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Thread: 134a

  1. #1
    Join Date
    Jun 2012
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    134a

    I am an inexperienced tech and have never worked with 134a. Today I was asked to check out a rooftop unit with 134a. what are the normal operating pressures for 134a? I know r-22 is around 70 to 75 on the low side and around 225 on the high side.

  2. #2
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  3. #3
    Join Date
    Jun 2012
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    IL.
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    I'm guessing it was for a cooler? it is on a resturaunt.

  4. #4
    chiller?

  5. #5
    Join Date
    Jun 2012
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    IL.
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    I don't know. my boss told me to connect my guages and tell him the pressures. he wanted me to do this because he saw the suction line was frosted. I am sorry i could not be more specific.

  6. #6
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    IL.
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    when I asked him what they should be he told me that it depends on the size of the unit. I am beginning to think I know more about HVAC than he does. either way I am beginning to doubt him. and will surely have more questions in the future.

  7. #7
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    So, what were the pressures?

    Now this is making a bit more sense...


    Did you take any measurements beyond pressures?

  8. #8
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    Mid-Mo
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    Wow?? Help us help you. Model? What it is? Pictures? Anything?!

  9. #9
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    Apr 2012
    Location
    winnipeg
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    134a my least favorite refrigerant....... I hate it...........
    it was working.... played with it.... now its broke.... whats the going hourly rate for HVAC repair

  10. #10
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    Jun 2012
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    IL.
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    I apologize for the lack of details. this is my first post. I believe it was close to 2 tons. Again I apologize in advance for my poor memory. the label was worn and I almost mistook it for a 22 unit like the one next to it. I believe the pressures were like 25 psi on the low and 150? on the high. My boss told me to charge it so I did. just enough to melt the frost on down the line but it melted slowly. he told me that was good. but I didn't feel in my gut that he knew.

  11. #11
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    Apr 2012
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    winnipeg
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    well ..... I assume he new something....
    it was working.... played with it.... now its broke.... whats the going hourly rate for HVAC repair

  12. #12
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    Jan 2004
    Location
    Lancaster PA
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    I think you mean the condenser was on the roof.

    Learn to ignore the pressure readings as a way to check charge. And learn to read and use saturation temps.
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  13. #13
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    Nov 2006
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    Quote Originally Posted by roosel View Post
    I apologize for the lack of details. this is my first post. I believe it was close to 2 tons. Again I apologize in advance for my poor memory. the label was worn and I almost mistook it for a 22 unit like the one next to it. I believe the pressures were like 25 psi on the low and 150? on the high. My boss told me to charge it so I did. just enough to melt the frost on down the line but it melted slowly. he told me that was good. but I didn't feel in my gut that he knew.
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