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  1. #1
    Join Date
    Jun 2005
    Posts
    18
    My HVAC Contractor bent some fins on my brand new evaporator. He "pulled a vacuum" of 500 microns(?) and determined that there were no leaks in the system. I don't know for how long that reading held.

    If the bent fins leak, would this method detect the leak, or should a leak detector be used? It is a 3 Ton Puron system...

    Thanks!

  2. #2
    Join Date
    May 2004
    Posts
    12,285
    George

    Pulling a vacuum and watching a gauge for a certain amount of time is very common to determine if a system leaks but...there are rules he must follow to be sure.

    Bending fins should not cause a leak unless he penetrated a condenser tube. If he did, you would have heard it hissssss when he charged and ran it.



  3. #3
    Join Date
    Sep 2002
    Posts
    4,970
    not to worry about bent fins causing a leak. Now if something hit the evaporator real hard to bend them , thats another thing . Just straighten them out the best you can to not impead the air flow and dont worry about them.

  4. #4
    Join Date
    May 2004
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    12,285
    thanks "d"... thought I read condenser.

  5. #5
    Join Date
    Jun 2005
    Posts
    18
    Originally posted by dec
    not to worry about bent fins causing a leak. Now if something hit the evaporator real hard to bend them , thats another thing . Just straighten them out the best you can to not impead the air flow and dont worry about them.
    OK, so we're all agreed that the vacuum method would detect a leak? There's a small area of bent fins, and a little crease where the corner of the object must have smashed the fins.

    I want to MAKE SURE there is no leak.

    Tx,

    George

  6. #6
    Join Date
    Sep 2002
    Posts
    4,970
    Its not that uncommon to have a little frieght damage when this stuff is shipped. Im sure in your business your cliantel has to trust you......think you might have to put a little trust in who you hired unless this is one of those deals where you were not willing to pay the price for someone to do it right. May have got one of those lowball prices and now question how smart that was? If you were smart enough to hire a quality company they will stand behind their work. If nothing else just ask for something in writing saying they will stand behind it not losing any charge within the next 2-years.....if its leaking you will know by then. And no that does not cover it if you cause the leak in any way. Sure they would do that as compared to looking for something thats probably not there and just in the imagination of a paranoid customer.

  7. #7
    Join Date
    Jun 2005
    Posts
    18
    Paranoid... yeah, maybe. Forums like these will produce some of that reaction ... sort of like watching scary movies. Take a read of this site as a novice, and maybe you'll see why I think I can't be too careful.

    In my business, no offense, we just don't have forums like these, where professionals warn consumers about the wolves in the industry. I think the difference has something to do with what it takes to be in the industry. Not everyone can participate... it can take literally years to get a license, you need to have at least 5 years of college credits and you pass a 3 day test given only twice a year. On the other hand, consider Enron. A rather large betrayal of trust by those in my industry, and it had nothing to do with pricing. Just professionalism.

    What did Reagan say? "Trust, but verify."

    So again, I ask, if it can be detected this way, FOR SURE? If so, then fine. But I still have not heard the definitive YES, PERIOD, PARAGRAPH.

    Maybe I'm not listening well. Thanks for all your help, I do appreciate the feedback.



  8. #8
    Vacuuming to below 500 microns is not a test that insures a leak free system.
    (some will only leak under pressure)

    That said, it would take a pretty good hit to penetrate the copper tubing under the aluminum fins!

  9. #9
    Join Date
    May 2004
    Posts
    12,285
    Originally posted by lusker
    George

    Pulling a vacuum and watching a gauge for a certain amount of time is very common to determine if a system leaks but...there are rules he must follow to be sure.

    Bending fins should not cause a leak unless he penetrated a condenser tube. If he did, you would have heard it hissssss when he charged and ran it.



    The use of a CPA for the filing of your yearly income tax is very common to satisfy the IRS time requirements...there are rules he must follow to be sure (it is done properly).

    If it is done properly he should have been able to see if your system will leak. I can ask you 20 questions to varify the procedure but you would not know the answers. All we can say is "if it is done correctly, yes in most cases".

    Jules is also correct, there are some systems that will not leak under a vacuum but even Jules will tell you that is rare.

    Maybe this will help. If it leaks, you will soon know and he will have to come back to fix it under his warranty.




  10. #10
    Join Date
    Jun 2005
    Posts
    18
    I'm satisfied.

    Thanks guys, for all the comments and feedback.

    I do appreciate that you take the time and trouble...

    Tx,

    George

  11. #11
    Join Date
    Jan 2004
    Location
    PA
    Posts
    68,791
    I would hope on a PURON system he leak checked with nitrogen, since he used it when he brazed the line set.

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

  12. #12
    Join Date
    Sep 2001
    Location
    Vancouver Canada
    Posts
    996
    I would say that if he could pull it down to 500 microns in a reasonable time, that is a pretty good indication of no leaks in the system. Best to charge with nitro for leak testing but we usually pull to 500 and if it will hold for a reasonable time, we consider the system to be tight.
    "Go big or Go Home"

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