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Thread: walk-in cooler

  1. #1
    Join Date
    Aug 2008
    Location
    Jacksonville florida
    Posts
    11

    walk-in cooler

    Had the evap coils frozen up on a r22 walk-in. After defrosting coils I checked the charge the sight glass was full. Unit pumps down when the t stat closes the liquid line solenoid. Had a (50) for superheat and (15) for subcooling. Took the bulb off the txv and heated in warm water and then ice water but temp leaving the evap coil never changed (68)This temp was taken where the bulb was mounted. Changed the powerhead today but still don't think its feeding enough to the evap. Here are temps and pressures...32 suction ,80 temp on roof at comp, 235 liquid , 105 temp. Condenser in 95 out 100. Box temp started at 80 was at 67 when I took temps and pressures. 3/8 liquid line reduced to 1/4 to TXV .The outlet is 1/2 sized up to 5/8 when leaving the cooler box. Box has (2 ) 7 foot 2 coil evaps , and the box is 12 X 10. There was some water on the floor that was being dryed up so I'm sure it wasn't all going to cool the box. Next guess is maybe a clogged filter screen in the TXV. Or am I expecting it to settle down before it reaches temp? Thanks again EX F M

  2. #2
    Join Date
    Sep 2005
    Location
    florida
    Posts
    5,495
    Quote Originally Posted by exhaust fan man View Post
    Had the evap coils frozen up on a r22 walk-in. After defrosting coils I checked the charge the sight glass was full. Unit pumps down when the t stat closes the liquid line solenoid. Had a (50) for superheat and (15) for subcooling. Took the bulb off the txv and heated in warm water and then ice water but temp leaving the evap coil never changed (68)This temp was taken where the bulb was mounted. Changed the powerhead today but still don't think its feeding enough to the evap. Here are temps and pressures...32 suction ,80 temp on roof at comp, 235 liquid , 105 temp. Condenser in 95 out 100. Box temp started at 80 was at 67 when I took temps and pressures. 3/8 liquid line reduced to 1/4 to TXV .The outlet is 1/2 sized up to 5/8 when leaving the cooler box. Box has (2 ) 7 foot 2 coil evaps , and the box is 12 X 10. There was some water on the floor that was being dryed up so I'm sure it wasn't all going to cool the box. Next guess is maybe a clogged filter screen in the TXV. Or am I expecting it to settle down before it reaches temp? Thanks again EX F M
    50 deg superheat
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  3. #3
    Join Date
    Aug 2007
    Location
    Winter Haven, FL
    Posts
    3,584
    If the box has two evaps, or how I am reading this...4 coils, what are the other evaps doing?

  4. #4
    Join Date
    Sep 2007
    Location
    State College, PA
    Posts
    893

    ???

    How can a 12 X 10 box have (2) 7 foot coils? Or am I reading something wrong here?

    Just curious? Trying to see this configuration.

    Thanks!
    Can someone please explain to me -
    Why is there never enough time to do it right the first time, but plenty of time to do it twice?


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  5. #5
    Join Date
    Aug 2008
    Location
    Jacksonville florida
    Posts
    11

    coil setup

    Coils are mounted on the ceiling in a box, with the fan ( blower wheel type) mounted at one end blowing air down the middle of the box. They are about 6 in tall by seven feet long. They are the long sides of the box. I guess I meant to say the coils have only 2 tubes in them, feeds from bottom U bends to the top tube, goes through, and then feeds the other evap.coil. Hope this helps . I am still thinking they are starved for liquid but not sure why. Cooler was working fine , but the kitchen was shut down for 6 months for renovation. So was turned off during that time. It was just turned on 2 weeks ago. Going to take the liquid line off TXV to see if there is a stainer-filter . I might put a pressure gauge on the liquid line to the TXV to see actual pressure to the valve. This 2 years at night AC- Refrig. school sure didn't teach what goes on in the real world. Thanks for replying to this post

  6. #6
    Join Date
    Dec 2006
    Location
    Middle Tennessee
    Posts
    11,347

    *

    This 2 years at night AC- Refrig. school sure didn't teach what goes on in the real world.
    just as any other trade, you can only learn so much in school

    learning is best done, on a one to one basis

    your at the stage of learning the trade where book theory is not much help

    actually, now your gonna need to mix a whole lot of common sense with very little theory



    .

  7. #7
    Join Date
    Aug 2007
    Location
    Winter Haven, FL
    Posts
    3,584
    I would try to adjust the valve and see what happens. If no change then I would replace the valve, drier and put in new refrigerant.

  8. #8
    Join Date
    Jul 2007
    Location
    alexandria va
    Posts
    138
    i cant recall ever seeing a walk in with a blower wheel setup. please post a pic. jbb

  9. #9
    Join Date
    Aug 2008
    Location
    Jacksonville florida
    Posts
    11

    cooler evap. set up

    Here is picture of cooler evap. And yes it's still not working right. But had to work on changing out a bad compressor. AAhh the JOYS of job security!!!!
    Attached Images Attached Images    

  10. #10
    Join Date
    Jul 2007
    Location
    alexandria va
    Posts
    138
    its looks like your going about the call the right way. its looks like a low profile that the pan has been replaced. there was probably 2 or 3 fan motors facing down in the middle of the pan . looks like a rig job but i may be wrong. good luck with that. hard from comp . thanks for the pics. jbb

  11. #11
    Join Date
    Jun 2007
    Posts
    820
    Quote Originally Posted by jtrefrig View Post
    its looks like your going about the call the right way. its looks like a low profile that the pan has been replaced. there was probably 2 or 3 fan motors facing down in the middle of the pan . looks like a rig job but i may be wrong. good luck with that. hard from comp . thanks for the pics. jbb
    yup, this is funny, i was just about to say this as well, it is one of those low pro evap coils, you can tell that the bottom panel is newer then the coil, man this is a crazy mickey mouse job.
    I will take a bullet for my Veto LC tool bag!

  12. #12
    Join Date
    Sep 2005
    Location
    florida
    Posts
    5,495
    Look's like a hack job for sure.
    I love the smell of phosgene first thing in the morning:

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    Educational forums are open.

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  13. #13
    Join Date
    Jun 2006
    Location
    Texas
    Posts
    497
    Never seen blower on any walkin cooler or freezer. It can't be right, you would have to drop the drain pan to clean the coil.

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