Heating Help

It's called superheat

@ December 5, 2010 10:34 PM in Ice build up

The aged/missing insulation is the culprit but not necessarily the villain... More than likely all is okay with the exception of increased superheat in the refrigerant system during the summer months which decreases efficiency... An iced up suction tube can indicate floodback of liquid refrigerant of which we all know one cannot compress liquid; or to clarify, a compressor cannot compress liquid... But with a freezer, a suction tube can simply be extremely cold with zero return of liquid refrigerant and moisture in the air surrounding the piping freezes to the exposed tube and over time builds up ice like your pics show... If this system has run this way for years then I'm guessing an insulation remodel is in order and leave it at that... To be positive you could have a refer dude check the superheat on the system to insure there's no floodback of liquid refrigerant which will eventually cause compressor failure... Or to educate yourself, locate the instructions that come with a thermostatic expansion valve (like Emerson) and you'll get an idea of how to measure superheat...  cheers,  kooler

now that you mention it

@ September 15, 2010 3:03 AM in TXV's

I did have a system that (I think) eventually did the compressor in... Walk in Freezer - R404a - that as about 4 years went by from the original install gradually starved the coil.. I'm in a small town that's small enough that I'm the only guy that works on this stuff and this TXV eventually starved the coil enough that no adjustment worked at all... And there was no corrosion on the power head to indicate loss of charge but I concluded at that point in time that was the problem... BUT then I replaced the valve with a like-size 502 that was not externally equalized but internal (plugged the coil equalizer line) only because that was what I had on hand (weekend, only thing on hand, you know how it is) and the immediate response was perfect... Fed beautifully and thought problem solved.. Within 6 months the same problem returned, no adjustment would change anything and the coil was starving, big ice block around the TXV and that entire end of the evap... Only this time compressor operation was affected... Even with a third TXV replacement (back to external equalized) head pressure was too extreme with the original full charge of refrigerant... Looking at internal TXV parts revealed nothing unusual other than the typical stickiness feel of an R404 system I've grown accustomed to.. I'm of the opinion that filter drier replacements are to become common place on an annual basis with the HFC system instead of just one that needs servicing when a system is accessed... Eventually I replaced the compressor on this system to once again attain satisfactory running pressures and a normal sight glass... Time will tell how the 3rd TXV will endure normal operation...   Great post, cheers   -    kooler

@ February 6, 2003 4:36 PM in Just wondering, where we all from?

delta jctn/ft greely, alaska