Gas heat pumps

Highly efficient renewable heating

A gas heat pump is a heating appliance which uses the renewable energy stored in the soil, groundwater or the environment for heating purposes. It then  combines this environmental heat with high efficiency gas-fired condensing technology.

In this way, renewable energy can be used relatively easily for heat supply to new and existing buildings.

There are three types of gas heat pumps: a gas-fired compression heat pump, a gas-fired adsorption heat pump and a gas-fired absorption heat pump.

Gas-fired compression heat pumps

A gas-fired compression heat pump operates like a refrigerator in reverse: a refrigerant extracts low-temperature heat from the environment, which causes the refrigerant in the system to evaporate; the refrigerant is then compressed by a natural gas engine; heat is released in a condenser and is transferred to the water circulating in the heating system.

The gas-fired compression heat pump efficiency is increased thanks to heat recovery from the engine and exhaust gas.

Gas-fired compression heat pumps are especially suited for commercial buildings – such as hotels, hospitals or schools – and large housings to produce heating, cooling and domestic hot water.

Gas-fired adsorption heat pumps

A gas-fired adsorption heat pump captures the heat from the environment (soil / solar) and stores it in refrigerant liquid water. This water is then captured by environmentally friendly mineral zeolite, which releases even more heat. This heat can be used directly for heating purposes.

To allow a new heating cycle, water captured in zeolite is vaporised by gas-fired heat as a second step. Then the process can start all over again.

Gas-fired adsorption heat pumps  are most efficient in low temperature heating systems. They use a natural refrigerant (water), and are easy to maintain (no compressor needed).

Gas-fired absorption heat pumps

A gas-fired absorption heat pump draws in the heat from the environment at low temperature and releases it to the water circuit of the heating system at high temperature. It use a natural refrigerant – such as ammonia with zero ozone depletion potential and zero global warming potential – inside a closed cycle operated by a thermal compressor.

Compact gas-fired absorption heat pumps are most efficient in low temperature heating systems, but are especially suited for existing, retrofit installations with high temperature distribution systems, such as radiators. They are mainly used in industrial or commercial buildings, as well as residential homes to produce heating, cooling and domestic hot water.


  • Links efficient technologies of condensing boiler and heat pump
  • Use of existing energy infrastructure
  • Maximising use of fuel and renewable energy
  • Suitable for low and high temperature heating systems, for new and existing buildings
  • Use of 100% renewable energy, if fully powered by biogas