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  1. #14
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    May 2005
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    The honey comb looks dirty but we blew it out, I can hardly feel any air at all//but its clean and all 3 fans are doing their job..

    I don't have a fpm tool..I didn't see any frost on the outlet of the tex, but its tight…yes the compressor is just under rated amps.

    All I got out of the TEX from full open to just about closed was 7-10* of super heat at the compressor…the suction temp went form 44* to 36*
    Let's give nukes a chance.

  2. #15
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    May 2014
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    I see a fair amount of Hussmann units. Is that 400 fpm a good rule of thumb at the honey comb? Never heard of it before.



    Quote Originally Posted by hevysrf View Post
    Do have you 400 fpm air at the honey comb? Is the honey comb clean? That case is old enough that the plenums may be rusted and collasped, evap fan blades wrong, evap motors out or wrong rotation. Are all the sheet metal covers over the evap in place? Many hussman med temp cases had an expanded metal grid in the plenum that always clogs with dust.

    Confirm your airflow. Let us know your pressure and temp reading at the outlet of the evap. Give us a number on the liquid line temp. Is there a frost pattern on the tex or distributor, and is the compressor at rated amps?
    These are old school cases, look at all your basics first.

    On an entirely different note, what kind of case is this? I'm not familiar with the B9D cases. Is it an open air by any chance?

  3. #16
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    This is a open deli case, 12' long, and I hate it. Evap and fans are on top.
    Let's give nukes a chance.

  4. #17
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    Mar 2013
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    B9D is an old monster multi deck dairy,energy hog. Evap coil is in the top of the case, awkward fan arrangement, top rear of case, nasty to change motors. Every chain I visit scrapped them 20 years ago. I've seen case specs 200 to 600 fpm, 400 is going to be minimum for an old top discharge multi deck in my opinion. I use an old Alnor jr, I don't know if its accurate, but its great to compare cases and its small enough to take everywhere.

    Low superheat, high discharge air temp screams airflow to me.
    Attached Images Attached Images  

  5. #18
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    May 2014
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    Ah. Saw the post when you started it, but didn't have any input since I didn't know what you were working on. Took me a bit to figure out open air cases. Here is the single most important thing I look at when an open air case won't pull down: Any disturbance to the air curtain.

    Happens all the time. Re-ducting, repair to A/C [aka new blower etc.], open doors, other in store equipment, even cleaning a supply register with adjustable louvers.

    There are a couple of quick checks you can do. First, get out a strip of toilet paper maybe five feet long. Then hold one end above your head and slowly walk around the case. This will tell you what is happening to the air around the case.

    Next, measure the 'return' air. It's pretty common for me to find a 15*F split between the supply and return air. If you've got something close to that 15*F, but the air returning to the evap is too high, then you'll never get the case cold enough.

    Start with those two things and see what you find.


    Quote Originally Posted by primmers View Post
    This is a open deli case, 12' long, and I hate it. Evap and fans are on top.

  6. Likes kamersoutdoor liked this post.
  7. #19
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    May 2014
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    Just to clarify something in this post.

    If your split is too high, and it is due to the air curtain being disturbed, you'll never get the case to pull down.

    A couple months ago I almost condemned a compressor. Took me two hours to realize that the air curtain was being disturbed. Minor modifications to things that had nothing to do with the open air case, and within minutes the temp started pulling down in the open air case.


    Quote Originally Posted by BBeerme View Post
    Ah. Saw the post when you started it, but didn't have any input since I didn't know what you were working on. Took me a bit to figure out open air cases. Here is the single most important thing I look at when an open air case won't pull down: Any disturbance to the air curtain.

    Happens all the time. Re-ducting, repair to A/C [aka new blower etc.], open doors, other in store equipment, even cleaning a supply register with adjustable louvers.

    There are a couple of quick checks you can do. First, get out a strip of toilet paper maybe five feet long. Then hold one end above your head and slowly walk around the case. This will tell you what is happening to the air around the case.

    Next, measure the 'return' air. It's pretty common for me to find a 15*F split between the supply and return air. If you've got something close to that 15*F, but the air returning to the evap is too high, then you'll never get the case cold enough.

    Start with those two things and see what you find.

  8. #20
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    Mar 2013
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    Definitely check for disturbed air curtain, also make sure he has shelves in the case along with the bottom pans. When they remove shelves to put in hanging racks, it destroys the airflow. Remove the bottom pans or block returns with product or price tags and the air will short cycle.
    Last edited by hevysrf; 05-02-2015 at 09:18 PM.

  9. #21
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    May 2005
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    I just came back from the system…the return vent ( knee high ) can suck a plastic produce bag, how ever up above,, not much..the honey comb seems to be clean.. I need to replace the pump down solenoid before I can continue,,
    theres nothing disturbing the air around the case.
    Let's give nukes a chance.

  10. #22
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    Jul 2000
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    That case is at least 50 years old.

    You blew out the honeycombs, but did you pull them and really clean them? The coil, fans and plenums have probably never been cleaned either. Those can (and do) get so filthy that the airflow becomes seriously restricted.

    I suspect you will find what killed the last compressor.

  11. #23
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    May 2005
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    I will pull the honey combs tomorrow and spit shine them.. the coil looks good, almost new..

    thanks for all the help guys…
    Let's give nukes a chance.

  12. #24
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    Jan 2010
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    Are there ceilings fans running close to the case?

  13. #25
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    No air movement at all….Im wondering if
    I have oil in the evaporator now??

    no superheat to speak of no temp differential…..in the evap.
    Let's give nukes a chance.

  14. #26
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    the honey comb is about 2" thick and its open, but I did blow it out and got some trash..

    The thing Im thinking now is is putting a different fan blade to draw more air..

    theres a slight air movement on the top vent, and a decent one on the lower vent..

    I know cold air falls, so maybe the fan blade thing is mute..
    Let's give nukes a chance.

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