Head and suction pressure relationships

[Swinder]

I understand that high head pressure will raise your suction pressure, and that high suction will raise your head pressure. But I was wondering if this is solely based on the compressors compression ratio or if their is something else involved.

[valdelocc]

I understand that high head pressure will raise your suction pressure, and that high suction will raise your head pressure. But I was wondering if this is solely based on the compressors compression ratio or if their is something else involved.

Heat gain and heat loss are the main factors, gain too many btu's in the evaporator; suction goes up, cant get rid of enough btu's in the condenser; well they stay for another ride and head goes up, all the compressor is doing is moving the merry go round, when too many riders (btu's) get in and not enough get out, well there is trouble.

[Swinder]

That makes perfect sense, thanks a lot!

[Tommy knocker]

Heat gain and heat loss are the main factors, gain too many btu's in the evaporator; suction goes up, cant get rid of enough btu's in the condenser; well they stay for another ride and head goes up, all the compressor is doing is moving the merry go round, when too many riders (btu's) get in and not enough get out, well there is trouble.

Excellent!!!

[passintyme]

Good analogy Val.. The science behind it is Dalton's law... And your p.t. Chart... Raise the pressure you raise the temp and lower the pressure you lower the temp... So if it compression and load related the law stands because you are increasing work being done... If it is false load such as dirty condenser you raise the pressure which will......increase the pressure. Conversely in a evaporator if you plug it up you lower the temp which lowers your pressure because there is less work being done (heat transfer).... Hope it helps.