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evap. coil capacity

Discussion in 'Refrigeration' started by R/HVAC, Dec 26, 2017.

  1. R/HVAC

    R/HVAC selfemployed

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    This discussion has come up many times on my end and there seem to be different thoughts on sizing. This is not a test, I just want to here what others say. Thanks in advance
    The freezer coil capacity is 6,000 BTU@-10f @ 10º TD. It will be used for a 35º cooler. What BTU capacity would you give it @25ºf @ 10º TD.
     
  2. crackertech

    crackertech assholiness *

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    If I knew anything I would comment :D
     
  3. pecmsg

    pecmsg Junior my ASS

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    A condensing unit Heatcraft R*H200M44 shows 6550 BTU's @ -10°f also shows 17,420 @+25°f

    If that helps
     
  4. crackertech

    crackertech assholiness *

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    Of course coil capacity will increase with a higher temp:chairshot:
     
  5. crackertech

    crackertech assholiness *

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    Might have to adjust the meeting device
     
  6. R/HVAC

    R/HVAC selfemployed

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    Don't let that stop you ;)
     
  7. frozensolid

    frozensolid Psychologist's Dream

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    250-300 BTU per degree rise in coil temp. General rule of thumb. But you know how rules of thumb go.
     
  8. R/HVAC

    R/HVAC selfemployed

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    But what capacity would you give the evap. coil?
     
  9. pecmsg

    pecmsg Junior my ASS

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    I would guess the same! If the compression ratio goes up so does the evaporators capacity!

    E-Mail Ice. He'll know that shit off the top of his head, i still have to search.
     
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  10. crackertech

    crackertech assholiness *

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    We use to do this every year turn a walk in freezer into a cooler we just had to adjust the sorit valve good to go
     
  11. crackertech

    crackertech assholiness *

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    And I could do that from home most of the time :D
     
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  12. R/HVAC

    R/HVAC selfemployed

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    Where do I find that in print or a calc. in I&O literature from Mfg. Your inside the ball part, and pretty close to figures I have heard. I just ask people I give rules of thumb to not to include my name when repeating.
     
  13. R/HVAC

    R/HVAC selfemployed

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    Dennis - just to be sure are you saying, -10 to 25º = 35 x 300 = 10,500. Or 6,000 + 10,500= 16,500
     
    Last edited: Dec 26, 2017
  14. frozensolid

    frozensolid Psychologist's Dream

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    Yes the second one start with what you know and add BTU per degree. Not the rule of thumb but this will answer you if you like math. :)

    Total Capacity (BTU/hr) = 4.5 x CFM x (Hewb – H₁wb) or Cooling BTUs = CFM x ∆h x 4.5
     
  15. crackertech

    crackertech assholiness *

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    Just like I said :D
     
  16. flange

    flange Act like you care and do SOMETHING!!

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    please ship me a few of those compressors you are using at 100 hp each, unless you meant compressor volumetric EFFICIENCY

    from my experience, when compression ration goes up, that usually means a lower evap temp which reduce capacity. going from a 35 degree evap, to say 5 degree, you think it does more workypoo?

    5 suction, 200 head, compression ratio is 10:1

    35 suction 200 head CR is 4:1
     
  17. crackertech

    crackertech assholiness *

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    He’s so old he’s senile
     
  18. pecmsg

    pecmsg Junior my ASS

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    Oooops
     
  19. flange

    flange Act like you care and do SOMETHING!!

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    just trying to keep the information factual. I think a fair amount of noObs read this site and should get proper information, especially since most of us are "old guys" who know better, but forget more than we remember.
     
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  20. crackertech

    crackertech assholiness *

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    That’s true