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Thread: subcooling

  1. #1
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    subcooling



    how do you measure subcooling



  2. #2
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    Re: subcooling

    you convert the head pressure reading to tempreture then messure the liquid line tempreture the dif between the saturated tempreture and actual temp is subcooling
    Last edited by martinw58; 27-05-2010 at 10:34 PM. Reason: extra info

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    Re: subcooling

    read Refrigeration 101: by Gary

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    Re: subcooling

    Quote Originally Posted by martinw58 View Post
    you convert the head pressure reading to tempreture then messure the liquid line tempreture the dif between the saturated tempreture and actual temp is subcooling
    This not quite correct, actual sub-cooling you need to measure the liquid pressure (and convert to a saturated temperature) and measure the actual liquid temperature, the difference between the temps is the actual level of sub cooling. Sorry for being so perdantick, as this is one of my pet subjects.

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    Re: subcooling

    Yes oldtimer
    madfridgie is very correct as usual. A few more tips - If no access point is available at outlet of cond or liquid line allow for pressuredrop through condenser of more than about 5psi. There is nothing like an accurate measurement so get your self a superheat calculation kit like yellow jacket (ritchie) and measure the refrigerant temp and pressure directly. Even if you have to pump down the unit and weld in a schrouder port anywhere on the liquid line.

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    Re: subcooling

    Quote Originally Posted by Tesla View Post
    Yes oldtimer
    madfridgie is very correct as usual. A few more tips - If no access point is available at outlet of cond or liquid line allow for pressuredrop through condenser of more than about 5psi. There is nothing like an accurate measurement so get your self a superheat calculation kit like yellow jacket (ritchie) and measure the refrigerant temp and pressure directly. Even if you have to pump down the unit and weld in a schrouder port anywhere on the liquid line.

    hes asking about subcooling not superheat

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    Re: subcooling

    Cool tony--1
    But just check it out first - the superheat calc kit measures sub cooling directly as well as superheat.

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    Re: subcooling

    Quote Originally Posted by Tesla View Post
    Cool tony--1
    But just check it out first - the superheat calc kit measures sub cooling directly as well as superheat.
    That we call humor, my friend.
    Now, when I am officialy citizen off EU, I am looking for decent job! For any job offer please check my profile!

  9. #9
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    Re: subcooling

    Quote Originally Posted by mad fridgie View Post
    This not quite correct, actual sub-cooling you need to measure the liquid pressure (and convert to a saturated temperature) and measure the actual liquid temperature, the difference between the temps is the actual level of sub cooling. Sorry for being so perdantick, as this is one of my pet subjects.
    sir how can i know if the subcooling measure are correct compare to the superheat of evaporator

  10. #10
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    Re: subcooling

    Quote Originally Posted by tony--1 View Post
    hes asking about subcooling not superheat
    sorry sir im just new im quite thinking the balances of both measurement ,like in multi stage.

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    Re: subcooling

    Quote Originally Posted by karas View Post
    sir how can i know if the subcooling measure are correct compare to the superheat of evaporator
    Kamusta (tagalog not to good)
    Sub cooling has no direct relationship to evaporator superheat. If you have no sub cooling at the expansion valve, then you are likely to have a mix of liquid and vapour. The mix will will reduce the mass flow through the valve, causing the evaporator to be starved (not enough liquid) if the evap is starved then you will have high superheat.
    I hope this is what you meant?

  12. #12
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    Red face Re: subcooling

    The others have measuring subcooling correct, but system needs to be fully loaded, all cond. fans running. May have to manipulate low ambient controls if cold enough outside.

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