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  1. #1
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    What is the difference between 407A & 407C ?

    Yes; I know that one is for A/C and the other for refrigeration - but what I want to know is WHY?

    What is the difference between the two refrigerants?

    What difference does it make if I use 407A in an air conditioning application or use a 407C in a refrigeration application?
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  2. #2
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    407a is better at low temp than c is. Also slightly lower discharge temps.
    Knowledge is knowing that a tomato is a fruit. Wisdom is knowing not to put it in a fruit salad.

  3. #3
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    Jan 2013
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    When a blend has different letters after the same number (A and C), it means they have different percentages of the same refrigerants used in the blends. They both have the same refrigerants in their blends, just different ratios.

    My guess is 407A is blended to work better in low temp, whereas 407C is more toward medium temp, because of differences in pressure/temp relations.

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  5. #4
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    I'm not a chemist or know exactly what it is but i think that 407a has something added to the blend to help with lowering the discharge temperatures on higher compression ration(MT/LT refrigeration, what ever it is i believe lowers the efficiency of the refrigerant a bit and also raises the GWP ratio of the gas,

    407c is a bit more efficient and has lower GWP but only is good for HT refrigeration, but no good for MT/LT due to discharge temps

    i could be completely wrong but thats what i'm going with for now hahaha

    Mike
    Sig removed by mod. G-Rated site

  6. #5
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    wow 3 answers at once hahahahaha
    Sig removed by mod. G-Rated site

  7. #6
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    Thread Starter

    So high DSH is my only concern ?

    Anybody know How High ? <g>

    How much higher the DSH is with 407C as versus 407A ?
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  8. #7
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    Thread Starter
    If you all recall; the only reason for R-502 was that R-22 ran excessive DSH on LT applications. And this was a real problem with mineral lube oils as thermal oil breakdown would coke up the valves. Synthetic oils would have also solved the problem but Dupont makes refrigerants and not lube oils. <g>

    I don't think POE oils like high temps either - although they don't coke, I do think something else comes out of them (whatever clogs up cap tubes) when they get overheated.

    I wonder if there is any synthetic refrigeration oil which will both play nice with the 400 grade refrigerants And remain stable at high temps?

    Any ideas?
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

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  10. #8
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    May 2010
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    We have a couple stores with 407C for medium and low temp.

  11. #9
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    May 2003
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    Actually POE has a better tolerance for high temperatures. Mineral oil starts to decompose at 350F and POE starts to decompose at 400F.

    I've attached a spreadsheet showing the chemical makeup of some of the popular R-22 replacements. It's the R-32 and R-125 (lower boiling point refrigerants) which give R-407A and R-407F more capacity than R-407C. It's also the higher percentage of R-32 which causes the R-407F to have discharge temperatures much closer to R-22....not a good thing.
    Attached Images Attached Images

  12. #10
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    Jun 2013
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    I have heard that 407c doesn't have that great of oil return so using on a rack with an oil seperator is why it is for supermarkets. 407a has a better oil return (mixing ability). Kinda like r422d (I think) has crapy oil return and must be ran with about a 50/50 poe and alk.

  13. #11
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    Quote Originally Posted by bunny View Post
    It's also the higher percentage of R-32 which causes the R-407F to have discharge temperatures much closer to R-22....not a good thing.
    I just completed 2 stores (4 racks) from R-22 to R-407F.

    Under R-22, liquid injection would cycle.

    Under R-407F, liquid injection is not even needing to run.

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  15. #12
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    May 2010
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    Didn't even know there was a 407F

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  17. #13
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    Sep 2002
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    I just spoke with my supply and they only stock 2 jugs 407F , and said they almost never sell it

    Anyone use it ?

    Hey Poodle , its been a few years , are you currently stocking both 407 A and C ?

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