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Thread: Help

  1. #1
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    Help

    I've got a walk in. 30 x 10 x 8. 2 3.5 s and two five fan evaps. Everything is wet. This is a real life question. help.

  2. #2
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    What is 23.5?
    Low ned temp
    Cond unit and evap #’s
    Refrigerant
    Operating pressures
    Operating temperature
    SH & SC

  3. #3
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    (2) 3.5 HP condensing units. Scroll.

  4. #4
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    Thread Starter
    404A

    TD maybe?

  5. #5
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    I'm guessing this is a cooler.

    Tell us what you see:

    Is everything running?

    Are the sight glasses full?

    Are the coils froze up?

    Are the condensers clean?

    Are the evaps clean?

    What pscmsg said.

  6. #6
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    According to this you should have 18,000 - 20,000 BTU capacity for a cooler.

    2-3 1/2 tons may be too large........we need the Make & Model #'s
    Attached Images Attached Images

  7. #7
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    If the system is oversized the temperature will pull down and be satisfied before it has had enough time to properly dehumidify. If the system was designed with a typical 10°F or 15°F TD, the lack of run time, like 10 hrs/day instead of the typical design of 18-20 hrs/day, will drive the RH way up.

    Try staging the two systems so one runs to maintain normal box conditions while the other is there for heavy loads, high ambients , etc.

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  9. #8
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    I wonder if the box is new and has no load? If it’s in a kitchen use it in real scenario ie leave the door open
    Honeywell you can buy better but you cant pay more

    I told my wife when i die to sell my fishing stuff for what its worth not what i told her i paid for it

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  11. #9
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    We suspected it had a low load. Also that the slab it is on had an issue with being wet. We have sized these boxes before and they all work fine.

  12. #10
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    Double post Fred Flinstone fingers.

  13. #11
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    How are you controlling the two condensing units? Are they on separate temperature controls or are they on a single control?

    The problem appears to be insufficient load and too much cooling capacity running at the same time. You mentioned in another thread that this box is sized for a heavy beer load which isn't there t this time, so therein lies you problem.

    If you offset the setpoints of the two condensing units by a couple of degrees, the one unit will run longer to satisfy the temperature and dehumidify better in the process. It's a simple solution and the best and most common method of controlling such a setup.

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  15. #12
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    Quote Originally Posted by icemeister View Post
    How are you controlling the two condensing units? Are they on separate temperature controls or are they on a single control?

    The problem appears to be insufficient load and too much cooling capacity running at the same time. You mentioned in another thread that this box is sized for a heavy beer load which isn't there t this time, so therein lies you problem.

    If you offset the setpoints of the two condensing units by a couple of degrees, the one unit will run longer to satisfy the temperature and dehumidify better in the process. It's a simple solution and the best and most common method of controlling such a setup.
    brilliant, it never stops .... that is a really good idea

  16. #13
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    That is the best idea I believe, however each condensing unit is pair with a 5 fan evaporator so half the display doors will be warmer than the other side if the temp controls are set apart too far.

  17. #14
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    Quote Originally Posted by jmlandru View Post
    That is the best idea I believe, however each condensing unit is pair with a 5 fan evaporator so half the display doors will be warmer than the other side if the temp controls are set apart too far.
    Display doors ? Did you mention that earlier ?

  18. #15
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    Quote Originally Posted by jmlandru View Post
    That is the best idea I believe, however each condensing unit is pair with a 5 fan evaporator so half the display doors will be warmer than the other side if the temp controls are set apart too far.
    This depends on how the evaporator are piped. Most coolers that I've seen and installed that have four evaporators and two condensing units have the evaporator interlaced so every other evaporator is on the other system.

    If your's are not piped this way, it's not usually a major job to repipe them so they can be staged without one end of the box being warmer than the other.

  19. #16
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    They do make a Lead Lag controller that with help with that problem. 1st on 1st off. Ill see if i can find the link

  20. #17
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    Quote Originally Posted by pecmsg View Post
    They do make a Lead Lag controller that with help with that problem. 1st on 1st off. Ill see if i can find the link
    When you looked up the box load did it included glass doors ? I haven't looked at that yet.

  21. #18
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    Quote Originally Posted by icemeister View Post
    This depends on how the evaporator are piped. Most coolers that I've seen and installed that have four evaporators and two condensing units have the evaporator interlaced so every other evaporator is on the other system.

    If your's are not piped this way, it's not usually a major job to repipe them so they can be staged without one end of the box being warmer than the other.
    Icemeister, I read that he had 2-5 fan evaporators.

  22. #19
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    Quote Originally Posted by VTP99 View Post
    Icemeister, I read that he had 2-5 fan evaporators.
    Yes, you're right.

    I had it in my head that each unit had a pair of evaporators. Duh...

  23. #20
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    Quote Originally Posted by icemeister View Post
    Yes, you're right.

    I had it in my head that each unit had a pair of evaporators. Duh...
    You still bring up a good solution for that scenario.

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