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  1. #1
    Join Date
    Feb 2009
    Location
    , had my own business for 30 years
    Posts
    351

    Partially frozen evap, (Thick ice bottom-1/3)

    What are some causes for a partially frozen evaporator (besides low charge) on a walk-in evap, 3 fan Larkin food cooler, full charge 404, was running fine, thermostat set on 38, 5 degree differential.
    Got a call on this, haven't been there yet. Customer defrosted, but may call me back.
    I know that's not much information, but it's pretty much all I have.
    I have done all commercial HVAC, not allot of refrigeration, maybe 20%.
    Thanks.

  2. #2
    Join Date
    Jan 2001
    Location
    So.Cal
    Posts
    443
    TXV probably needs to be adjusted, but if you have never done comm refrig you are in for a fun day of tweeking.

  3. #3
    Join Date
    Feb 2009
    Location
    , had my own business for 30 years
    Posts
    351
    Probably not so much fun, but thanks for responding.
    I will drop by the store and check on it.

  4. #4
    Join Date
    Jul 2000
    Location
    Guayaquil EC
    Posts
    10,328
    Uneven icing of the evaporator coil like that can be due to an improper distributor nozzle. An oversized nozzle can lead to uneven distribution...essentially overfeed some circuits and underfeeding others.

    More than likely though, your ice buildup is a result of incomplete defrosting.

    I'm assuming this sytem has no defrost timeclock and relies strictly on the off-cycle time to clear away frost buildup. If ALL of the frost is not cleared off, it will re-freeze and become hard ice.

    Add a defrost timeclock and set it up for three 30-40 minute defrosts per day.

  5. #5
    Join Date
    Jul 2007
    Location
    alexandria va
    Posts
    138
    if its ice not frost make sure your drain is clear. jbb

  6. #6
    Join Date
    Sep 2005
    Location
    florida
    Posts
    5,506
    X2 check the defrost and the drain line first.
    I love the smell of phosgene first thing in the morning:

    To apply for professional membership click here


    Educational forums are open.

    If you would like to submit a link or an article or other related info to the EF. click here

  7. #7
    Join Date
    May 2004
    Posts
    1,853
    Since this is on the same subject, i have a similar question. What causes the Txv and distributer tubes to freeze to a ball of ice without the coil freezing up? I run into this alot on walk-in freezers.

  8. #8
    Join Date
    Jul 2009
    Location
    eastlake,ohio
    Posts
    73
    You're really going to need to know the pressures.High pressure the condenser is dirty or the TXV strainer is dirty,Or you're probably low on refrigerant,Or a evap fan is not working,and of course they might of left the door open all weekend or bad seals.......

  9. #9
    Join Date
    Feb 2008
    Location
    California
    Posts
    2,066
    Quote Originally Posted by 270wsm View Post
    Since this is on the same subject, i have a similar question. What causes the Txv and distributer tubes to freeze to a ball of ice without the coil freezing up? I run into this alot on walk-in freezers.
    This could happen with a starved TEV. the Liquid is literally flashing to a vapor inside of the TEV.

    Or it could be normal and the frost/ice dose not melt in defrost because usually the TEV/distributer tubes are in an enclosed section of the evaporator coil that dose not have heating elements. where as the actual evaporator is in direct contact with the heating elements.

  10. #10
    Join Date
    Nov 2005
    Location
    Haymarket VA
    Posts
    642
    Quote Originally Posted by jtrefrig View Post
    if its ice not frost make sure your drain is clear. jbb
    jtt x2
    patriot1

  11. #11
    Join Date
    Jul 2002
    Location
    NY
    Posts
    1,886
    Quote Originally Posted by 270wsm View Post
    Since this is on the same subject, i have a similar question. What causes the Txv and distributer tubes to freeze to a ball of ice without the coil freezing up? I run into this alot on walk-in freezers.
    Moisture in the system.
    Not what it use to be

  12. #12
    Join Date
    Sep 2012
    Location
    Loma Linda, California
    Posts
    1

    Larkin Walk in cooler freezing up top section only

    I started working at a restaurant performing services and the owner asked me to look at their Larkin walk in cooler that was only at 50 degrees. Found large section of inside and outside of coils in walk in frozen up, removed all ice, rooftop unit very low on freon, recharged got temp down to 38 degrees, 3 days later all still ok and coils still clear, 1 week later top section inside and outside frozen up, charge ok but temp down to 50 degrees, is this not defrosting and where could I locate the defroster I cannot find it anywhere. Model # is 2 blade low profile

  13. #13
    Join Date
    Sep 2005
    Location
    florida
    Posts
    5,506
    Quote Originally Posted by MPHPS View Post
    I started working at a restaurant performing services and the owner asked me to look at their Larkin walk in cooler that was only at 50 degrees. Found large section of inside and outside of coils in walk in frozen up, removed all ice, rooftop unit very low on freon, recharged got temp down to 38 degrees, 3 days later all still ok and coils still clear, 1 week later top section inside and outside frozen up, charge ok but temp down to 50 degrees, is this not defrosting and where could I locate the defroster I cannot find it anywhere. Model # is 2 blade low profile


    Humm.....................I just don't know were to start with this one.
    I love the smell of phosgene first thing in the morning:

    To apply for professional membership click here


    Educational forums are open.

    If you would like to submit a link or an article or other related info to the EF. click here

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