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  1. #1
    Join Date
    Aug 2007
    Location
    Atlanta
    Posts
    2

    Loss of Freon When Checking Subcooling Superheat ??

    When a technician is testing the charge level or subcooling or superheat, and is using gauges with hoses that are several feet long, how much Freon is lost from filling up the hoses? Should the technician have a canister of Freon with him to replace what is lost when he completes his system check? Thanks.

  2. #2
    Join Date
    Aug 2004
    Location
    Kentucky, Michigan, Ohio, Arizona, Colorado, Nevada, and Califormia
    Posts
    318
    If the hoses have low loss fittings like most of ours do, the loss is minimal and would take several thousand "checks" before affecting performance.
    "Surprised ?! If I woke up tomorrow with my head sewn to the carpet, I wouldn't be more surprised."
    Clark Griswold

  3. #3
    Join Date
    Jul 2001
    Location
    VA
    Posts
    2,801

    Fair question

    With low loss fittings and proper techniques you won't lose enough to make a difference with regular service. Should they put more in just because they hooked up? No. The amount you are talking about is not readily measurable, so all they would do is screw the charge up.
    ___________________________________________


  4. #4
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    68,114
    Should he have a jug of gas in the truck yes.

    Should he try to put .25 oz. back in, no. ( presuming low lose fittings )
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  5. #5
    Join Date
    Nov 2005
    Posts
    1,350
    Be careful, many of the techs on this site and many in the field use one set of gauges for all residential refrigerant types. Which means they dump the charges on their gauges after each use. If your system is near critical and the tech has 6 foot hoses it could affect system performance.
    I STARTED WITH NOTHING, AND I STILL HAVE MOST OF IT!

  6. #6
    Join Date
    May 2004
    Posts
    12,028
    Quote Originally Posted by emoney1971 View Post
    Be careful, many of the techs on this site and many in the field use one set of gauges for all residential refrigerant types. Which means they dump the charges on their gauges after each use. If your system is near critical and the tech has 6 foot hoses it could affect system performance.

    (cough)

    Bull****

    Please explain to this group what you mean by "critical charge" on a residential unit and how loosing less than on ounce of refrigerant will matter.

  7. #7
    Join Date
    Jul 2001
    Location
    VA
    Posts
    2,801
    critical charge .....resi AC....... naahhhhhh

    besides..... most resi guys do not dump the hose charge between calls, they deal primarily with just a few refrigerants and have a set for each.
    ___________________________________________


  8. #8
    Join Date
    Jul 2000
    Location
    Northern Wisconsin
    Posts
    2,013
    Quote Originally Posted by emoney1971 View Post
    Be careful, many of the techs on this site and many in the field use one set of gauges for all residential refrigerant types. Which means they dump the charges on their gauges after each use. If your system is near critical and the tech has 6 foot hoses it could affect system performance.
    I dump the charge from my hoses after every check. Matter of fact I disconnect from the high side of the equipment first, open the high side of the guage to the crossover and then slowly open the low side of the guage to the crossover. IE: I put what liquid I took out of the system right back in. The only thing thing left in my guage set when im done is whatever gas it'll hold at the pressure of the low side. Anyone ever measured how much that is? Oh........ I run 5' hoses if someone is going to do the measurement.
    Use the biggest hammer you like, pounding a square peg into a round hole does not equal a proper fit.

  9. #9
    Join Date
    Sep 2006
    Location
    Southern California
    Posts
    86
    diminimus

  10. #10
    Join Date
    Jul 2001
    Location
    VA
    Posts
    2,801
    Yeah firecontrol.... I think every good tech does that.... I was just saying that you would not vent the hoses to atmosphere between calls.
    ___________________________________________


  11. #11
    Join Date
    Aug 2007
    Location
    Winter Haven, FL
    Posts
    4,379
    I belive that a 6' hose holds 1 oz of liquid refrigerant

  12. #12
    Join Date
    Nov 2005
    Posts
    1,350
    Relax everyone!!!!

    I said to be careful. I now all you amazing techs out there, like myself, dump your charge back into the system on the low side. Or I have a set of gauges for 410 and 22 with low loss fittings and valves, the best method IMO.

    There are however techs out there who don't and you lose a oz. or 2 every-time they hook up. Over time that adds up, and the last tech to hook up could be the one that drops that charge just enough to make a noticeable difference.

    The odds on this happening are small, so I will back down.
    I was trying to be technical and I will never do it again.
    I STARTED WITH NOTHING, AND I STILL HAVE MOST OF IT!

  13. #13
    Join Date
    Apr 2007
    Posts
    6,285
    23 grams (3/4 of oz) is what my scales said I hold in my liquid line thats full. Suction or low pressure side didn't show any difference.

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