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  1. #1
    Join Date
    May 2007
    Location
    Houston, TX
    Posts
    9

    R22 system service question

    Goodman 4-ton condensing unit, Goodman 5-ton evaporator.

    My 5 year old evaporator was replaced earlier this week (don't use clorox), and they had to evacuate the entire system because the service valve on the high-side line was stripped out. After the evaporator was installed, they removed both line driers (one was installed inside the condenser by the mfgr) and replaced them with only one. A vacuum was drawn, and then the system was recharged with R22. I have limited experience with automotive A/C systems, but shouldn't some oil have been added if the entire system was evacuated? I asked the A/C tech that question and he said that the R-22 acts as a lubricant when it becomes a liquid, but that doesn't make sense. All I know is that they had a large green canister of R-22; I don't know if that has any mixed in or not. Thanks.

  2. #2
    Join Date
    Nov 2004
    Location
    Austin, TX
    Posts
    873
    A miniscule amount of oil comes out when evacuating the system.
    Most of the oil is in the compressor. It's not a problem on residential systems.
    I am for doing good to the poor, but...I think the best way of doing good to the poor, is not making them easy in poverty, but leading or driving them out of it. I observed...that the more public provisions were made for the poor, the less they provided for themselves, and of course became poorer. And, on the contrary, the less was done for them, the more they did for themselves, and became richer.
    ― Benjamin Franklin

  3. #3
    Join Date
    Aug 2002
    Location
    Southern NJ
    Posts
    962
    If charged properly you should not have a problem.

  4. #4
    Join Date
    Jan 2007
    Location
    Western Suburbs of Philly
    Posts
    430
    removing both the factory installed drier and the external drier and replacing with a single new one is a good service practice that many do not take the time to do. Re-charging the oil on a hermetic resi system is rarely, almost never, needed. Sounds like your guy is at least in the upper 50% of the resi techs out there.

  5. #5
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,875
    Except for telling you the liquid r22 will lubricate the compressor, it sounds like you got a good tech.

    4 ozs or less oil came out when they recovered your system. Nothing to worry about.
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  6. #6
    Join Date
    Dec 2006
    Location
    New Jersey
    Posts
    747
    there is no oil in virgin 22.

  7. #7
    Join Date
    Mar 2007
    Location
    A Lan Far, Far Away in Podunk, Georgia
    Posts
    234
    The oil is distributed throughout the system when it is running.
    Some oil is in the compressor, some in the condensor, evaporator, line set and driers.
    There is no way to determine exactly how much oil is where when changing out an individual component.

    Very little oil, if any, will be removed by the evacuation process. Vacumm pumps won't pull down to reach the vapor point of oil so it mostly stays put.

    The entire system would have to be flushed to remove all the existing oil before the correct amount of oil could be added back in.
    Otherwise adding oil would be just a 'guess' as to the amount to add.
    The benefit is just not worth the effort in this case.

    Some techs will choose an arbitrary amount depending on the component replaced but it is really an educated guess.

    I like all the previous answers too.
    Sounds like you're in good shape!

  8. #8
    Join Date
    Aug 2003
    Location
    Fort Worth, TX
    Posts
    11,316
    Other than the tech not explaining how oil circulates inside a refrigeration system very well, sounds to me like he did good. I remember the days of purge n' gas it up...evacuate??? I now know better. EPA rules also changed things...in that respect, thankfully.
    • Electricity makes refrigeration happen.
    • Refrigeration makes the HVAC psychrometric process happen.
    • HVAC pyschrometrics is what makes indoor human comfort happen...IF the ducts AND the building envelope cooperate.


    A building is NOT beautiful unless it is also comfortable.

  9. #9
    Join Date
    May 2007
    Location
    Houston, TX
    Posts
    9

    R22 system service question

    Guys,

    Over the last few months, my compressor has gradually gotten louder, and now I'm noticing a metallic grinding noise for the first few minutes when it first kicks on. Prior to the service, it was quieter. Aside from the evaporator and the drier replacements, I had them install an expansion valve which he said would pose an additional load on the compressor (hot start also added), but will provide me with cooler air. I have noticed that despite my decreased running time, my electric load during the summer had increased. I am concerned that the louder noise during operation and the metallic noise when it first starts up is an indication that it is not getting properly lubricated. If this is the case, can oil charges be added much like automotive systems or is it an indication of permanent damage?

    If oil is not the issue, what else can explain the louder noise or the grinding?

  10. #10
    Join Date
    May 2007
    Location
    Houston, TX
    Posts
    9

    R22 system service question

    Guys,

    Over the last few months, my compressor has gradually gotten louder, and now I'm noticing a metallic grinding noise for the first few minutes when it first kicks on. Prior to the service, it was quieter. Aside from the evaporator and the drier replacements, I had them install an expansion valve which he said would pose an additional load on the compressor (hot start also added), but will provide me with cooler air. I have noticed that despite my decreased running time, my electric load during the summer had increased. I am concerned that the louder noise during operation and the metallic noise when it first starts up is an indication that it is not getting properly lubricated. If this is the case, can oil charges be added much like automotive systems or is it an indication of permanent damage?

    If oil is not the issue, what else can explain the louder running noise or the grinding?

  11. #11
    Join Date
    May 2007
    Location
    Houston, TX
    Posts
    9

    R22 system service question

    Well, the tech came out and said the noise is an indication of an internal problem. It's also pulling about 6 amps more than what is stamped on the housing. He's going to look into an oil charge and talk with his peers; he also suggested that a crankcase heater MAY help extend the life if the issue is the returned R22 still liquid.

    Suggestions?

  12. #12
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,875
    If the refrigerant is returning to the compressor as liquid. They should fine the cause. Its not suppose to be liquid when it gets to the compressor.

    They might have it over charged.
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  13. #13
    Join Date
    May 2007
    Location
    Houston, TX
    Posts
    9

    R22 system service question

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

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