Results 1 to 7 of 7

Hybrid View

  1. #1
    Join Date
    Jun 2005
    Location
    Colorado
    Posts
    34

    Pulling refrigerant into condensing unit

    The guys I work with have differing opinions on pulling the refrigerant back into the condensing unit for quick repairs. This is concerning only residential split units. Not heat pumps. 2 to 5 ton units. One question is about safety. If the system has a extra long line set can it be dangerous to pull all the refrigerant back into the condensing unit? Also, in general, my opinion is that it is best to recover the refrigerant. That way you know how much was in the system to start with plus it is better with these small units to simply use new clean refrigerant. Any feedback would be appreciated. Thanks.

  2. #2
    Join Date
    Mar 2009
    Location
    Mid-Mo
    Posts
    3,594
    If I don't suspect a charge problem, then I'll pump back what I can before the compressor internally bypasses then recover the rest.

    If I suspect there's something up with the charge then I take it all out. Especially if the factory installed drier is still in the condenser.

    Really for me is a case by case basis.

  3. #3
    Join Date
    Oct 2012
    Location
    Sacramento,ca
    Posts
    196
    Quote Originally Posted by ryan1088 View Post
    If I don't suspect a charge problem, then I'll pump back what I can before the compressor internally bypasses then recover the rest.

    If I suspect there's something up with the charge then I take it all out. Especially if the factory installed drier is still in the condenser.


    Really for me is a case by case basis.
    X2 i pump into the condenser until the low pressure switch cuts out then recover.

    One thing i have always heard is that it can damage the scroll tips once you get below 20psi. Is this true because i have gone on calls where scrolls have pulled a vacuum due to restrictions but after i correct the issue and recharge these compressors have still kicked for years.

  4. #4
    Join Date
    Aug 2010
    Location
    SouthEast Texas Gulf
    Posts
    15
    Newer scroll will go into bypass if condenser is full, older units you have to watch the amps and listen to the unit. Once unit is full close service valves and recover remaining line set. 95% of time a properly charged unit with a reasonable line set will pump into condenser without a problem. I've pumped hundreds of units into condenser to replace indoor coils, replace leaking driers and repair minor leaks in lines. If I have a large leak on a coil or line set I never pump the unit into condenser, just to avoid possibility of pulling non condensables into the system. If the system was so low that the suction side was pulling into vacuum with system running you should recover the system just to be safe.

  5. #5
    Join Date
    Mar 2009
    Location
    Mid-Mo
    Posts
    3,594
    Quote Originally Posted by Barrettservices View Post
    X2 i pump into the condenser until the low pressure switch cuts out then recover.

    One thing i have always heard is that it can damage the scroll tips once you get below 20psi. Is this true because i have gone on calls where scrolls have pulled a vacuum due to restrictions but after i correct the issue and recharge these compressors have still kicked for years.
    I've had pretty good luck with not doing damage under 20 psi for a short period of time. The couple that I know for a fact died from running in a vacuum, ran that way for an unknown amount of time.

  6. #6
    Join Date
    Oct 2012
    Location
    Sacramento,ca
    Posts
    196
    Quote Originally Posted by ryan1088 View Post
    I've had pretty good luck with not doing damage under 20 psi for a short period of time. The couple that I know for a fact died from running in a vacuum, ran that way for an unknown amount of time.
    Thanks. Thats kinda what i figured.

  7. #7
    Join Date
    Oct 2012
    Location
    Sacramento,ca
    Posts
    196
    Quote Originally Posted by ryan1088 View Post
    I've had pretty good luck with not doing damage under 20 psi for a short period of time. The couple that I know for a fact died from running in a vacuum, ran that way for an unknown amount of time.
    Thanks. Thats kinda what i figured.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event