a hot water supply apparatus comprises a thermodynamic circuit having a compressor , a condensor for heat exchange between the thermodynamic fluid in the circuit and a high temperature source . that circuit further includes an evaporator arranged for heat exchange with a non - freezable heat carrying fluid which is circulated in a solar energy collecting circuit . a tank receives a body of water for heat storage . an heat exchanger is arranged in the circuit for circulation of the heat carrying fluid and is physically located above the tank . it may be combined with the evaporator . a pump directs a flow of water from the storage tank to sprinkling means associated with the heat exchanger whereby the apparatus operates as ice manufacturing device under severe cold conditions , when there is insufficient heating energy available from the sun .