The project was carried out in order to increase the energy efficiency in heating at two primary schools (Primary school Kratka, Primary school Horna) in Sala, in south west Slovakia. Both school buildings are heated by District heating system. There are caretakers flat in the school buildings and because of this the whole buildings had to be fully heated also during free days (Saturdays, Sundays, holidays). After disconnecting the caretaker's flats from the heating of the schools, installing independent boilers in these flats and installing automatic regulation of heating, the school buildings would only be tempered during free days and the heat supply would also decrease after end of classes during the week. By this measure both schools are able to decrease their heat consumption by 10%.

End User Area - Refurbishment of buildings
Target Audience - Schools and Universities
Technical - Energy Efficiency, Heating

Context

Caretakers' flats were built as a part of the school buildings, so they had joint heating. It was not a problem in the past when the cost of heat was very low, but nowadays when the cost of heat takes a majority of school budget this is a weight for school management. On the ground of a caretaker's flat school building has to be fully heated during Saturdays, Sundays and holidays. Energy audit of Primary schools Kratka and Horna in Sala, which were processed by Regional Energy Agency Sala – Galanta (REA), suggested as a first measure to disconnect a caretakers' flats from school heating and install an automatic control system at heating which would decrease temperature in school building during free days.

Objectives

The direct objective of the project was an installation of automatic regulation of heating which would decrease temperature in school building during free days. This was possible after disconnecting of caretaker's flat from school heating. Short-term objective of the project was increase energy efficiency of school heating and to save money from school budget, which can be used on other things necessary for schools. Long-term objective is to stimulate implementation measures, which can increase efficiency of heating systems.

Process

REA Sala-Galanta focused according its program on schools, which are high users of energy and particularly of heat. School department at Municipal Office Sala chose Primary schools Kratka and Horna, which have the highest heat consumption, to work with. Both schools are heated by District heating system.

Energy audits of these schools were carried out by REA, in co-operation with Slovak Technical University, Faculty of Civil Engineering, Department of building services. Energy audits suggested as a first measure to disconnect a caretakers' flats from school heating and install an automatic control system at heating which would decrease temperature in school building during free days. The independent boiler has to be installed in caretaker's flat at the same time. The annual heat consumption is 3000 GJ at Primary school Horna and 2920 GJ at Primary school Kratka. After implementation of this measure 10% of heat consumption can be saved. The pay back of this project is 2 years. Municipal office Sala decided to realize this measure and asked REA to work out implementation project of independent heating of caretaker's flat. REA processed this project again in co-operation with Slovak Technical University, Faculty of Civil Engineering. Implementation project of automatic regulation was worked out by MENERT LLC. Realization was done by MENERT LLC. The independent boiler (with heat power 22 kW) was installed in caretaker's flat. The flat was disconnected from school heating. The automatic regulation was installed in school heating. School building can be now only tempered during free days and caretakers flat is fully heated at the same time.

Financial resources and partners

Investment cost into project of reconstruction of heating at Primary schools Kratka and Horna was 12000 Euro. Payback period is 2 years calculated using current cost of heat in Sala. The annual heat consumption of both schools is approximately 6000 GJ. Now 10% can be saved, that means 600 GJ per year.

Project partners:
Municipal Office Sala
MENERT LLC.
Slovak Technical University , Faculty of Civil Engineering, Department of building services

Results

A major benefit of this project is 10 % decrease of heat consumption at both schools. That means 600 GJ of heat will be saved. In other words 21 253 m3 of natural gas will be saved in District heating plant which supplies heat into both schools. By implementation of this project 41 tons of CO2 emissions is saved yearly. Moreover each school can save now approximately 175 000 SKK This amount of money can be now used for purchase of school material.

The project is possible to repeat at every school which has a caretaker's flat heated by school heating. The heat saving after disconnecting a caretaker's flat from school heating is approximately 10 % from previous consumption.

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