Originally posted by pliscon The little overflow or balancing line on the Txv is what I am talking about being brazed.
That "balancing line" on a TXV is actually called an equalizing line. It is so the power head on the TXV will read the pressure of the evaporator at the evap outlet vs. what the pressure would be if the power head used the pressure at the evap inlet. This accounts for pressure drop through the evap coil and also allows the pressure being exerted on the power head to correspond with the superheat at the evap outlet.
By all means braze this line into place using material you're most comfy with. Better yet, use a tee with the proper size fittings. Sure beats punching or drilling a hole in the suction line, hoping to God any debris doesn't enter the system, and then hoping to God even more you don't burn the equalizer line in two when you braze it up. Oh yeah, and flow nitrogen when you braze.
Sorry about prodiyer going south on you. I kinda suspected with a handle like "prodiyer" and from his posts said we weren't dealing with a seasoned pro.
Also, I think the other guys are trying to say that if you're getting a lower suction line temp at the compressor than at the evap, you might have a suction line restriction. Rare, but it can happen. I would double check how I take the readings and ensure there's not something you're overlooking. If you're just two degrees off with the suction line being the one that is warmer, we're back to an overcharge situation.
Electricity makes refrigeration happen.
Refrigeration makes the HVAC psychrometric process happen.
HVAC pyschrometrics is what makes indoor human comfort happen...IF the ducts AND the building envelope cooperate.
A building is NOT beautiful unless it is also comfortable.
Originally posted by prodiyer I know carrier on their high efficency units have required subcooling right on the nameplate at the outdoor unit. How do you determine what the required subcooling should be?
First you come here and try to act like a professional...
And now, you are asking basic refrigeration questions!
Are you adding freon for the lineset length over 15' plus freon for the evaporator coil? Doesn't the condenser come precharged for 15' of lineset and the coil?. In other words if you just had exactly 15' of lineset, you would not need to add any freon. That is the way I was taught.
First of all jultz, you said required subcooling is never found on the nameplate and you are wrong! I asked how do you determine what the required subcooling should be? If this is basic then you shouldnt have a problem answering it.