Patent GB-1061357-A (GB)
Title: Air conditioning system
IPC: F24F3/08
Filed: 1965-06-17
Abstract: 1,061,357. Heating and cooling buildings; heat pumps. TRANE CO. June 17, 1965 [March 29, 1965], No. 25682/65. Headings F4H and F4U. A system for heating and cooling buildings comprises heat exchange units fed by a hot water circuit 24, 26 containing a water heater 4 and a cold water circuit 32, 34 containing a water cooler 2, the pipes of the cold water circuit being of larger diameter than those of the hot water circuit and means being provided for utilizing the cold water circuit for hot water circulation during periods of high heat demand. As illustrated heat exchangers 10 and 12 are associated with the circuits in a four pipe system, water being admitted to the heat exchangers from the hot or cold circuit according to the setting of three-way valves 14, 16, 18, 20 as determined by room thermostats 84 and 86. The chiller 2 is the evaporator of a refrigeration circuit the condenser 41 of which may be cooled by a water flow through pipes 100, 102 or by return water from the hot circuit if such water has a temperature of below 95 F. as sensed at 114 when a pneumatic actuator 112 appropriately operates valves 104, 110. Water is normally moved round the hot circuit by a pump 28, a by-pass line having a pressure relief valve 44 being provided, and round the cold circuit by a pump 36, a by-pass line 50 and pressure relief valve 48 being provided. The changeover of the system to winter operation is effected, if a switch 136 is at " automatic " setting, by a pneumatic controller 132 responsive to external temperature sensed at 134, or, if the switch 136 is at " manual " setting, by a switch 76. The controller or switch cuts off air supply from a high pressure source 72 to the actuator 62 of a switch 66 of the hot water pump 28 and to the actuator 60 of a switch 64 of the refrigerant compressor 38 thus deenergizing these components. Valves 54, 56 and 58 are moved to their illustrated positions so that hot water is now moved by the cold water pump 36 through a circuit comprising a pipe 52 linking the hot and cold circuits, the heater 4, large diameter supply line 32, heat exchangers 10 and 12, a return line 34. The changeover to winter operation also moves a valve 80 to supply air at a different pressure to room thermostats 84 and 86 thus reversing their action. A controller 78 responsive to temperature sensed at 79 prevents changeover from winter to summer operation if the temperature of return water in pipe 34 is above 100 F. The temperature of water leaving the heater 4 is sensed at 118 and through an actuator 116 operates a steam valve to keep the temperature at 118 constant. The required constant temperature is set by a controller 128 according to external temperature as sensed at 129. In a modification, Fig. 1 (not shown), no provision is made for passing return hot water over the condenser, there is no heater temperature control, and the changeover from summer to winter operation and vice versa is solely manually controlled. In a further modification, Fig. 3 (not shown), each heat exchange unit comprises two heat exchangers, one in the hot water circuit and the other in the cold, passage through the exchangers being controlled by two-way valves.