초록 ▼

An air-to-air heat pump with improved efficiency of operation, and simplicity and economy of construction. Initiation and termination of defrost cycles during heating mode operation is controlled, in addition to the conventional clock timer, by a dual pressure switch responsive to pressure in the ou

An air-to-air heat pump with improved efficiency of operation, and simplicity and economy of construction. Initiation and termination of defrost cycles during heating mode operation is controlled, in addition to the conventional clock timer, by a dual pressure switch responsive to pressure in the outdoor coil, thereby significantly reducing the length of defrost cycles with corresponding improvement in operating efficiency. The direction of refrigerant flow between the indoor and outdoor coils is established in a first line through the compressor by an electrically operated reversing valve, and alternatively through second and third lines, depending upon whether the system is operating in the heating or cooling mode, by series-connected check and float valves in each of such lines. When heating mode operation is resumed following a defrost cycle, the float valve has delivered all liquid-refrigerant to the indoor coil. Since there is no liquid refrigerant in the outdoor coil to be drawn into the compressor under these conditions, the usual trap type accumulator is not required and is therefore eliminated in the present system.

대표청구항 ▼

An air-to-air heat pump system comprising: (a) indoor and outdoor heat exchange coils respectively positioned inside and outside a space to which comfort heating and cooling is provided by said system; (b) a first line connecting said indoor and outdoor coils for flow of refrigerant therethrough in

An air-to-air heat pump system comprising: (a) indoor and outdoor heat exchange coils respectively positioned inside and outside a space to which comfort heating and cooling is provided by said system; (b) a first line connecting said indoor and outdoor coils for flow of refrigerant therethrough in first and second directions during heating and cooling, respectively, of said space; (c) a refrigerant compressor arranged in said first line; (d) a reversing valve arranged in said first line and movable between first and second positions to control the direction of flow of refrigerant therethrough; (e) a second line connecting said indoor and outdoor coils for flow of refrigerant from said indoor to said outdoor coil during heating of said space; (f) a third line connecting said indoor and outdoor coils for flow of refrigerant from said outdoor to said indoor coil during cooling of said space; (g) first and second check valves arranged in said second and third lines, respectively, to permit said flow of refrigerant therethrough in only one direction; (h) first and second float valves connected in series with said first and second check valves in said second and third lines, respectively, for controlling flow of refrigerant into said float valves; and (i) portions of said float valves relatively movable between open and closed positions in response to the level of liquid refrigerant therein for controlled flow of refrigerant out of said float valves.