Question

with a yourk air condition freon 22 what is the normal preasure of the gas retreturning to the compressor??

Answer 1

Standard design conditions for an R-22 air conditioning system calls for the suction pressure to the compressor to be 68.5 psi when the return air is 75 degrees F. As the return air temperature changes, the suction pressure will change. Lower temperature will produce lower suction pressure, higher temperature will produce higher pressure. 68.5 psi for R-22 corresponds to a 40 degree F boiling point. The normal boiling point with an R-22 system and a standard efficiency evaporator coil is 35 degrees below the return air temperature. That is assuming that there is a correct flow of air across the evaporator coil. If the filter is dirty, less air will be blown across the evaporator coil and less heat will be available for transfer into the refrigerant. That will result in a lower suction pressure and boiling point. Any restriction in the air flow path will do the same thing. There should be 400 cubic feet per minute of air flow for each 12,000 btu's of capacity. 12,000 btu's equals 1 ton of refrigeration capacity. There can be several reasons why air flow can be restricted, dirty filters, sticking or binding bearings on the blower motor, debris in the blower's squirrel cage, a bad run capacitor, incorrect speed winding selection, blocked vents, a blocked return, etc.