摘要 |
An apparatus for controlling the temperature of one or more enclosed spaces is described. It comprises a heater (42), a heat exchanger (32), an air path which connects a suction passage (14) and a discharge passage (16) and contains an air circulation means (34). The suction and discharge passages (14, 16) are connected to each enclosed space by vents, which are selectively operable in response to the temperature in the space to allow passage of air therethrough. The system can operate in two modes, one, when cool air is required, in which the air path includes the heat exchanger alone and a second, when a change to hot air is required, where it includes the heater. In the second mode, in one embodiment, the air path passes over the heater alone so that hot air is immediately available, while, in a second embodiment, the air passes over both the heater and heat exchanger so that hot air passes through the heat exchanger to raise its temperature. The advantage of the arrangement is that the apparatus can be rapidly switched from cooling to heating allowing efficient and accurate temperature control. |