Air to water heat pumps use outside air to boost the temperature of hot water heating in the home.
How do air to water heat pumps work?
This type of heat pump can be classified as an air source heat pump along with air to air heat pumps. What makes this system different is that it uses the constant energy of the air to heat a wet central heating system. An air to air system in comparison uses outdoor air to heat air within the home.
The air is collected by a fan and air ducts which lead to the heat pump. These devices are connected by pipes containing water and antifreeze, which is there to absorb the heat (energy) from the air. This refrigerant then evaporates in the compressor and is led to the condenser.
As the heated gases meets water from the wet central heating system the gas is cooled and turned back into a liquid. The water in the central heating system is in turn heated up.
Next, the refrigerant is passed through a drying filter. The purpose of this is to collect any moisture from the system. It is then sent back outside to begin the process again.
Product efficiency for this type of pump ranges from around two to three CoP.
The benefits of air to water heat pumps
Air to water heat pumps utilise the energy from the air making them environmentally friendly.
This type of system is very effective and can even obtain heat when outside temperatures are as low as minus 15° C.
This type of system is ideal for underfloor heating as air source heat pumps run more efficiently at a lower temperature than average boilers.
The installation itself is relatively simple and can be done at various properties with either an indoor or an outdoor unit.
Air to water heat pumps are eligible for the Renewable Heat Incentive tariffs which went live on 9 April 2014.
The negatives of air to water heat pumps
Like all heat pumps an air to water heat pump needs electricity to run and also to raise the temperature of instant hot water. This is because heat pumps deliver lower temperatures than gas or oil boilers.
As a result of the lower temperatures over much longer periods, this means that during the winter the air to water heat pump may need to be left on constantly to heat your home efficiently.