It might seem pretty simple to test a subcooler, but leave it to me.
Was looking at one yesterday and trying to test or prove performance. Mostly for my own satisfaction, but also am looking to make this a part of annual testing.
Inlet liquid temp was 66 degrees.
Running full subcooling which was a 5 ton valve, I think, at a 40 degree evaporator temp. I measured 2-5 degrees superheat on the subcooler.
Outlet temp was 67 degrees?
Something doesn't add up here. What am I missing?
these reading do not make sense :)
First checks are to make sure your subcooling circuit has a solid column of liquid feeding the TEV.
Then make sure your liquid to be subcooled is a solid column.
key point here being (you cannot subcool vapor)
Then your subcooling circuit should have around 10 to 12* superheat (40*SST with a 50* sensible suction pipe temperature)
Your liquid to be subcooled is entering at 66* and should be leaving towards the liquid header at around 50 to 55* sensible pipe temperature.
The readings you provide give me the impression that your subcoolers TEV is leaking through the push rods and into the externally equalized line. Giving you a low superheat reading, with no active heat transfer on your liquid to be subcooled.
Didn't make any sense to me, either, that is why I brought it here.
Originally Posted by Phase Loss
Solid column of liquid for both.
Didn't think about that happening with the TXV. :o
Seen it happen a few times.
If you change the TEV, consider Sporlans Y1155. it is designed for subcooler operation.
I knew there was a subcooler TEV out there.
It is a wide range valve, right? That would require repiping to do away with the dual valve arrangement. Might not be a bad thing.
Who else would make a specialized supermarket flow control valve. :D
Originally Posted by jpsmith1cm
Sounds like you need to set the valve. Why would you remove the duel valve set up? the Y series works well in this application.