Air Water Heat PumpsOur air to water heat pumps provide central heating by means of a vapour compression cycle.  Just as your fridge uses a refrigerant to extract heat from the inside of your fridge to keep your food cool, our air to water heat pumps extract heat from the air outside and use it as a source of heating for your home through, radiators, underfloor systems and they can even can provide domestic hot water.



Our air to water heat pumps have four main parts:

  • Evaporator
  • Compressor
  • Condenser (Heat Exchanger)
  • Expansion vessel
  1. The evaporator collects heat from the outside air which is then drawn into the unit by the fan. This air is drawn over the evaporator fins and leaves through the front grille. The evaporator has a liquid refrigerant passing through it which boils at -23 degrees.  The air gives up its heat to the refrigerant which in turn vaporises.
  2. The preheated vapour now travels to the compressor which under compression raises to an even higher temperature.
  3. The hot vapour now enters the condenser where it is surrounded by water from the heating system. The heat is passed to the cooler water and the now cooler refrigerant returns to its former liquid state but is still under pressure from the compressor.
  4. This high pressure is then released by passing the liquid through the expansion device and from there it returns to the evaporator and the cycle starts again.

Applications and uses For Heat Pumps:

Underfloor Heating:

Underfloor heating uses the benefit of radiant rising heat and relatively low water flow temperatures to heat the floor surface.  The heat is distributed evenly and is absorbed by the structure of the building and objects in the room.  The result is an efficient heating system with reduced running costs and lower carbon emissions, making this the ideal match for our air to water heat pump.


Central heating radiators:

Our air to water heat pump can also be used with radiators.  The sizing of the radiator systems uses different methodology to that of fossil fuel systems. This is due to the lower water temperature typically used in the system design. We recommend a temperature of between 45°C and 50°C be utilised when using our air to water heat pumps.

You may well ask yourself why air to water heat pumps have become so popular. It is as a result of EU leaders endorsing an integrated approach to climate and energy policy in March 2007. The aim of the agreement was to combat climate change and increase the EU’S energy security while strengthening its competitiveness.

The EU’Leaders set a series of demanding climate and energy targets to be met by 2020, known as the “20-20-20” targets.

These are:

  • A Reduction in EU greenhouse gas emissions by at least 20% below the 1990 levels.
  • 20% of energy consumption to come from renewable resource
  • A 20% reduction in primary energy use compared with projected levels, to be achieved by improving energy efficiency.

As a form of renewable energy, our air to water heat pumps address the need for increased use of renewable energy.