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[Welder]

A novice!

Can anyone advise what temperature i should expect on an R22 a/c System after the condenser (expansion device is in the outdoor unit).i pressume at 250psig it shoul be 45 deg c

[sedgy]

hi welder,
on my compariter 250psig=47c
the psig after the ex , valve which is now part of the evaporator< thats why its got armaflex on it< can drop to 58psig but most a-c units run a little higher, up to 70 psig.
the reason for having the ex, valve in the condencing unit is to save on the ammount af gas in a system,
hope this clears up your question,
sedgy,

[Welder]

hi welder,
on my compariter 250psig=47c
the psig after the ex , valve which is now part of the evaporator< thats why its got armaflex on it< can drop to 58psig but most a-c units run a little higher, up to 70 psig.
the reason for having the ex, valve in the condencing unit is to save on the ammount af gas in a system,
hope this clears up your question,
sedgy,
Thanks sedgy.perhaps you could assist with another one? checking the temps on the liquid and suction i get 5 Deg (70psig) liquid 13 deg suction (92psig) so +7 accross the evap.Does that sound correct for R22 and what would you expect for 407 and 410a?

[sedgy]

hi welder,
I retiered years ago so I would not comment on this new stuff, but when setting up your system , you can normally trim your suction temp by first weighing in the refrigerant, and if you are lucky you can adjust the con,d fan to give a ideal temp to the liquid < the higher the liquid temp , the higher the suction temp < to a limit of couse

[Peter_1]

...
the reason for having the ex, valve in the condencing unit is to save on the ammount af gas in a system,
hope this clears up your question,
sedgy,

The main reason is avoiding the sissing/hissing noise in the indoor unit. The amount of gas doesn't reduce that much because you still have mainly liquid in the LP liquid line towards the indoor unit.

[Peter_1]

hi welder,
...and if you are lucky you can adjust the con,d fan to give a ideal temp to the liquid < the higher the liquid temp , the higher the suction temp < to a limit of couse

Sorry Sedgy, with all my respect but I disagree also a little bit on this one: this is not the case with all the nowadays inverter driven AC systems. They decrease speed when LP drops and HP increases too much.

@Welder..ambient temperature?

[sedgy]

peter, thank you for your views about inverters, I did not know that, I have never worked on one, welder never told me it was an inverter, and with it being on R22 I doubt it. as I said in my thread , I have been retired a few years now, and I did say if you are lucky you can adjust the con,d fan to trim the temp,
regards sedgy

[Welder]

Sorry Sedgy, with all my respect but I disagree also a little bit on this one: this is not the case with all the nowadays inverter driven AC systems. They decrease speed when LP drops and HP increases too much.

@Welder..ambient temperature?
Oh Ambient is 12 deg c

[nike123]

Thanks sedgy.perhaps you could assist with another one? checking the temps on the liquid and suction i get 5 Deg (70psig) liquid 13 deg suction (92psig) so +7 accross the evap.Does that sound correct for R22 and what would you expect for 407 and 410a?

If you are talking about split system, than in cooling mode, both lines are part of evaporator and what you see as 5°C is line with flash gas between expansion device and indoor unit heat exchanger (that mean saturation temperature) and 13°C is line between heat exchanger and 4 way valve in indoor unit which mean that temperature represent superheated vapour. 13°C-5°C = 8K superheat.
Is it correct or not, depend on superheat table given by equipment manufacturer and value depend on indoor air wet bulb temperature and outdoor air dry bulb temperature and correct air amount.