R22 system service question

[Infohunter88]

Those pressures all depend on other conditions, indoor temp and outdoor temp,and filter condition, coil condition indoor and outdoor, fan speed and duct size and static pressure and and and and I could go on ............

[a/c-harris]

If you are fishing on here for some reason to get us to say that the tech did something wrong, it wont happen from me. It sounds like he followed proper procedures, and adding oil to a residential system is not something that is typically done. There is not a way to know how much to add. Its all throughout your entire system. Adding oil may oil slug your compressor and make the life even shorter. how long did the system run on the old leaking evaporator before it was replaced. If there is compressor damage it most likely occured before they even touched the system, you are just now seeing the side effects. I feel like you are trying to find something the company did wrong so you will get a free compressor.

[beenthere]

As said earlier.
Those pressures mean nothing with out knowing the conditions at the time they were taken.

[sarpanch2001]

If you are fishing on here for some reason to get us to say that the tech did something wrong, it wont happen from me. It sounds like he followed proper procedures, and adding oil to a residential system is not something that is typically done. There is not a way to know how much to add. Its all throughout your entire system. Adding oil may oil slug your compressor and make the life even shorter. how long did the system run on the old leaking evaporator before it was replaced. If there is compressor damage it most likely occured before they even touched the system, you are just now seeing the side effects. I feel like you are trying to find something the company did wrong so you will get a free compressor.

one more vote

[u2scsi]

No, there is no finger-pointing or blame. I do trust them; what started the whole discussion was when he told me R22 lubricated the compressor I felt I needed to check with others before signing off on the work.

I've been cleaning indoor and outdoor coils on my own since I bought the house new. The system is just over 5 years old, and the annual check by the A/C tech hasn't shown a problem until April of this year when he needed to add about a pound of R22. What they believe killed the evaporator was that the drain pan was angled down from the drain pipe, so that part of the coil sat in water the entire time (one side looked fine, the other was corroded. I also used a diluted bleach solution to keep the pipe clean, but since that also ran back to the pan, that helped speed up the corrosion.

Sounds like my concern about oil isn't valid, so I'm just trying to find other options before shelling out a few grand. Could the TXV introduce additional load? Could it have been charged higher than before; what would I observe if it was overcharged? Bottom line is if it's still cooling well is there anything I can do to help extend its operating life. If not, such is life. Thanks!

[emcoasthvacr]

for Houston, I would quess 70/210 if measured in the afternoon for this time of year -- 178 corresponds to an ambient of around 70 degrees with a condensor condensing 20-25 degrees above ambient -- normal conditions.

I don't know how much they put in, but I'm running 75 psi suction, and about 178 discharge. Is that too high?

[Shophound]

Crankcase heater won't do anything to prevent floodback of liquid refrigerant. A crankcase heater is to prevent a condition where when a compressor starts, liquid refrigerant that has settled into the compressor oil sump while the compressor was off suddenly flashes into a vapor when the compressor starts, and washes oil off critical lubricating parts, such as bearings, valves, etc.

A TXV does not impose an undue additional load on a compressor. If the compressor is a reciprocating model it should have a start capacitor and potential relay installed to help the compressor start against a closed TXV at startup. A scroll compressor may not need this addition for a TXV.

Without being able to analyze your system first hand there's no sure fire way to ascertain your compressor's health from here. Just going by your words I'd say the poor thing is in trouble and may be headed to compressor heaven in the near future. And there may not be much to head it off...a replacement is the only solution...and at five years you MIGHT be under warranty on the compressor, but you might not as well, should you be just outside of five years.

[u2scsi]

Hot start was added when they installed the TXV. There was a hot start previously installed by the contractor that installed the unit, but the capacitor had burned out (only rated for up to 3 ton units).

Guess it's time to start saving. Thanks for the advice guys!