| Abstract [eng] |
The aim of this master thesis is to analyse heat pumps to use them more efficient and to increase their applicability in public buildings in small towns. In Lithuania, one of the most popular heating methods for public buildings is district heating, due to economic and ecological aspects. However, not all smaller settlements and villages in Lithuania are equipped with heat network infrastructure, so heat pumps could be an excellent alternative to solid fuel boilers, which use polluting fuels and require permanent maintenance staff. The most popular “air to water” heat pumps on the market today have lower installation costs and require less installation space compared to “ground to water” and “water to water” heat pumps. However, the efficiency of these types of heat pumps decreases as the outdoor air temperature drops. “Ground to water” and “water to water” heat pumps are more efficient, with SCOP values of 5.6 or more, and geothermal boreholes have a lifetime of up to 50 years but require a higher investment for installation. Two energy efficient science buildings, class A+ and class B, were selected as the subject of the study. An analysis of the efficiency of the heat pumps as well as an environmental and economic analysis with the additional inclusion of district heating was carried out. The results of the study show that using heat pumps in combination with solar electricity is the best choice from an economic and environmental point of view. In public buildings, geothermal heating is up to 30-47 % more efficient with solar power, depending on the energy efficiency class of the building, with up to 32 % less CO2 emissions, but with a total 20-year cost of heating of the building up to 5 % more than “air to water” heat pumps. |
