Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.
Due to limited natural resources exploited for heating and in
order to reduce the environmental impact people should strive
to use renewable energy sources. Heat pumps allow the
conversion of ambient heat, available in almost unlimited
quantities, to heating energy. The paper describes an energysaving
house provided with good thermal insulation and heated
by an air-to-water split type heat pump. The paper also presents
the calculation of the heat pump thermal efficiency.
The condenser is located in the attic and evaporator in the
boiler room of the house. The house heating up to the ambient
temperature of 0ºC was provided by an air-to-water heat pump
and a condensing oil heating furnace if the ambient temperature
dropped to below 0ºC. The results of the nine-year testing
showed that the heat pump was used during most of the heating
season. The average coefficient of performance (COP) of the
air-to-water heat pump in nine heating seasons was 3.16,
indicating that over 68% of the heat was obtained from the
ambient air. The comparison between COP of air-to-water heat
pumps in energy-saving house and of water-to-water heat
pumps fitted in houses dealt with under other projects indicates
that water-to-water heat pumps have higher COPs. The heat
pumps obtaining heat from groundwater, thus being capable of
operating throughout the heating season, have the highest COP.
The advantage of an air-to-water heat pump, however, lies in its
simple design and a wide range of applications.
In comparison with the furnace the heat pump yielded
considerable saving in fuel and money, which justifies its home
heating application in the Central European climatic area.