16 Bedford Road

Lower Stondon



SG16 6EA

Tel: 01462 815756

Fax: 01462 819578

What is a heat pump?

A heat pump is a refrigerant based system (like your refrigerator at home but in reverse). The system can absorb low grade heat from the air (air source), water (water source) or ground (ground source), and raise its temperature efficiently to be suitable for space heating and/or hot water.

A heat pump absorbs free energy (heat) from a low-temperature source (air, water or ground) and upgrades it to a higher temperature, via the refrigerant cycle. Heat pump efficiencies range from 3:1 to 5:1 (300-500%) i.e for each 1kW of electricity consumed between 3kW – 5kW of heat energy can be absorbed and transferred. By contrast, conventional fossil fuel boilers produce less heat output, about 0.85kW for every kW consumed, therefore heat pumps are more cost effective, eco-friendly and use renewable energy for the greater good of our environment.

  1. The heat pump is based on refrigerant cycle and basically comprises of 4 essential components.
  2. The Evaporator - absorbs heat from renewable source (air, water, ground)DX-Cycle
  3. The Compressor - raises pressure hence temperatures of absorbed heat
  4. The Condenser - rejects upgraded heat to the source inside (air or water)
  5. The Expansion Device - reduces pressure/temperature to allow evaporation (heat absorption) at low temperatures.

The refrigeration cycle is used also in supermarkets, Air conditioning system, Cold store, Car air-conditioning (Climate control), Central air-conditioning systems etc.

Daikin Altherma is an air source, air-to-water heat pump system specifically designed for domestic central heating.

It can provide water temperature up to 50°C (without backup electric heater) in ambient temperatures as low as -15°C with very high seasonal efficiency of up to 450%.


House Refrigerator / Freezer uses refrigerant cycle as describe above.