Heat Pump Technologies

Heat pump central heating systems use water or air to transfer heat from the system’s heat distribution centre to other rooms, just like conventional central heating systems. But the heat is obtained from an external ambient source (usually the ground or a water body) using a plastic pipe loop.

Modern heat pump systems use environmentally friendly refrigerants that do not destroy the ozone layer. Industrial alcohol is used as the medium for transferring heat. Fluids circulate in closed loop systems, so there are no emissions into the surrounding ground or water.

A solution containing anti-freeze is circulated round a pipe system to bring heat to the evaporator and heat exchanger where the heat is transferred to another pipe loop containing a refrigerant. The heat energy is then transferred from the refrigerant to a condenser to heat water for the building’s hot water supply or under-floor heating system.

The heat pump itself is powered by electricity, but it only uses a small proportion of the electricity that would be needed to run a comparable electric heating system. Finnish heat pump manufacturers generally use vapor cooling heat transfer units to heat hot water for household use, whereas systems manufactured in other countries more typically heat household water with an electric resistor.

Detached houses in Finland are widely heated using ground source heat pump systems which may obtain heat from the soil, the bedrock, or surface water bodies such as lakes. The water heated by such systems can be used to heat rooms or as the hot water supply. Heat pumps can also extract heat directly from the air, but alternative heating systems must also be installed, since air source systems cannot function when air temperatures fall below -10ºC, which is not unusual in Finland. Air source heat pump systems are most useful in terms of reducing heating costs in the spring and autumn.

Heat pump system types:

• Air source
• Ground source
• Water source