Freezer defrost problems
Page 1 of 2 12 LastLast
Results 1 to 13 of 20
  1. #1
    Join Date
    Feb 2005
    Posts
    1
    We have a 10 x 22 walk-in freezer with an icing up issue. If we leave the unit in defrost long enough to fully clear the coil, then there is a major condensation build up on the ceiling. Electric defrost. Any ideas?

  2. #2
    Join Date
    Jan 2005
    Location
    Veterans Home Yaphank, NY
    Posts
    2,309

    Hmm Re: Defrost

    Check the fan delay. When they go bad the unit does not get rid of the water in the drain pan, and the fans come on and blow that water all over the place
    RAM Teaching Tomorrows Technicians Today.

  3. #3
    Join Date
    Oct 2001
    Location
    KC MO
    Posts
    37
    How many defrosts are you running and for how long? Does this unit have a defrost termination switch ? and is it working ? Is the box tight?

  4. #4
    Join Date
    Feb 2004
    Location
    northern colorado
    Posts
    90

    steamy

    You may wan t to check the drain line, make sure it's working correctly. Check the drain heater, check for restrictions, slope. Also check the evap pan for drainage.

  5. #5
    Join Date
    Feb 2004
    Location
    Medford Oregon
    Posts
    807
    you have got seapage, your insulation is probably
    broken down, you can fiddle around with timers, etc
    but that will be of no value. if your ceiling is
    producing ice, you need to reinsulate

  6. #6
    Join Date
    Dec 2004
    Posts
    56
    it sounds like your fans are coming on too early i iagree with icehouse look at your fan delay control if you got frozen water droplets on your ceiling thats a sighn of your fans coming on too soon. also how long of a drip time do you have?

  7. #7
    Join Date
    Feb 2003
    Posts
    1,166
    1 possibility is the drain line, it needs to be trapped to prevent infiltration of warm air at coil.
    Watts New, Ohm My, I been Electrically Commutated. Are U2.

  8. #8
    Join Date
    Jun 2001
    Location
    San Diego, CA
    Posts
    1,149
    also a sign of a coil in defrost too long. vapor rolling out the front of the coil condensing on the box lid.

  9. #9
    Join Date
    Feb 2005
    Posts
    4

    Smile

    all of the above have some merrit.
    but it sounds like the unit could be building up too much frost at one time. cheak the temp setting ,be sure it has some off cycle time.
    we dont know how many defrost you have. you my need to add one or two more defrost times set at 35-40 min.the unit should not take that long, the defrost terminator should drop it out before the timer. the timer is a back up. CHEAK YOUR SUPERHEAT TO PRODUCE A GOOD EVEN FROST PATTERN.

    [Edited by icetec9 on 02-08-2005 at 05:10 PM]

  10. #10
    Join Date
    Aug 2004
    Location
    S.E. North Carolina Coast
    Posts
    124
    I concur with mccool. Drain line should be trapped.

    What about the door? Does it close easily?
    Strip curtains?
    Door closer?
    Do your customers tie the door open for long periods of time?
    If you limit the moisture infiltration you will minimize the frost.

    Please check the fan delay defrost termination switch.
    Advise at least 4 defrosts per 24 hours @ 45 minutes if FD/DT switch is working properly.

    What is the room thermostat set for? -10 degrees is advised unless your customers have ice cream being stored.
    The colder the box the more frost will appear.

  11. #11
    get a new coolroom

  12. #12
    Join Date
    Jan 2005
    Location
    Veterans Home Yaphank, NY
    Posts
    2,309

    Talking Re : Freezer Defrost Problem

    One other thing I forgot to ask is where is the blower located, it should be on the wall opposite the door opning. I had a similar situation at the Sheraton Hotel in Manhattan, and sure enough the blower was mounted on the side wall as soon as you opened the door. This lets in warm humid air, even with a curtain which will condense on the ceieling and being a freezer this condensation froze. They had already had a company come in and sell them reinsulation andnew diamond plate. Guess what ? they still had the same problem because of the blower location. After moving the blower opposite the door, no more problems.
    RAM Teaching Tomorrows Technicians Today.

  13. #13
    i had a simular problem with a -20 walk-in, defrosting the coils 4 time a day, it would still take over an hour to clear the coil. the heater wattage seem to be low, impart due to low voltage. but after talking to the field tech for the manifacture, he explained to me that these evaporators were design with lower wattage heater to save energy, go figure !!! They did have a retro fit kit that doubled the defrost heater wattage. After the retro the defrost times were less than 30 minutes.

    Because of the slow defrost i also had water droplets on the ceiling. Check your voltage to the heaters, my original heaters were rated at 1000 watts @ 230 volts, i only had 197 volts, thats about 15% less capacity, that makes a big differants. Your defrost cycle must terminate on temperature, NOT ON THE TIMER, make sure this is happening. to do this check your evaporator fans just after defrost, they should NOT be operating. There must be a fan delay.

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event