A TEMPERATURE CONTROL SYSTEM

A temperature control system (10) for controlling the temperature of liquid within a reservoir, comprises a heat collector (12), a reservoir (14), and a heat transfer liquid recirculation system (16). A heat transfer liquid recirculation system (16) includes a series of collector heat transfer tubes (30) and a series of reservoir heat transfer tubes (32) both designed to carry the heat transfer liquid. The reservoir wall and/or floor is formed of a water impervious layer (18), a first heat conductive layer (20), an insulating layer (22), and a supporting layer (24). A plurality of capsules (26) containing phase change substance and reservoir heat transfer tubes are set adjacent to each other within the first heat conductive layer (20). The heat transfer liquid recirculation system (16) includes a first recirculation line (34) coupled between the collector and reservoir heat transfer tubes (30, 32) and has a recirculation pump (36). The temperature control system (10) includes a controller (40) operatively coupled to the first recirculation pump (36) so as to effect recirculation of water through the collector (12) and the reservoir (14) at predetermined temperature conditions. The phase change substance melts to store heat when the recirculation liquid temperature is high and releases heat by crystallisation when the recirculation liquid temperature is low.