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  1. #1
    Join Date
    Mar 2004
    Location
    Chester County PA
    Posts
    421
    I've never done it before. I've always either weighed the charge in or used the pressure/temp. at the coils.

    So I would like to know how to do it the "best" way.

    From what I understand I take a temperature reading on the liquid line going into the evap. Then I take a temperature reading on the vapor line 6 inches from the evaporator outlet. I should have a difference of 8-12 degrees F.

    Is this correct?

    Thanks all,
    -smoke-
    "That motor's done, he let the factory smoke charge out!"

  2. #2
    Join Date
    Mar 2004
    Location
    Windsor, ON Canada
    Posts
    168
    Superheat is suction line temp minus saturated suction temp.
    A temp. reading on the liquid line is used in subcooling recordings. The best place to take the superheat reading is at the inlet of the compressor. Most compressors are rated to have about 10F superheat.

  3. #3
    Join Date
    Apr 2003
    Location
    Levittown, PA
    Posts
    818

    Lightbulb

    Sometimes when I consider what tremendous consequences come from little things, I am tempted to think there are no little things!

  4. #4
    Join Date
    Jan 2004
    Location
    Earth
    Posts
    4,879
    Remember only charge cap tube systems on superheat.

    TXVs use subcooling or sight glass.
    A Diamond is just a piece of coal, that made good under pressure!

  5. #5
    Originally posted by frozensolid
    Remember only charge cap tube systems on superheat.

    TXVs use subcooling or sight glass.
    And SUBCOOLING method is the better of the two. Especially on the new blends.



    If somebody would have told us in detail what we would endure in this trade once real freon was outlawed and only blends were available .... we could have titled the book; "A Brave New World!"


  6. #6
    Join Date
    Dec 2003
    Location
    Nevada
    Posts
    1,815
    Sounds like someone listened in tech school! This was the way we were taught (in the AF) it works, but make sure you read the manufacturers literature because sometimes they want 20 degrees or more.
    Quote
    “Engineers like to solve problems. If there are no problems handily available, they will create their own." Scott Adams

    "We can't solve problems by using the same kind of thinking we used when we created them."
    Albert Einstein

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