UNEP - ECA network and thematic meetings in Ohrid – RAC meeting Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia MONITORING THE PERFORMANCE IN REAL-LIFE OF GROUND WATER SOURCE HEAT PUMP SYSTEM IN SERBIA Dipl.-Ing. Slobodan Pejković 1

GROUND WATER SOURCE HEAT PUMP  Energy most efficient units for heating and cooling application,  Use ground water as a heat source in the heating mode,  Use ground water as a heat sink in the cooling mode,  Ground water temperature is in the range of 13 to 16ºC throughout the year. This paper presents the power consumption required for the operation of the heating and cooling (HVAC) system in a period of one year for the residential part of the commercial and residential building in Belgrade. (Zemun) located immediately at the river Danube. The measurements showed that the average annual consumption of electricity for heating and cooling is 69 kWh/m 2. Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 2

SHALLOW GROUND WATERS  Shallow ground waters – depths of up to 50 m  Total ground water resource in Serbia – approximately l/s  Current exploitation accounts for about 20%.  The well at the site has the mass flow of 5 l/s,  Maximum requirement of the site amounts to 2.8 l/s. Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 3

Gross area of the residential part is approx. 250 m 2; Net area of the residential part is 226 m 2. Area of the commercial part amounts to 250 m 2. Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 4

Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 5

BUILDING DESCRIPTION AND IT'S ENERGY DEMANDS Number of levels / floors: Po+Pr+2  Basement: at the level m - Business premises 1, restaurant with kitchen  Ground floor: at the level ± Business premises 2, restaurant, Business premises 3 and 4 (shops) with the side entrance  First floor: at the level m - Apartment  Second floor: at the level m – Apartment  Flat roof: at the level m Finished in February 2010; Firs use in April 2010 Energy demands of the site are shown in the table Design Load [W] Fan coil Apart- ments Fan coil shops Fan coil restaura nt Air handling unit (ground floor) Air handling unit (basement) Total Load [W] -5°C 100% -18°C 50% -5°C 100% -18°C 50% Heating Cooling Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 6

Calculation of the heat load was made for the following design conditions:  External design temperature in winter: - 18ºC  External design temperature in summer: +33ºC  Number of hours during the year with the temperature lower than - 5ºC is 97 h  Number of hours during the year with the temperature higher than +30ºC is 77 h  Minimum temperature during the measuring period is - 12ºC  Maximum temperature during the measuring period is +37ºC Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 7

TECHNICAL SITE CHARACTERISTICS  The building has a surface area of 500 m².  The installation comprises two water to water reversible heat pumps which feed a network of 2-pipe fan coils and air handling units for space heating and cooling. All day operation.  The well comprises one variable speed boring pumps with a maximum flow rate of 12 m³/h.  The building was constructed in 2009 and 2010 of quality construction material, with the 12 cm thick thermal insulation of the roof surfaces.  Windows are made of aluminum and lined with wood on the inside. Double glasses are filled with argon.  Heating required from - 12ºC to +18ºC.  Cooling required from +21ºC to +37ºC.  Indoor temperature - all year +24ºC. Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 8

Load profile for apartments – summer and winter Heating not required over 18ºC ambient temperature Design data in summer: 17 kW at 12/8ºC 33ºC ambient Design data in winter: 13 kW at 35/40ºC 0ºC ambient 21 kW at 35/40ºC -12ºC ambient 24 kW at 35/40ºC -18ºC ambient Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 9

Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 10

APARTMENTS In the roof area of the building, at two levels, two residential units are located. No forced ventilation of apartments is foreseen, except air-extraction from the kitchen and sanitary areas. For elimination of heat gains and losses, a 2-pipe system with parapet fan coils is foreseen. Piping is made of copper tubes. Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 11

FIRST FLOOR APARTMANT Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 12

SECOND FLOOR APARTMANT Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 13

HEATING AND COOLING (HVAC) SUB-STATION HVAC sub-station is located in the basement of the building. It accommodates a system which integrated plate heat exchanger, reversible heat pumps, circulating pumps, supplement pumps, thermometers, pressure gauges, various of sensors, pipeline, valves and control unit. Shallow ground water is used as the heat source for the operation of heat pumps. Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 14

Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 15

DESCRIPTION OF THE HVAC SYSTEM The system for preparation of hot and cold water consists of:  Two reversible heat pumps (water-to-water), manufactured by RHOSS, type THHE 135 and THHE 140,  Dismountable plate heat exchanger, manufactured by Euroheat- Kragujevac,  Variable speed boring pump, of the rated power 1.1 kW, measured 780 W,  Four water circulating pumps. Each heat pump has two circulating pumps: one in the secondary circuit of the joint dismountable plate heat exchanger, where the heat exchange with the well water is performed, measured power of 270 W, and one in the supply circuit (fan coil units), measured power of 600 W. Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 16

Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 17

Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 18

The tables show technical characteristics of THHE 135 heat pump. It can be noticed that for the realistic operation conditions the coefficient of performance, COP, is high and amounts to:  For the heat pump THHE 135 …………………..COP = 4.15  For the heat pump THHE 140 …………………..COP = 4.1 Calculation of the COP coefficient does not include the power of pumps required for water circulation. If the calculation would encompass all pumps which are significant consumers of electricity besides the compressor, then COP > 3.7 Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 19

Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 20

The well water flow through the primary circuit of the dismountable plate heat exchanger is provided by a boring pump. The pump has a variable speed drive and is positioned at the depth of -32 m with respect to the soil level. The measured temperature of the well water is higher than 15ºC. The boring pump is switched on after the start of the compressor of any heat pump, and switched off upon stopping of their operation. The circulating pump enabling water circulation in the secondary circuit of the plate heat exchanger towards the heat pump, both in the heating and in the cooling mode is activated just before the start of the heat pump compressor and continues to operate for a while after the compressor is switched off. The circulating pump enabling water circulation towards the consumers both in the heating and in the cooling mode is activated after switching-on of the heat pump and operates until it is switched off, irrespective of whether the compressor is activated or not. Besides the heat pumps the circulating pump is the greatest electricity consumer, as it operates continuously, 10 month 24 hours a day. Its monthly energy consumption approximates 450 kWh. Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 21

Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 22

Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 23

Costs of power supply for the HVAC system The HVAC system was commissioned at the beginning of February The Investor requested to have the possibility to monitor the consumption of electricity for air-conditioning and thus all consumers situated in the HVAC sub-station; heat pumps, water circulation pumps, well pump and local automatic equipment were connected to a separate meter. The consumers in the building were not connected to that meter, like fan coils which are low power consumers. In the first phase of construction only the residential area was completed and corresponding air-conditioning installations for that part were also commissioned. Fan coils in the apartments and towel driers in the bathrooms were connected to the system. The area covered by air-conditioning in the first phase (apartments) is 226 m 2. The apartments are located under the roof and in the part of the building with the glass facade. Thermal insulation of the roof surfaces is 12 cm thick. Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 24

For the first year of operation of the HVAC system, from the beginning of April 2010 until 8 th April 2011, kWh of electricity were consumed In the winter time - heating period, kWh of electricity were consumed In the summer time – cooling period, 4461 kWh of electricity were consumed. The average annual consumption of electricity for heating and cooling was 69 kWh/m 2 The annual cost of the consumed electricity was RSD (€ 890), which is € 4/m 2 Or RSD / month in average (less than € 80/month). Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 25

We have recorded bills for consumed electricity for the complete year which are presented here. The Figure shows the bill for consumed electricity for the period from to Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 26

Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 27

HDD – Heating Degree Day ; CDD – Cooling Degree Day ; base temperature: +18ºC Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 28

TOTAL ENERGY CONSUMPTION = kWh Average annual consumption of electricity for heating is 49 kWh/m 2 Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 29

TOTAL ENERGY CONSUMPTION = 4461 kWh Average annual consumption of electricity for cooling is 20 kWh/m 2 Average annual consumption of electricity for cooling and heating is 69 kWh/m 2 Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 30

Conclusion  With this monitoring, you can observe that the ground water source heat pump is economically efficient and respect the environment,  The average annual consumption of electricity for heating and cooling is 69 kWh/m 2,  We can have better energy efficiency with thicker thermal insulation. The applied 12 cm thermal insulation for the roof surfaces and large glass surfaces on this building are unfavorable and insufficient to meet the new Rules on Energy Efficiency of Buildings, which entered into force in Serbia in October New recommendations define the thickness of 30 to 40 cm for the insulation of roof surfaces,  Energy saving potential for the buildings similar to the one shown here lie in the:  installation of thicker thermal insulation,  installation of three heat pumps of lower capacity,  installation of inverter heat pumps,  monitoring and control of the supplied pumps. Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 31

Thank You For Your Attention QUESTIONS ? Ohrid, 21 May 2013 Slobodan Pejković Monitoring the performance in real-life of ground water source heat pump system in Serbia 32 ECA network and thematic meetings in Ohrid – RAC meeting