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?