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  1. #1
    Join Date
    Aug 2012
    Posts
    9

    Replace Filter-Dryer or add another?

    I’ve got a new R22 2-ton split system that was recently installed by another tech. That tech flushed out the lines with compressed air (apparently to “clean” the lines). This appears to have introduced a lot of water into the system. When I got to it the system was not cooling at all with the high side pressure at 350 PSI and the low at 25 PSI. When more freon was added the suction line temperature went up not down. It seems obvious to me that the flow is obstructed by ice on the orifice and that the system needs to be evacuated and vacuumed to remove the water.

    Now my question is: do I need to replace the filter-dryer or can I just add another? The existing filter-dryer is in the condenser and seems hard to replace.

  2. #2
    Join Date
    Jul 2011
    Location
    East coast USA
    Posts
    1,002
    i would replace and not add.

  3. #3
    Join Date
    Mar 2005
    Location
    burlington county n.j.
    Posts
    9,765
    cut out the drier and replace with copper, install new drier in liquid line after the service valve.

  4. #4
    Join Date
    Mar 2009
    Location
    Mid-Mo
    Posts
    3,596
    Quote Originally Posted by t527ed View Post
    cut out the drier and replace with copper, install new drier in liquid line after the service valve.
    This is always a fun task but gets my vote.

  5. #5
    Join Date
    Aug 2012
    Location
    Palmyra, Missouri, United States
    Posts
    224
    never install a second liquid drier. always cut and remove.

  6. #6
    Join Date
    Sep 2003
    Posts
    1,677
    Just for Giggles isn't it Illegal to install a new R-22 split system?

    Anyway I would take apart that system at the piston and remove it.

    i would replace that filter drier and evacuate.

    Then I would send dry nitrogen through it let it sit and evacuate again

    Evacuate again and try holding at 300 microns and see if the gauge holds or it migrates upwards

    Might have to use Nitrogen a couple of times to dry it out.

    But yes, change that filter drier And remember to reinstall that piston

  7. #7
    Join Date
    Mar 2002
    Location
    fort walton beach fl.
    Posts
    790
    Quote Originally Posted by ryan1088 View Post
    This is always a fun task but gets my vote.
    Agree. I would also add a suction line dryer as well.
    http://acfwb.com/

    "The best preparation for good work tomorrow is to do good work today"

  8. #8
    Join Date
    Jun 2001
    Location
    Moore, Oklahoma, United States
    Posts
    4,514
    Quote Originally Posted by small change View Post
    Just for Giggles isn't it Illegal to install a new R-22 split system?

    Anyway I would take apart that system at the piston and remove it.

    i would replace that filter drier and evacuate.

    Then I would send dry nitrogen through it let it sit and evacuate again

    Evacuate again and try holding at 300 microns and see if the gauge holds or it migrates upwards

    Might have to use Nitrogen a couple of times to dry it out.

    But yes, change that filter drier And remember to reinstall that piston
    Tons of "dry" R22 units are installed all the time. Sales of dry R22 units exceed that of R410a units in some areas.

  9. #9
    Join Date
    Aug 2012
    Location
    Tennessee
    Posts
    67
    Compressed air is a no no. All air has moisture in it. I would recover R-22, blow nitro through it to get any debris out, flush my line set, replace liquid drier, nitro test for leaks, pull vacuum, charge with virgin R-22

  10. #10
    Join Date
    Dec 2011
    Location
    North Texas
    Posts
    668
    definitely yank the drier. you leave it you're gonna have to go back and remove it later. flush her out with the nitrogen and pull a good LONG vaccum

  11. #11
    Join Date
    Sep 2012
    Location
    New York
    Posts
    175
    I would definitely cut out the old drier and replace with a new one. If you add a second drier and keep the original one you could create pressure drop in the system. The old drier is most propably absorbed any moisture in teh system already so why risk it. I agree add a suction line drier as well!

  12. #12
    Quote Originally Posted by RJ777 View Post
    I’ve got a new R22 2-ton split system that was recently installed by another tech. That tech flushed out the lines with compressed air (apparently to “clean” the lines). This appears to have introduced a lot of water into the system. When I got to it the system was not cooling at all with the high side pressure at 350 PSI and the low at 25 PSI. When more freon was added the suction line temperature went up not down. It seems obvious to me that the flow is obstructed by ice on the orifice and that the system needs to be evacuated and vacuumed to remove the water.

    Now my question is: do I need to replace the filter-dryer or can I just add another? The existing filter-dryer is in the condenser and seems hard to replace.

    "Never pressurize a system with oxygen or compressed air because dangerous pressures can be generated from a reaction with the oil as it oxidizes."

    In other words, scary things can happen...

  13. #13
    Join Date
    Nov 2004
    Location
    Austin, TX
    Posts
    888
    Like some of the others said.

    Replace old with a piece of copper tubing and install new one outside. I'd also install a moisture indicator sight glass to tell when the system was dry. I'd flush it with dry nitrogen and do a triple evac breaking the vacuum with nitro twice. Do final evac to 500 microns. The moisture indicator will indicate when the system is dry. A badly contaminated system can take longer than you think. The moisture indicator keeps you from guessing.
    “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

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