This paper describes a chemical storage device combined with a vapour recompression system designed to operate using the cheap rate ＇＇Economy 7＇＇ electricity tariff. The rotary storage device employs process intensification which exploits centrifugal fields. The heat pump uses exhaust air from a ventilation system, in which fresh air is supplied via a sunspace of a house, as its main heat source. The heat pump has been analysed thermodynamically using various refrigerant/absorbent combinations.