Town hall of Pylaia
The heating and cooling demands of Pylaia Town Hall in Thessaloniki -total area 2500 m2- are totally covered by eleven (11) geothermal heat pumps with a diesel boiler and a cooling tower as back up. The heat pumps are water-to-water type fed by water circulating in a field of ground heat exchangers comprising 21 wells, 80 meters deep.
| Country | Greece |
| City | Thessaloniki |
| Client name | Pylaia Town Hall |
| Application area | Building sector |
| Building type | Public building |
| Year of construction | 2001 |
| Heat source/sink | Water/Water |
| Heat pump type | Electric heat pump |
| Year of installation | 2002 |
| Purpose | Heating and cooling |
| Heat source system | Borehole heat exchanger (vertical) |
| Operation mode | Bivalent |
| Refrigerant | R22 |
| Contact name | Ms Anastasia Benou (Centre for Renewable Energy Sources - CRES) |
| Contact E-mail | abenou@cres.gr |
| Contact website | http://www.cres.gr |
| Supported by | CRES - Ministry of Development |
Project description
Building, overall energy concept
The office building of total area 2500 m2 with 3 storeys is situated in Pylaia, Thessaloniki. The office building was constructed in 2001.
Photo 1: Office building of Pylaia Town Hall
The geothermal system comprising Borehole Heat Exchangers was installed in 2002 in order to cover totally its heating/cooling loads.
The heating/cooling distribution system into the building consists of fan-coil units (FCU) and an air handling unit.
There are also a diesel boiler and a cooling tower as back up.
Heat pump system
The eleven (11) ground heat pumps (water-to-water) operate in bivalent -heating and cooling- mode with electric energy.
The geothermal heat pump system operates with the use of borehole heat exchangers and uses de-ionized water.
The heat pumps use R22 as refrigerant.
The system -both for heating and cooling mode- uses the ground as heat source or sink.
The heating and cooling capacity of the geothermal system is Pth=265kW/Pc=280kW.
Photo 2: Basement with heat pumps at Pylaia Town Hall office building
Operation experiences
Not available
Costs, economic efficiency, incentives
The total investment cost of heat pump system was 161.410 €.
Given that the cost of electricity was 0,1€/kWh and the cost of oil is 0,6€/lt, simple pay-back time is calculated below.
Heating/cooling demands are estimated at about 576.216kWhth/168.000kWhc.
Given that COP for heating/cooling are:
• COPth=4
• COPc=11,94
Total operational cost of the heat pump system for heating and cooling is 19.205€.
Total operational cost of the conventional system for heating and cooling is 47.394€.
Maintenance costs are estimated as following:
• geothermal system: 1,2% x capital cost = 1.937€
• conventional system: 3% x capital cost = 4.155€
According to the aforementioned calculations, simple pay-back time is estimated to 0,8y with an expected life-time of the system of 30y.
The project was financially supported by Center for Renewable Energy Sources (CRES)/Ministry of Development(100%).
Regulations, guidelines, benchmarking
Not available
References
- Mendrinos D., Karagiorgas M. and Karytsas C., (2002). ‘Use of Geothermal Heat Pumps for Heating of Buildings in Greece', OPET - Low Temperature Systems in Existing/Historical Buildings Workshop (OPET - LowExx Workshop), March 2002, Maastricht, the Netherlands.
- Kyriakis N., Michopoulos A. and Pattas K. (2003). ‘Ground Heat Exchanger of Pylaia. Energy Evaluation after the First Year of Operation', Tech. Chron. Sci. J. TCG, IV, No 1-2.
| Design value | Measured data | |
|---|---|---|
| Year | 2002 | 2003 |
| Heating capacity (kW) | 265,0 | |
| Cooling capacity (kW) | 280,0 | |
| COP (Heating, appliance)1 | 4,0 | 2,9 (-5°C) - 4,8 (20°C) |
| EER (Cooling, appliance)2 | 11,94 | 16,38 (20°C) - 7,85 (43°C) |
| SPF (Heating)3 | 4,0 | |
| SEER (Cooling)4 | 3,5 |
1 COP range during the first year operation (2003)
2 COP range during the first year operation (2003)
3 SPF for the heat pumps only, measurements by Aristotle University of Thessaloniki during the first year of operation.
4 SEER for the heat pumps only, measurements by Aristotle University of Thessaloniki during the first year of operation.
| Institution/Company | Centre for Renewable Energy Sources and saving (CRES) |
| Responsibility/Function | information provider |
| Street/PoBox | 19th Marathonos ave |
| ZIP | 19009 |
| City | Pikermi, Athens |
| Country | Greece |
| Contact Person | Mr. D. Mendrinos |
| dmendrin@cres.gr | |
| Website (URL) | http://www.cres.gr |
