Gas Heat Pumps

Solution advantages

  • Links efficient technologies of condensing boiler and heat pump
  • Maximising use of fuel and renewable energy
  • Suitable for low temperature heating systems, for new and existing buildings

Maximum efficiency with natural gas by using renewable energies

The gas-fired heat pump combines high efficiency gas-fired condensing technology with environmental heat. In this way, renewable energy can be used relatively easily for heat supply to new and existing buildings. The gas-fired heat pump systems are classified into compression, absorption and adsorption systems according to their ways of working.

Gas-fired compression heat pumps

The functional principle corresponds to that of the conventional compression heat pumps: The devices are driven by a combustion engine and additionally utilise the waste heat of the engine.

Gas-fired adsorption heat pumps

Gas-fired adsorption heat pumps operate under vacuum: The refrigerant water vaporises in a closed container, where it is adsorbed, desorbed and liquefied again. Besides the refrigerant water, the environmentally friendly mineral zeolite is also present in the tank. The actual process takes place in two sub-steps. First, the water is evaporated with free heat from the environment and then absorbed by the zeolite. The heat released by adsorption is used directly for heating purposes. Then the water is expelled (desorbed) again from the sorbent with the help of the gas burner and then condensed. Through condensation, the water also delivers the “saved” environmental heat to the heating system. Then the process can start all over again. Compact gas-fired adsorption heat pumps made of a sorption module and a gas-fired condensing module: The condensing module drives the sorption process and covers the peak load of the heating system. The compact gas-fired adsorption heat pumps have a modulation range from 1.5 to 16 kW. They are particularly efficient in low temperature heating systems. The environmental heat is extracted from the soil, the air or solar radiation. 

Gas-fired absorption heat pumps

The gas-fired absorption heat pump operates at excess pressure: Besides the refrigerant, another liquid medium with the absorbent is contained as a solvent. The gas-fired absorption heat pump has a thermal compressor, which consists of the absorber, the solution pump, the generator and the pressure reducing valve. The thermal compression runs continuously in four sub-steps: In the absorber, the refrigerant is absorbed at a low pressure and low temperature by the solvent. The result is a “rich” solution with a high refrigerant content. It is transferred from the solution pump to the generator and heated there with a gas burner. As a result, refrigerant vapour escapes at elevated pressure and is fed to the condenser. The remaining “poor” solution with low refrigerant content flows through a pressure reducing valve back into the absorber where it is cooled. As with compression heat pumps, the environmental heat is absorbed in the refrigerant evaporator and delivered to the condenser. Compact gas-fired absorption heat pumps cover a power range from 20 to 40 kW and can be interconnected to form cascades. They are also used especially in low temperature heating systems. The environmental heat is extracted from the soil, the air or solar radiation. 

Gas absorbtion heat pump
Gas absorbtion heat pump