual DHW heating demand and temp. level› Preheating, preheating + reheating (desuperheater) or separate DHW heat pump

› Low-temperature heating system (dim. temp. ≤ 50-60 °C)› Capacity control according to outdoor compensation curve› High-temperature cooling system (dim. temp. ≥ 12 °C)› Other important issues› Hydraulic separation of heat pump and heating system
49› Serial connection of heat pump and peak load – correct control

IEA HPT Exco Meeting – Oslo – 2022.05.10

Instrumentation – Commissioning – Trial Period› Instrumentation – heat pump system incl. BTES
› Accurate temperature sensors + thermal/electric energy meters› Quality insurance of sensors and measuring system› Commissioning› Functional testing, system adjustment etc.
› Site Acceptance Test (SAT) – heating/cooling capacities and COP› Trial operation period› Preferably 12 month period for GSHP systems› Lifelong operation› Operating status – optimized operation and fault detection› Historical data presentation – COP, SCOP, SEI*, BTES temp. etc.
50

*SEI = System Efficiency Index  hC

IEA HPT Exco Meeting – Oslo – 2022.05.10

NTNU Field Measurements Have Contributed to› NTNU-SINTEF FME «Zero Emission Buildings» and«Zero Emission Neighbourhoods in Smart Cities»,
FME ZEB/ZEN (2010-16 – 2017-24)› http://www.zeb.nohttps://fmezen.no› IEA Heat Pumping Technologies Annex 40/49– «Heat Pumps in nZEB» (2012-15, 2016-20) og
Annex 52 «Long term Performance Measurementsof Ground-Source Heat Pump Systems» (2018-21)› https://www.annex49.net› https://heatpumpingtechnologies.org/annex52/
Norwegian activity financed by Enova and FME ZEB/ZEN
51

IEA HPT Exco Meeting – Oslo – 2022.05.10

SNR, Molde/Kristiansund – Hospital

52

IEA HPT Exco Meeting – Oslo – 2022.05.10

Heating/Cooling of a Hospital – Thermal Energy Systems› Buildings – 44,000 m2› Space and ventilation air heating

60/35 °C

› Process and space cooling

12/16 °C

› Heat pump and cooling system› 2 x brine-to-water units – ammonia (R717)› Hot water (DHW) heating system› 2 x brine-to-water units – CO₂ (R744)› Emergency cooling system› 2 x water-to-water units – propane (R290)› Refrigeration systems
53› CO2 (R744) – centralized plant and single-room inst.

› Propane (R290) – single-room installations only

IEA HPT Exco Meeting – Oslo – 2022.05.10

SNR – System Sketch of the Heat Pump System

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IEA HPT Exco Meeting – Oslo – 2022.05.10

SNR – Seawater System› Seawater – heat source/sink for:› Ammonia and CO₂ heat pump units› Free cooling (direct/renewable cooling)› Indirect system design› Pump well
› Suction/return pipelines› Twin pumps› Plate heat exchangers – titanium plates› Inlet at -50 m› Secondary brine circuit (EG)› Seawater temperatures› Min.
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5 °C› Max. 10 °C

IEA HPT Exco Meeting – Oslo – 2022.05.10

Heating/Cooling – NH₃ Heat Pump/Liquid Chillers Units
›

›

›

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Capacities›

Heating – 2 x 460 kW (3/52 °C)›

Cooling – 2 x 560 kW (10/40 °C)

Components›

Piston or screw compressors – VSD control›

Plate-and-shell heat exchangers

Ammonia (NH3, R717) as refrigerant›Superior thermophysical properties›

B2L – higher toxicity, lower flammability›

Low charge, leakage-proof units›

Separate machinery room›

Leak detectors – alarm system›

Water scrubber for R717 gas cleaning

IEA HPT Exco Meeting – Oslo – 2022.05.10

DHW Heating – CO₂ Heat Pump Units› Heating capacity
57› 2 x 45 kW at 3 °C and 12/77 °C› DHW system incl. DHW tanks› Optimized for CO₂ heat pumps

IEA HPT Exco Meeting – Oslo – 2022.05.10

Frøya Helsetun, Frøya – Nursery/Care Home58

IEA HPT Exco Meeting – Oslo – 2022.05.10

Heating/Cooling of a Nursery/Care Home – GSHP
› Buildings – 7,960 m2› Space and ventilation air heating

45/35 °C

› Process and space cooling

12/18 °C

› Heating and cooling plant› Brine-to-water heat pump units› Heating capacity: 2 x 145 kW (0/45 °C)› Cooling capacity: 2 x 160 kW (12/35 °C)› Borehole system in bedrock (BTES)

Frøya› 30 vertical energy wells each 300 m› 15 m average borehole distance› Peak load system› Electro boiler – 310 kW
59› Electric heaters in DHW tanks

Trondheim

IEA HPT Exco Meeting – Oslo – 2022.05.10

System Sketch of the Ground-Source Heat Pump System

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IEA HPT Exco Meeting – Oslo – 2022.05.10

GSHP with propane (R290) as Refrigerant› Brine-to-water heat pump units› 2 x 145 kW heating power (0/45 °C)› Semi-hermetic piston compressor› Variable speed drive (VSD) – 25-70 Hz› Max. 60 °C outlet water temperature (0/60 °C)› Propane (R290) as working fluid› 100 % environmentally friendly – excellent properties› Lower toxicity – higher flammability (A3)

› Safety measures according to EN378:2016› ATEX and CE certified units› Ventilated cabinet with leak detector – alarm system› Ex proof exhaust fan
61› Exhaust duct and blow-off line from safety valves to Ex sone on roof-top› Risk assessment mandatory

R290

IEA HPT Exco Meeting – Oslo – 2022.05.10

GSHP with propane (R290) as Refrigerant
Blow-off line from safety valves

Sealed box for power supply,
contactors, fuses, controllers etc.

Exhaust duct, ventilation

ATEX certified
and CE marked
heat pump unit
VSD piston
compressor

62

Leak detector connected
to alarm system

Gas tight, ventilated cabinet (min. -20 Pa)

IEA HPT Exco Meeting – Oslo – 2022.05.10

BTES – 30 Boreholes Each 300 m Deep

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IEA HPT Exco Meeting – Oslo – 2022.05.10

BTES – Simulations and Temperature Development

Very good thermal energy balance in BTES

› Thermal response testing (TRT) of the ground› Heat pump, heating – 290 kW› Heating 300,000 kWh/year – DHW 60,000 kWh/year› SCOP, heating – 4.5
64› Heat pump, cooling – 310 kW› Cooling – 210,000 kWh/year

IEA HPT Exco Meeting – Oslo – 2022.05.10

Tillertorget, Trondheim – Shopping Mall

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IEA HPT Exco Meeting – Oslo – 2022.05.10

Heating/Cooling of a Shopping Mall – Retrofitting› Tillertorget – retrofitting›

Shopping mall from 2005 – 30,000 m2›

Certified acc. to BREEAM-Nor «In Use»›

A) Air-to-brine liquid chiller plant›B) Air-to-brine heat pump/liquid chiller plant› A) Liquid chiller›

Cooling of ventilation air – 1 unit›

294 kW cooling capacity at 7/12 °C and 25 °C› B) Reversible heat pump / liquid chiller

66›

Cooling or heating of ventilation air – 2 units›

2 x 73 kW heating capacity at -15/35 °C

IEA HPT Exco Meeting – Oslo – 2022.05.10

Specifications for the Air-Source Heat Pump Units› Evaporator›

2.5 mm lamella distance (<1 mm*) – demand control defrosting system›

Extra surface coating of lamellas (epoxy – corrosion resistant)› Compressor›

Piston compressor – excellent at large variations in p›

Variable speed drive (VSD) or cylinder unloading› Propane (R290) as working fluid›

Low pressure ratio (p) and low discharge gas temp.

› Heat pump unit properties

67›

Stop temperature -20 °C (-12 °C*)›

62 °C outlet water temperature at -10 °C (40 °C*)›

Low noise level (“low noise” or “ultra low noise”)* Conventional air-to-water liquid chiller

IEA HPT Exco Meeting – Oslo – 2022.05.10

Air-Source Heat Pump/Chiller System – Heating or Cooling

68

IEA HPT Exco Meeting – Oslo – 2022.05.10

Outlet water temp. (°C)

Outlet water temp. (°C)

Roof-Mounted Units – Approx. 6 kg Propane per Circuit

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COOLING

Ambient air temperature (°C)

62 °C

47 °C

HEATING-20 °C

Ambient air temperature (°C)

Heat pump &Liquidliquid chiller units
chiller unit

Thank you for your attention!
Jørn Stene
COWI AS

JOST@cowi.com

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