A liittle help...
This should probably be in the commercial section, but not much activity there.
Normally I just do commercial refrigeration, but was called out by a well driller I know, who does ground source heat pump installations.
The job was at a fabrication shop, new build (10-14), with 2, 5 ton heat pumps (well source), supplying heated water to an in-floor loop.
The problem was units were tripping out, on occasion, on low evap temperature on the suction side. The installing contractor went through all the usually problems, water flow, bad thermister, etc. All good.
I went out, checked pressures, (BTW 410A) and had a 280# head and 45# suction. 70 deg superheat. According to the operating charts, head is right on, but suction is way low, and superheat is crazy high. I said it might be low charge or bad/restricted TXV.
The installer has been going round and round with the manufacturer, they made another call to the manufacturer while I was there, and this time they said that the s/n of the units showed that they had Copeland scrolls that had the parts cleaned by an improper solvent during construction, and precipitated out a particulate matter that restricted the reversing valve and TXV.
Their resolve to the problem is to add CalgonRe-New to the system, switch back and forth between heating and cooling, and this magic product will "dissolve the blockage", and be removed with a refrigerant recovery.
I call BS on this, but would appreciate other opinions. Thank you.
Experience is what you have an hour after you need it.
Sorry, no BS on this one. I don't have all the particulars but a rust inhibitor reacts with the oil and refrigerant and creates a black sludge that keeps the TXV from moving. If you do a search there is a whole tread on it here.
I have not heard much about this lately, is that the way copeland is going to fix this mess.?
why not just add IceCold.... it'll supossedly do the same thing....
Originally Posted by baub
Experience - knowing when to get the hell out of the way and plug your ears. "Don't be a sissy. Turn it on!"
Poodle Head Mikey - "the world is well populated with the unknowing and the uncaring and the stupid."
Originally Posted by HVAC_Marc
I wonder if green means it turns into a gooey green sludge inside the system