What pressures do the high and low side run at on central air conditioners?

Question

I do car AC but never my house, does anyone know the high and low side pressures that a central air unit runs, at present its 75PSI on the suction side and 225PSI on the high side, its a 3 ton 10 seer.running r22

any answers would be welcome.

Chris

Answer 1

It is according to the tempature outside and your indoor heat load.

Normal Low side at 80 degree outdoor and 76 indoor would be about 72psi suction 225 head pressure.

If your head is higher than 250psi check you outdoor coil for dirt.

hope this helps

Answer 2

HVAC Tech.:  Your Pressures are those of a system in peak running condition. Temperature will effect them but not to much. As it warms up the head pressure will rise more rapidly than the suction side. A word of caution for what it is worth. It is ILLEGAL to access the refrigerant lines with out proper certification, BE CAREFUL!