AWARD FOR THE BEST ENERGY EFFECTIVE PROJECT 2008 in Slovenia Optimal use of renewable energy sources for heating and cooling of our office building Optimal use of renewable energy sources for heating and cooling of our office building

Goals of the project: to build business areas for the company to build business areas for the company to build energy effective building, taking into account modern design of the building and contemporary systems of cooling and heating to build energy effective building, taking into account modern design of the building and contemporary systems of cooling and heating use of renewable energy sources use of renewable energy sources use of up-to-date materials at construction use of up-to-date materials at construction to limit the power of Gas-fired boiler under 50kW because of the lower expenses of construction for mechanical room, maintenance and operation to limit the power of Gas-fired boiler under 50kW because of the lower expenses of construction for mechanical room, maintenance and operation to build a reference building for the purpose of promotion of renewable energy sources and efficient use of energy to build a reference building for the purpose of promotion of renewable energy sources and efficient use of energy employee friendly work environment employee friendly work environment

3 years ago:

Today:

Design of the building Reinforced concrete skeleton with a structural glass façade Reinforced concrete skeleton with a structural glass façade Glass surfaces with coloured glazing Glass surfaces with coloured glazing Use of renewable energy sources and efficient use of energy Use of renewable energy sources and efficient use of energy Effective ventilation with recuperation Effective ventilation with recuperation Concrete core heating Concrete core heating Heat-insulated parapets Heat-insulated parapets Use of glass foam - Technopor Use of glass foam - Technopor for insulation for insulation Exterior shading Exterior shading

Heating and cooling scheme Legend Legend 1.Ground probe 2.Heat pump (Brine/Water) 3.Hot water storage cylinder 4.Cold water storage cylinder 5.Sanitary water cylinder 6.Gas-fired condensing boiler 7.Air conditioning device A.Radiators B.Floor heating C.Convectors D.Temperation of concrete mass

Heating of the building Heating with heat pump. Support to the heating with Gas-fired condensing boiler. Air temperation and ventilation with air conditioning with recuperation up to 80%. Accumulation in concrete core.

Cooling of the building Cooling with heat pump. Air temperation and ventilation with air- conditioning with recuperation up to 75%. Accumulation in concrete core.

Passive cooling Passive cooling directly from ground probe. Operation of circulation pumps. Alternation through air conditioning device. Recuperation according to the difference between the outdoor and indoor temperature. Accumulation of cool energy in concrete core.

Investment & costs Energ. eff. construction Trad. construction Investment for heating & cooling € € Gas boiler house with equipment € Ground probe with equipment € Together € € Difference in the investment € Heat loss from the building kWh kWh Use of gas for heating Sm3 Heat gain of the building kWh kWh Use of electricity for cooling (έ = 2,6) kWh

Savings and investment return period Heating – winter 2006/07 Heat pump, Gas-fired condensing boiler Yearly use of heating energy according to the calculation kWh Actual measured values Use of primary energy sources for heating kWh € Gained heating energy kWh Used energy and gained energy ratio 2,66 Savings at energy effective construction kWh4.049 € Cooling - summer 2007 Heat pump, passive cooling Yearly use of cooling energy according to calculation kWh Actual measured values Use of primary energy sources for heating kWh 178 € Gained cooling energy kWh Used energy and gained energy ratio 6,58 Savings at energy effective construction kWh € Savings - season 2006/ kWh5.189 € Investment return period 7,35 year

Specific use of energy Heating Specific use of the old building 151,0 kWh/m2 Specific use of the old building 151,0 kWh/m2 Specific use of the new building without renew.sour. 82,1 kWh/m2 Specific use of the new building without renew.sour. 82,1 kWh/m2 Specific use of the new building with renew.sour. 26,7 kWh/m2 Specific use of the new building with renew.sour. 26,7 kWh/m2 Actual specific use of energy measured in ,0 kWh/m2 Actual specific use of energy measured in ,0 kWh/m2Cooling Specific use of the old building No cooling Specific use of the old building No cooling Specific use of the new building without renew.sour. 21,9 kWh/m2 Specific use of the new building without renew.sour. 21,9 kWh/m2 Specific use of the new building with renew.sour. 3,35 kWh/m2 Specific use of the new building with renew.sour. 3,35 kWh/m2 Actual specific use of energy measured in ,48 kWh/m2 Actual specific use of energy measured in ,48 kWh/m2

Conclusion For heating, cooling and ventilation we need only 1/3 of primary energy sources compared to conventional heating and cooling system. For heating, cooling and ventilation we need only 1/3 of primary energy sources compared to conventional heating and cooling system. Loss of warmth is covered by heat pump with the power of 39,5 kW, except in peak times. That represents only 1/3 of the power calculated for conventional heating. Loss of warmth is covered by heat pump with the power of 39,5 kW, except in peak times. That represents only 1/3 of the power calculated for conventional heating. For cooling we cover up to 80 % needs with geothermal energy through ground probes with passive cooling, the rest comes from the heat pump. For cooling we cover up to 80 % needs with geothermal energy through ground probes with passive cooling, the rest comes from the heat pump. Apart from the described energy-saving effects, which has reduced primary energy needs from kWh to kWh a year, this project has considerable environmental effects, reducing CO2 emissions by 20 tons a year and CO in NOx by 35 kg a year. Apart from the described energy-saving effects, which has reduced primary energy needs from kWh to kWh a year, this project has considerable environmental effects, reducing CO2 emissions by 20 tons a year and CO in NOx by 35 kg a year.

Use of renewable energy sources for heating and cooling in the office building Project was realized by: INVESTOR: Kostak d.d. Božidar Resnik, B. Sc. Mech. Eng. - project manager Željko Horvat, B. Sc. Civ. Eng.- project co-ordinator Biljana Šepetavc, B. A. Civ. Eng. - construction manager PROJECT ENGINEERING: Savaprojekt d.d. Tina Božičnik, B. Sc. Arch. - architecture of the building Goran Šalamon, B. Sc. Civ. Eng. - construction of the building Mitja Lisec, B. Sc. El. Eng. - electro installations Bahč d.o.o. Edo Bahč, B. Sc. Mech. Eng. - mechanical installation project