A lot of times when I am checking TXV equipped units I’ll have normal pressures with a very low subcool. For example. 75 indoor. 20 delta t. 85 outdoor. Pressures around 320/130 psi. Subcooling 2. What would cause this? Now I know low subcool could be indicative of a low charge but with these pressures and good delta t I don’t think this is the case. I guess the superheat would come into play here as well to determine why the subcool is so low?
“Normal” pressures, low subcool
Ghyde6005
101 - 120 of 166 Posts
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OP, you say an awful lot of "seen it many times" & " got 100's just like that" & "they can't ALL be wrong". How about some book knowledge mixed up in there somewhere.? Got milk? Got info?Then w/ some solid references we might start to listen to you and you might even help educate us. But Dude, not the "I SAW IT. I SWEAR!" way. Not with "this crowd"! We need proof, not jaw flapping.
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He's not a Tech
He's a PM Grunt. I wonder if he works for one of those...……...He's breathing, He's qualified, Give him a truck and make us Money!
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So your saying with a 70° indoor temp and 75° outdoor temp the suction pressure will go up as the outdoor temp goes up?
ayattention:
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I’ve seen r22 at about 40 psi when it’s 50 f outside
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and the coil isn't freezing?
Without knowing head pressure that's a useless fact. It's obviously wrong, it won't work right.
R22, at 40 PSI is 18*F saturation temp which would freeze your evap coil inside, so what did you do about it?
Lol i don’t have to prove shit to you. I still can’t believe you don’t think suction pressure is correlated with outside dry bulb temp. Did you retire when they were still using r12 or something?
Suction pressure will change slightly depending on exterior conditions or wherever your condenser is but the simple fact is that the system is designed to work within a wide range of ambient temperatures. It's not like your A/C won't work in the winter just because it's cold. There's components and features added to make up for such things.
IF your suction pressure is way too low, I don't care what temp it is outside, there's a problem that needs to be fixed.
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The more you open your un-professional mouth the more stupid you sound. YOU CAN'T PROVE CRAP, CAUSE YOU ARE NOT QUALIFIED. that is obvious. Sure sounds like you did go at least one school, "The WAY OF HVACR & SNOTTINESS" by The GURU.
Why do you not have to prove to us what you claim?? WHY?
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I must have gone to a different school for Thermodynamics then you did!
How does a Water Cooled (GEO) system operate with 55°condenser water?
Suction pressure is dependent on Temperature across the evaporator. At 50°f ambient you'd better have some type of head pressure controls!
There’s a reason why most user manuals tell you not to operate your AC when it’s below 55 outside. I’ve had to do plenty of checks were it was only 40 outside. I’ve seen suction as low as 30 psi and was fine that summer without putting refrigerant in
Well that’s why when we re told to do pms in that cold of weather we can only run them for a few minutes. We can use the bag over the condenser trick but only on txv units
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Yes there is a reason...……………………..
Why is that?
We run A/C & Refrigeration systems in all temperature and conditions!
Because I know what I see in the field and what is normal and what is not. But then again all these hundred of units are all mismatched and undersized right. What do I have to gain by proving anything to you? Street cred in a forum? I must be doing something right if they put me on call and have had me doing PMs for years. Or maybe my company and clients are so desperate that they’ll take anybody right
I agree
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Tell me how we can do that? Wiseguy / GURU
Of course it is that’s why we only can run them for a few minutes when we check them. I don’t agree with this practice but I don’t schedule the checks
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