GB942688A - Improvements relating to space and water heating systems - Google Patents

Abstract

942,688. Heat pumps; refrigerating; hotwater supply systems; air conditioning. B. R. LEIGH. June 22, 1962 [June 22, 1961], No. 22639/61. Headings F4A, F4H and F4V. A heat pump includes first and second heat exchangers which respectively heat air for space heating and water for a hot-water system. As shown in Fig. 1, the first heat exchanger 3 is located in a duct 11 through which air is circulated by a fan 12 when space heating is required and the second heat exchanger 4 is located in an auxiliary water tank 14 which is connected to a hot-water storage tank 16 by flow and return lines 17, 15. A water circulating pump 18 is included in line 17 and the tank may be provided with supplementary heating means, e.g. an immersion heater, and baffles for reducing convection circulation therein. The evaporator 6 of the heat pump is utilized when space cooling is required and is defrosted by anti-freeze liquid dripped over it from a device 9. The defrosting is initiated and the heat pump compressor 2 stopped by switch means 8 in the suction line when the pressure therein rises above a predetermined value. Switches 20 on the high pressure side of the compressor have contacts in a control circuit (Fig. 4, not shown) which are arranged to control the water pump 18, the compressor 2 and a fan 29 in dependence on the refrigerant pressure at the compressor outlet and hence on the temperature of the water in tank 14. Thermostatic control of fan 12 is also provided. As shown in Fig. 2 the evaporator 6 is located in a duct 26 and the heat exchanger 3 in an aperture between a duct 38 and a chamber 36. When space heating is required the fan 12 draws filtered air from the interior of the building through an opening 37, chamber 36, exchanger 3 and a duct 41 which communicates with the exchanger 3 through an aperture 42, the heated air being supplied to the building through an outlet 13. The fan 29 is located in a duct 28 and blows air over the evaporator and through adjustable louvres 24 to atmosphere. When cooling is required flap valves 32 and 33 are raised (Fig. 3, not shown) separating ducts 26 and 28 and establishing communication between ducts 26 and 41 and between ducts 28 and 38. The aperture 42 in duct 41 is closed and the fan 12 now draws air from the exterior of the building through louvres 24, evaporator 6 and duct 41 while fan 29 blows air over heat exchanger 3 when the water in tank 14 is sufficiently hot to dissipate heat therefrom to atmosphere through a window 39. A window 31 in the duct 26 may be opened to allow air to be recirculated from the interior of the building to the evaporator.