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  1. #1
    Join Date
    Nov 2005
    Milwaukee, WI

    Moisture issue ( Puron units )

    So this thread is about how to solve my companies slight issue. When a issue occurs we take action and solve it no matter what it takes !!!!!!!!!!!!!

    Here is the deal :

    Our service tech's are telling us that they seem to believe there is moisture in some of the newer ( 05' - 06' ) systems that we have installed. They are NOT going back because of No-cools they are going back yearly for Tune Ups.

    They are saying there getting Flashing, the needle is ticking here and there

    So thats it..........

    Now we have to solve this problem, in order to do that I have to tell you how our procedures are.

    1. Always use Brand new linesets ( and filter dryers )
    2. Use the correct Puron solder
    3. Always purge the gauges before pressurizing the system.
    4. Pump with Nitrogen and purge from low side for 10 seconds ( My personal time, other installers may differ but I'm sure its the same )

    5. Pressurize around 150 to 250 PSI ( some guys go higher but I don't )
    6. Release Nitrogen till 0 psi
    7. Use a 6 cfm Vacuum Pump and run for 1hr. 30mins to 2hr.
    8. Release Refrigerant and setup and add or take out if needed.

    So after reading this I'm sure some will agree and some will not. These practices have been used for many many years. Then again sometimes being " OLD SCHOOL " becomes and issue.

    Another things is that I have been on this site for awhile, reading all the time and some of the things that are talked about ( Micron gage, double Evac and 6cfm vac pump possibly being to large ) I would mention because from going to school and learning about the THEORY !!!!!!!!!!! it makes sense on WHY to use them.

    I voiced my OPINION once or twice about ( Micron gage, double Evac and 6cfm vac pump possibly being to large ) and was told " na we have been doing this for years " <------------ I know %90 of the HVAC techs and installers hear this once a day/week hahahahahaha

    So a new guy like myself ( 1yr and 6 months) will just have to agree for the sake of not arguing. But NOW !!!! there seems to be a problem that the " New Guy " was already pecking on the boss about to prevent issues

    This is where being " OLD SCHOOL " may become and issue.

    Is R-22 tougher then 410a ?

    When I ask that I mean is it more or less sensitive to moisture or non-condensable ?

    I asked this because the ones that are having moisture problems are the 410a Puron units.

    Any help would be great.

    Hell I already mentioned to my Boss about our Vac Pump being to large and the possibility of moisture being froze instead of evacuated because it may be over sized. He looked at me and Hmmmmmmmmmmmm I see what you are saying.

    So whatever info I get from all of you can either make me look good or bad

    I believe there has been 2 systems that had some moisture issue. And that is after ALL our installs from the past years have been tuned up so it seems to be a very low occurrence. But the goal is to let this NEVER happen again.

    - Brad -
    I forgot my Pen !!!

    Quote Originally Posted by RoBoTeq View Post
    Think of the old stuff as dumb and strong and the new stuff as smart but just not so tough.

  2. #2
    Join Date
    Jan 2004
    Monday, I was doing a start up of a r410a system. Couldn't pull below 800 and could't hold below 1200 microns. Guages on manifolds didn't rise though.
    Finally discovered that the seal in my hose to the liquid line was cracked. Switched out the hose and was able to pull a vac to 250, and held 505.

    Without a vac guage on it, I never would have known that I wasn't pulling down the system. So that is the first correction youo should make to your procedures.

    How long are the line sets open to the atmosphere, that can effect the amount of moisture you have to remove during vac, and how much is left in system since your not using a micron guage to know if youo have the system pulled down.
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  3. #3
    Join Date
    Aug 2004
    North Richland Hills, Texas
    The more you use a micron gauge, the more you realize how critical it is to the process.
    If more government is the answer, then it's a really stupid question.

  4. #4
    Join Date
    Nov 2006
    We like to use a digital micron gauge along with removing the schrader valves. Use the good quality hoses and keep vacuuming until you can hold the vacuum to at least 750. Sometimes will take over 2hrs. until this level is achieved.

    I also try to change vacuum pump oil every day that I use it. Cost of doing business and this cost is calculated as is vacuum pump replacement.

    Check seals often as we have had cracked/split seals and o-rings and would not hold the vacuum.
    Avatar is a tribute to my Great Grandfather, Andrew Stewart. This pin was one of his advertisements for his heating and plumbing business. I never knew him but must of inherited his love of things mechanical since I am the only blue collar worker in the family

  5. #5
    Join Date
    Mar 2003
    Just to clarify one thing, it isn't the r-22 or r410 that holds the moisture it is the POE oil in the r410 systems as opposed to the mineral oil in r22 systems. If you aren't using a micron gauge you are only fooling yourself and cheating your customers.

  6. #6
    Join Date
    Aug 2002
    Office and warehouse in both Crystal River & New Port Richey ,FL
    Yes ,do it right,nitro,micron guage ,etc..

    However ,with what you are doing,coupled with a liquid line drier ,I'd think would handle the amount of moisture you may be leaving in.Just my opinion,time will tell.

    See my Puron left open to atomosphere,in the technical section.

    Exactly what moisture problems are you having???

  7. #7
    Join Date
    Apr 2007
    Just a thought and I may be wrong so if I am don't take my advice lol. Why not use a megger on the ones in question to get an idea if the refrigerant is breaking down faster than it should be. Without a vac gauge your pretty much guessing if your pulling a good vac. Smaller pump for longer run evac time. On the above post from dash one of the thread posters in there said he installed a crankcase heater while evac. to help release the moisture from the oil along with installing filter driers and last but not least filter drier replacement every time the system is opened.

  8. #8
    Join Date
    Nov 2005
    Milwaukee, WI
    Quote Originally Posted by dash View Post
    Exactly what moisture problems are you having???

    I will have to get back to you on this, I was just breifly told this yesterday and havent spoke to the Tech's yet.

    The boss already orders some nice Micron Gauges today
    I forgot my Pen !!!

    Quote Originally Posted by RoBoTeq View Post
    Think of the old stuff as dumb and strong and the new stuff as smart but just not so tough.

  9. #9
    Join Date
    Jul 2002
    Slacking off right now
    R22 is not "tougher" than the pink stuff

    its more forgiving of slack install practices the minerial oil is also easier to deal with.

    2. Use the correct Puron solder

    this mystifies me a bit what?

    anyway a micron gauge is a big help in knowing you have achieved a good vaccume

    always throw in a decent dryer in your install.

    410A req more exact install practices and has less room for error or short cuts - The best tool bags on the market - The offical tool bag of choice by techs everywhere

    Arguing with some people is like wrestling a pig - eventually you realise the pig actually enjoys it

    Gonads serve a useful purpose but are no substitute for brains

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