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Thread: Low Pressure vs. High Pressure Refrigerants

  1. #1
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    Exclamation Low Pressure vs. High Pressure Refrigerants

    What are the advantages and disadvantages of using a low pressure refrigerant as compared to a high pressure refrigerant?
    I am currently a student and am wanting to learn why someone would choose one over the other. Thanks in advance.

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    In my opinion it is all about situation. With the exception of the r22 phase out. The epa has said r22 is depleting our ozone, hence they are phasing it out and only a few refrigerants work in its place. 407c is a good retrofit, but 410A(higher pressure) is almost the new standard for creature comfort ac applications (but not a retrofit!!!) since they decided to phase out r22. Low pressure refrigerants are more for coolers/freezers. Others may chime in as well to further define, and I hope they do!

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    Quote Originally Posted by fdreher23 View Post
    What are the advantages and disadvantages of using a low pressure refrigerant as compared to a high pressure refrigerant?
    I am currently a student and am wanting to learn why someone would choose one over the other. Thanks in advance.
    Low pressure machines a less likely to leak refrigerant than high pressure, low pressure machines are easy to service and in many cases a sensor or seal can be replaced without evacuating the refrigerant, low pressure machines don't need to ASME stamped etc. I prefer to work on low pressure!
    There is not better place for the working men than the union! 100% UA the only HVAC union!

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    Quote Originally Posted by Bombboy90 View Post
    Low pressure refrigerants are more for coolers/freezers. Others may chime in as well to further define, and I hope they do!
    I have never seen a low pressure cooler or freezer!
    There is not better place for the working men than the union! 100% UA the only HVAC union!

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    Really depends on the definition of low pressure refrigerant.

    404A is low pressure relative to 410A.
    I do a triple evac with nitro to remove non condensables.

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    Quote Originally Posted by BBeerme View Post
    Really depends on the definition of low pressure refrigerant.

    404A is low pressure relative to 410A.
    Unless something has recently changed,pretty much all the way back since air conditioning was invented low pressure = bellow atmospheric pressure (14.7psia)
    There is not better place for the working men than the union! 100% UA the only HVAC union!

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    Quote Originally Posted by valdelocc View Post
    Unless something has recently changed,pretty much all the way back since air conditioning was invented low pressure = bellow atmospheric pressure (14.7psia)
    You would need to ask the original poster if that is the low pressure he is asking about.
    I do a triple evac with nitro to remove non condensables.

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    Quote Originally Posted by BBeerme View Post
    You would need to ask the original poster if that is the low pressure he is asking about.
    I dont need to ask anything to anyone, there is only one definition for "low pressure refrigerant" if it does not fit that mold then is NOT low pressure,plain and simple!
    There is not better place for the working men than the union! 100% UA the only HVAC union!

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    Quote Originally Posted by valdelocc View Post
    I dont need to ask anything to anyone, there is only one definition for "low pressure refrigerant" if it does not fit that mold then is NOT low pressure,plain and simple!
    It is very likely his instructor is calling 22 low pressure and 410 high pressure.
    I do a triple evac with nitro to remove non condensables.

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    Quote Originally Posted by BBeerme View Post
    It is very likely his instructor is calling 22 low pressure and 410 high pressure.
    In that case he needs to find another instructor !
    There is not better place for the working men than the union! 100% UA the only HVAC union!

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    Quote Originally Posted by BBeerme View Post
    It is very likely his instructor is calling 22 low pressure and 410 high pressure.
    What does that make R-11?

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    Quote Originally Posted by valdelocc View Post
    In that case he needs to find another instructor !
    I've learned through the years when dealing with a rookie, you generally have to ask a couple of questions to determine what they are really asking. For example, just yesterday . . .

    A co-worker called me and said he could not get a pulley off of a shaft, and his puller was just breaking the pulley. I asked him if the bolts were parallel to the shaft or perpendicular. He replied, perpendicular, not parallel.

    So I drove over to where he was and found that the bolts were parallel to the shaft, D'oh! Had to show him that you do not need a puller for those type of pulleys. For what it is worth, he was in an area that would not allow FaceTime or for him to message me a photo of the pulley.
    I do a triple evac with nitro to remove non condensables.

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    Quote Originally Posted by pecmsg View Post
    What does that make R-11?
    LOL

    410 is low pressure relative to 508. Or how about 14?
    I do a triple evac with nitro to remove non condensables.

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    Quote Originally Posted by BBeerme View Post
    LOL

    410 is low pressure relative to 508. Or how about 14?
    With your logic they are all low pressure compared to CO2! The definition is clear and most rookies I get from the hall or trade school know the lingo!
    There is not better place for the working men than the union! 100% UA the only HVAC union!

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    Quote Originally Posted by valdelocc View Post
    With your logic they are all low pressure compared to CO2! The definition is clear and most rookies I get from the hall or trade school know the lingo!
    Go back read the original post. It is asked in such a manner that you actually have a choice in using a low pressure refrigerant or a high pressure refrigerant. So I seriously doubt they are talking about what is commonly referred to in the trade as a low-pressure refrigerant.
    I do a triple evac with nitro to remove non condensables.

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    Quote Originally Posted by BBeerme View Post
    Go back read the original post. It is asked in such a manner that you actually have a choice in using a low pressure refrigerant or a high pressure refrigerant. So I seriously doubt they are talking about what is commonly referred to in the trade as a low-pressure refrigerant.
    The original post seems clear enough to me yet somehow you are speculating different.
    There is not better place for the working men than the union! 100% UA the only HVAC union!

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    Quote Originally Posted by valdelocc View Post
    The original post seems clear enough to me yet somehow you are speculating different.
    And with good reason.
    I do a triple evac with nitro to remove non condensables.

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    Quote Originally Posted by BBeerme View Post
    And with good reason.
    Good reason? maybe in California !
    There is not better place for the working men than the union! 100% UA the only HVAC union!

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    Quote Originally Posted by valdelocc View Post
    Good reason? maybe in California !
    Depends what type of school this guy is in. They call 410 a high-pressure refrigerant. So by definition, 22 is low pressure. At least for these trade schools.
    I do a triple evac with nitro to remove non condensables.

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    Quote Originally Posted by BBeerme View Post
    Depends what type of school this guy is in. They call 410 a high-pressure refrigerant. So by definition, 22 is low pressure. At least for these trade schools.
    Nobody but you call 22 low pressure!
    There is not better place for the working men than the union! 100% UA the only HVAC union!

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