Air Source Heat Pumps
Air source heat pumps absorb heat from the outside air. They are the most common type of heat pump installed in the UK. Air-to-air source heat pumps transfer the heat by the air. The main unit is usually sited outside the home, and between one and four indoor units are mounted high on the wall. These indoor units are individually controllable and take the place of radiators.
The heat pump draws heat from the air outside, then uses it to warm to a special liquid called a refrigerant. As the refrigerant warms up, the liquid turns into gas which is compressed to increase its temperature. The heat generated by this process is transferred to a separate body of water which is distributed to a central heating system to warm the house. Once the gas cools down, it becomes liquid again and gets re-used at the start of the cycle.
Case Study: Banham Zoological Gardens in Norfolk
Set in 50 acres, Banham zoological garden in Norfolk is run by the Zoological Society of East Anglia. The zoo is keeping inhabitants of its Tropical House warm using air source heat pumps.
The heat pump’s fan unit located outside the Tropical House works by taking energy from the air to heat water which is used for Tropical House’s underfloor heating and air distribution units mounted in the ceiling. The system is ideal as the heat pump runs in long cycles which maintain a steady temperature.
By installing the air source heat pump system, Banham zoological garden has been able to efficiently heat Tropical House all year round. The system uses 70% less energy than an oil boiler, has reduced heating bills, made significant impact on reducing carbon emissions, having saved an estimated 170 tonnes of C02 since its installation when compared to an oil boiler.