Page 1 of 2 12 LastLast
Results 1 to 13 of 24
  1. #1

    New condensing unit-drier question

    I had a new condensing unit put in. Does the installer need to come out after a month and put in a new dryer? He says he put in a line dryer but not a suction dryer. Is that a problem?

  2. #2
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,755
    Made this its own thread.
    You are not permitted to post in other peoples threads in the AOP forums. Please read our site rules, thank you.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  3. #3
    Join Date
    May 2000
    Location
    Indianapolis, IN, USA
    Posts
    33,916
    Only if you put a new outdoor unit on a contaminated lines & coil. Then he should have put in a suction drier too.

  4. #4
    Join Date
    Jul 2004
    Location
    Massachusetts
    Posts
    6,829
    The purpose of a liquid line dryer is to collect minute bits of debris or to absorb small traces of moisture that could be now or in the future, in the system. Ideally the liquid line dryer is installed indoors near where it enters the air handler. A suction line dryer is installed in situations where larger amounts of contaminants are likely to be found. As Baldloonie stated, this is not the case unless the old compressor was a burn-out electrically. If it was, then a suction line dryer should be installed for a short period of time, then removed and/or changed as necessary. After the final removal, an acid neutralizer should be added to the system to prevent any remaining residue from starting a new round of contamination leading to a new burn out. It is my personal habit to install a single vial of acid neutralizer whenever I'm changing out a compressor or condenser, just for a little added insurance that some acid was present, though testing did not reveal it.
    If YOU want change, YOU have to first change.

    If you are waiting for the 'other guy' to change first, just remember, you're the 'other guy's' other guy. To continue to expect real change when you keep acting the same way as always, is folly. Won't happen. Real change will only happen when a majority of the people change the way they vote!

  5. #5
    This condensing unit was replaced because of multiple compressor failures with the old condensing unit. The coil has already been replaced. I'm afraid the whole system is somehow contaminated. Should I insist the installer come back out and put in a suction dryer,then come back out in a month and remove the dryer andadd acid neutralizer? Is there anything that can be done to asure the new(now two month old) condensing unit will not fail? Thanks

    it
    Quote Originally Posted by skippedover View Post
    The purpose of a liquid line dryer is to collect minute bits of debris or to absorb small traces of moisture that could be now or in the future, in the system. Ideally the liquid line dryer is installed indoors near where it enters the air handler. A suction line dryer is installed in situations where larger amounts of contaminants are likely to be found. As Baldloonie stated, this is not the case unless the old compressor was a burn-out electrically. If it was, then a suction line dryer should be installed for a short period of time, then removed and/or changed as necessary. After the final removal, an acid neutralizer should be added to the system to prevent any remaining residue from starting a new round of contamination leading to a new burn out. It is my personal habit to install a single vial of acid neutralizer whenever I'm changing out a compressor or condenser, just for a little added insurance that some acid was present, though testing did not reveal it.

  6. #6
    Join Date
    Aug 2007
    Location
    Northern VA 38 degrees N by 76 degrees W
    Posts
    5,058
    Quote Originally Posted by plea5ehelp View Post
    This condensing unit was replaced because of multiple compressor failures with the old condensing unit. The coil has already been replaced. I'm afraid the whole system is somehow contaminated. Should I insist the installer come back out and put in a suction dryer,then come back out in a month and remove the dryer andadd acid neutralizer? Is there anything that can be done to asure the new(now two month old) condensing unit will not fail? Thanks

    it
    The cause of the compressor failures should be determined through diagnostics. Compressors do not just die, something is causing the failures and by having multiple failures and nothing being changed but the compressor is a good indication that the new one will also fail.

    As for the drier, if it was a mechanical failure the liquid line dryer is fine, but if the compressor had an electrical failure, "burn out" then a suction line drier is required for clean up of the acid and must be removed after 72 hours of run time along with an acid test to see if system is clear of acid and if not procedure should be repeated.

  7. #7
    Replacing the entire condensing unit was supposed to solve the compressor problem, since a new condensing unit would not be contaminated. I am now wondering if the new condensing unit( and therefore the compressor) could become contaminated from the coil or lines.should I insist on the suction dryer/acid neutralizer or just trust that the installer did things correctly,even though the original system &/or installation 5years ago was obviously flawed?How should I proceed?thanks

  8. #8
    Join Date
    Apr 2004
    Location
    NJ
    Posts
    155
    If you experienced multple failures and they have all been electrical, an acid condition likely exists. At the very least, an acid test should have been performed in order to prevent condemning the replacement units to the same fate.

    The problem is that the oil, which travels throughout the system, becomes acidic when the compressor windings "burn out". The acid is a result of moisture in the system combined with high temperatures. When the condensing unit is replaced, some of the contaminated oil from the previous unit is still elsewhere in the system. When the new unit is started up, that contaminated oil is drawn back to the compressor, and the stage is set for motor insulation and winding breakdown (in other words, a new unit).

    Before the new condensing unit is installed, a procedure known as an acid clean up should be performed, along with installing a suction line drier (in addition to the liquid line drier). The suction drier may or may not remain in the system, depending upon how badly contaminated the oil was. I would probably remove yours, and perform another acid test. As Skip mentioned, neutralizer is a good idea as well.

  9. #9
    So what should be done now?The new condensing unit was put in 2months ago.Should the line dryer be replaced in addition to a suction drier installed?Then when should the suction drier be taken out?Should the acid neutralizer be added &/or an acid test? Is my new condensing unit now ruined? Thanks
    Quote Originally Posted by jaypslugger View Post
    If you experienced multple failures and they have all been electrical, an acid condition likely exists. At the very least, an acid test should have been performed in order to prevent condemning the replacement units to the same fate.

    The problem is that the oil, which travels throughout the system, becomes acidic when the compressor windings "burn out". The acid is a result of moisture in the system combined with high temperatures. When the condensing unit is replaced, some of the contaminated oil from the previous unit is still elsewhere in the system. When the new unit is started up, that contaminated oil is drawn back to the compressor, and the stage is set for motor insulation and winding breakdown (in other words, a new unit).

    Before the new condensing unit is installed, a procedure known as an acid clean up should be performed, along with installing a suction line drier (in addition to the liquid line drier). The suction drier may or may not remain in the system, depending upon how badly contaminated the oil was. I would probably remove yours, and perform another acid test. As Skip mentioned, neutralizer is a good idea as well.

  10. #10
    Join Date
    Aug 2007
    Location
    Northern VA 38 degrees N by 76 degrees W
    Posts
    5,058
    Quote Originally Posted by plea5ehelp View Post
    So what should be done now?The new condensing unit was put in 2months ago.Should the line dryer be replaced in addition to a suction drier installed?Then when should the suction drier be taken out?Should the acid neutralizer be added &/or an acid test? Is my new condensing unit now ruined? Thanks
    By installing a suction line filter dryer it will adsorb the acid and be removed from the system. The maximum time the suction line filter dryer should remain in the system is 72 hours of run time.

    By adding an acid neutralizer to a system in order for it to neutralize the acid a chemical reaction must take place and will ad other constituents to the refrigerant circuit. Not a good idea

  11. #11
    Join Date
    Jul 2009
    Location
    Columbia, MD
    Posts
    3,789
    a suction drier can stay in the system indefinitely. a pressure drop should be taken. if there is more then a 3psi difference, the dryer should be replaced.

    were the copper lines replaced? you said the evap coil was replaced? how well did they flush the lines.

  12. #12
    Join Date
    Aug 2007
    Location
    Northern VA 38 degrees N by 76 degrees W
    Posts
    5,058
    Quote Originally Posted by gravity View Post
    a suction drier can stay in the system indefinitely. a pressure drop should be taken. if there is more then a 3psi difference, the dryer should be replaced.

    were the copper lines replaced? you said the evap coil was replaced? how well did they flush the lines.
    What are you basing your statement on?

  13. #13
    Join Date
    Jul 2009
    Location
    Columbia, MD
    Posts
    3,789
    facts and experience.

    if a suction drier has no pressure difference across it then it can stay in the system.
    if the drier has a 3 or more psi difference then its time to replace the drier.
    the whole 72 hours is BS. a lot of techs dont know how to check them, so if manufacturers say no more then 72 hours then there may be a chance it might get replaced.

    we use a lot of core driers.

Page 1 of 2 12 LastLast

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