Project summary

*) Aperture area = light transmitting area of the front glass**) measured, between storage and piping to taps (solar system output)***) related to the measured output mentioned before

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Župnijska cerkev Petra in PavlaZagorje ob Savi

Slovenia

DescriptionParish church in Zagorje ob Savi was build in 1874, mainly from the stones. Because of static problems the renovation began in the year 2000. Besides others the renovation includes the protection of constructions and interior, which were in bad conditions due to the high content of water in the construc-tions and high air humidity. According to the good experience with low temperature walls heating in the church in Mokronog (in SE part of Slovenia) the same system was chosen. Tubes were installed in outer walls up to 80 cm over the floor level. Solar system consists of 32 m2 of vacuum flat solar collec-tors and a 2 m3 heat storage. In parallel to the solar system, a gas boiler is installed. The system is used only for heating of the church and it operates through the whole year while back-up gas boiler operates only from the end of October to the March.

Mr. Matjaž Križnar, priest at Župnijska cerkev Sv. Petra in Sv. Pavla: „The combination of low temperature heating and solar heating enables great advan-tages compared to other systems. The system ef-ficiently improves indoor

conditions, protects the interior and runs from March to November without any ad-ditional cost. Although the exact amount of heat collected with solar system is unknown, the consumption of energy for heating the church is much lower then in other compara-ble churches. Such systems can be multiplied in number of other churches.“

Owner and operatorRoman Catholic Church, Parish church Župnijska cerkev Sv. Petra in Sv. PavlaG. Matjaž KrižnarCankarjev trg 31410 Zagorje, SloveniaPhone: +386 31 689970Matjaz.kriznar@rkc.si

BuildingType of building ChurchNumber of users / dwellings, floors ./.Year of construction 1874 (2000–2005)Total effective area (heated) ./. m2

Hot tap water consumption (source) ./. m3/a,Whole energy consumption for heating

purpose after CSTS implementation60,500 kWh/a

System engineeringYear of construction of CSTS 2002Type of collectors Flat vacuum collec-

tors with vacuum pump

Thermal power 22 kWtherm

Aperture area of collectors*) 32 m2

Buffer storage 2 m3

Hot tap water storage ./. m3

Total capacity of boilers (natural gas) 39 kWType of hot tap water heating ./.Type of heating system Centralised

CostsTotal cost solar system 14,500 EuroCost of CSTS / gross area of collectors 422 Euro/m2

Subsidies 0 %

OutputOutput of solar heat**) not yet availableReduction of final energy***) not yet availableCO2-emissions avoided ./.Solar performance guarantee No

Technical description

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Description of the CSTSYear of construction of CSTS 2002Thermal power 22.4 kWtherm.

Gross area of collectors 34.4 m2

Aperture area of collectors 32.0 m2

Type of collectors Flat vacuum collectors with vacuum pumpType of assembly Roof topOrientation of collectors South (°)Inclination angle to horizon 32°Freezing protection GlycolOverheating protection Expansion vesselOperation mode High flowUse of CSTS for Thermal activation of the walls and heating of the churchBuffer storage 2.0 m3 (one storage tank)Hot tap water storage ./. m3 (heating system only)Control of backup-system / CSTS Separated control

Župnijska cerkev Petra in PavlaZagorje ob Savi

Slovenia

Technical description (2)

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Župnijska cerkev Petra in PavlaZagorje ob Savi

Slovenia

Hot tap water systemType of hot water heating

Hot tap water is not provided in this object.

Recirculation systemFor decentralised systems:

The installation on the consumer siteSize of storage for hot tap waterSpecification

Space heating systemType of heating system CentralisedNumber of boilers 1Total capacity (power output) of boilers 39 kWCapacity of each boiler and the

year of constructionNo. 1: 39 kW (2002)

Energy source Natural gasType of boiler system Low temperature

Type of operationOperator of the CSTS system Self-operationCSTS monitoring NoData accessible via internet NoScientific monitoring / follow up NoMaintenance contract Yes: once a yearVisualisation of the solar heat output No

Yield of CSTS plantOutput of solar heat not yet availableOrigin of data ./.Measuring point ./.Reduction of final energy The church was not

heated before res-toration

Origin of data ./.Solar performance guarantee No

Heat consumptionWhole energy consumption for heating

purposes after CSTS implementation60,500 kWh/a

Origin of data MeasuredEnergy used for Space heatingWhole energy consumption for heating

purposes before CSTS implementationThe church was not heated before res-toration

Total tap water consumption 0 m3/aHot tap water consumption 0 m3/a,Hot tap water temperature ./.Cold water temperature ./.

SummarySolar system is used for thermal activation of church walls through the whole year. It consist of a 32 m2 large field of solar collectors. A plate heat exchanger is installed between solar collectors and heat storage with a volume of 2 m3. The gas boiler is connected parallel to the heat storage and it is used only between the end of October till March. Parallel tubes are built in outer walls up to 80 cm above the floor. 40 tube loops are used, divided in 4 groups.The main advantages of thermal activation of outer walls are: no problems with wet constructions, protection of paintings and wood interior and much better indoor environment.

Financing & Investment

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Župnijska cerkev Petra in PavlaZagorje ob Savi

Slovenia

Financing of CSTSForm of financing PurchaseDistribution in percentage 0 %

Costs of solar materialsTotal cost of solar system 14,500 EuroDetailed costs for

Collectors n. a. EuroElevation / mounting structure n. a. EuroStorage / heat exchanger n. a. EuroBackup heater n. a. EuroControl n. a. EuroInstallation n. a. EuroPlanning / Engineering n. a. EuroOthers n. a. Euro

Operation costs of heating systemPower cost for pumping n. a. Euro/aMaintenance cost n. a. Euro/aMonitoring cost n. a. Euro/aOther operation cost n. a. Euro/aTotal operation cost n. a. Euro/aOr: Increase of operation cost after

CSTS implementationn. a. Euro/a

IntroductionThe heating and the solar systems were financed by many individual donators and they were build during the urgent renovation process. Therefore the costs of the bought systems were lower because no additional investments for installing the systems in the building were needed.

many individual donators<

Development & Experiences

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Župnijska cerkev Petra in PavlaZagorje ob Savi

Slovenia

Experiences managementExperience problems or failures? Yes: once per year

(at the start of the heating season) the vacuum pump must be used for reduc-ing the pressure in flat solar collectors; during the sum-mer the pressure is higher, but this is some kind of ad-ditional overheating protection.

Find solutions to these problems or failures? Yes

Financial effects / project performanceProject economically efficient? YesFiscal or other financial effects? n. a.Effects on rental fees? No

Experiences technical staffExperience problems or failures? n. a.Find solutions to these problems or failures? n. a.

Summary of experiences / Notices to the project performanceThe combination of low temperature heating and solar heating enables great advantages compared to other systems. The system effi-ciently improves indoor conditions, protects the interior and runs between March and November without any additional cost. Although the exact amount of heat collected with solar system is unknown, the consump-tion of energy for heating the church is much lower then in other comparable churches. Such system can be multiplied in a number of other churches.