The A-Cubed gas absorption heat pump is no more difficult to incorporate into a modern heating system design than any other LZC solution. However, its benefits in terms of carbon reduction are remarkable, offering an unprecedented net efficiency of up to 144% (A7°C, W35°C), gross CV of fuel, after deduction of the parasitic loss. This means it achieves the efficiency level of A+++ under the EuP Directive at these operating temperatures. The A-Cubed uses a gas burner to initiate and sustain a refrigeration cycle, assisted by the available energy from the surrounding ambient air to increase the thermal output. The heat produced can be used to supply low temperature hot water for space heating and/or for the production of domestic hot water via an indirect cylinder, similar to a traditional boiler.