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13-02-2020, 14:06
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#16
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Marine Service Provider
Join Date: Aug 2004
Location: Ft. Lauderdale
Posts: 1,885
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Re: Freezer Frosting Up Too Fast
No need to have excessive frost in modern boat refrigeration boxes.
Frost build up inside refrigerator or freezer results from two sources air moving in and out of box and moisture absorbed from product inside box. Refrigerator and icebox design engineers prior to 1960 used door latches that mechanically applied over center excessive pressure latches to compress door seals. Next generation of refrigerator door seals to keep moist air out was the magnetic seal. Even with comprisable door seals temperatures and pressures inside refrigerated boxes continually change increasing air movement in and out of boxes. Refrigeration electrically controlled thermostats are all designed to allow for a rest period between stop and start cycles to normalize compressor temperatures and normalize box temperatures. Variation in box temperature results in an air pressure differential from box interior and external air pressure allowing air movement through a less than efficient door seals even when lid or door is kept closed for 24 hours. The answer today for interior frosting in small refrigerator/ freezers is by limiting varying box temperature that causes positive and negative pressure changes inside boxes. The design solution now to prevent frost formation is a thermostat that controls evaporator temperatures and not box temperatures. Conventional 3 to 8 cu ft boat refrigeration systems will have a thermostat sensing temperature of a properly sized standard evaporator and not box temperature. On these thermostats set at mid range evaporator temperature is designed to be +12 F with a OFF ON differential of plus or minis of seven degrees differential desired box temperature rarely varying more than plus or minis 2 degrees F.
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13-02-2020, 14:24
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#17
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Registered User
Join Date: May 2008
Location: puɐןsuǝǝnb 'ʎɐʞɔɐɯ
Boat: Nantucket Island 33
Posts: 4,864
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Re: Freezer Frosting Up Too Fast
Low refrigerant pressure can cause icing. Is the unit cycling correctly?
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13-02-2020, 14:28
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#18
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CLOD
Join Date: Jul 2007
Location: being planted in Jacksonville Fl
Boat: none
Posts: 20,426
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Re: Freezer Frosting Up Too Fast
Quote:
Originally Posted by Richard Kollmann
No need to have excessive frost in modern boat refrigeration boxes.
Frost build up inside refrigerator or freezer results from two sources air moving in and out of box and moisture absorbed from product inside box. Refrigerator and icebox design engineers prior to 1960 used door latches that mechanically applied over center excessive pressure latches to compress door seals. Next generation of refrigerator door seals to keep moist air out was the magnetic seal. Even with comprisable door seals temperatures and pressures inside refrigerated boxes continually change increasing air movement in and out of boxes. Refrigeration electrically controlled thermostats are all designed to allow for a rest period between stop and start cycles to normalize compressor temperatures and normalize box temperatures. Variation in box temperature results in an air pressure differential from box interior and external air pressure allowing air movement through a less than efficient door seals even when lid or door is kept closed for 24 hours. The answer today for interior frosting in small refrigerator/ freezers is by limiting varying box temperature that causes positive and negative pressure changes inside boxes. The design solution now to prevent frost formation is a thermostat that controls evaporator temperatures and not box temperatures. Conventional 3 to 8 cu ft boat refrigeration systems will have a thermostat sensing temperature of a properly sized standard evaporator and not box temperature. On these thermostats set at mid range evaporator temperature is designed to be +12 F with a OFF ON differential of plus or minis of seven degrees differential desired box temperature rarely varying more than plus or minis 2 degrees F.
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Not sure what I am suppose to do with that info.
My freezer measures the evaporator temp, not the air.
I have it on the coldest setting. Ate you saying turn it down?
__________________
Don't ask a bunch of unknown forum people if it is OK to do something on YOUR boat. It is your boat, do what you want!
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13-02-2020, 14:45
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#19
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Registered User
Join Date: Jan 2016
Location: Beaufort, NC, USA
Boat: Ta Chiao 56
Posts: 753
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Re: Freezer Frosting Up Too Fast
Quote:
Originally Posted by sailorboy1
Not sure what I am suppose to do with that info.
My freezer measures the evaporator temp, not the air.
I have it on the coldest setting. Ate you saying turn it down?
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If it's on the coldest setting, you can't turn it down, you'd have to turn it up, in other words increase the temperature setpoint.
As Reefmagnet asked, is it cycling normally?
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13-02-2020, 14:51
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#20
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Registered User
Join Date: Jan 2020
Posts: 241
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Re: Freezer Frosting Up Too Fast
I'm sure you have checked but is the door/lid actually closing fully? I've had obstacles and misaligned hinges prevent full locking and therefore moisture entering non stop.
Also, aftermarket magnetic rubber seals can be much less forceful than OEM. How difficult is it to open the door/lid if you do have magnetic seals?
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13-02-2020, 15:01
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#21
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CLOD
Join Date: Jul 2007
Location: being planted in Jacksonville Fl
Boat: none
Posts: 20,426
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Re: Freezer Frosting Up Too Fast
I took the latches off my box lids years ago because i got tired of them hanging up.
__________________
Don't ask a bunch of unknown forum people if it is OK to do something on YOUR boat. It is your boat, do what you want!
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13-02-2020, 15:05
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#22
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Registered User
Join Date: Oct 2010
Location: The boat - New Bern, NC, USA; Us - Kingsport, TN, USA
Boat: 1988 Pacific Seacraft 34
Posts: 1,455
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Re: Freezer Frosting Up Too Fast
When you are looking for sources of water for your frost don't forget water evaporating from the ice trays and condensing on the cold plates. A nice thing about the vertical trays is that they have a small exposed water (ice) surface area. There are also horizontal ice trays with covers.
Bill
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13-02-2020, 15:10
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#23
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Marine Service Provider
Join Date: Aug 2004
Location: Ft. Lauderdale
Posts: 1,885
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Re: Freezer Frosting Up Too Fast
Quote:
Originally Posted by sailorboy1
Not sure what I am suppose to do with that info.
My freezer measures the evaporator temp, not the air.
I have it on the coldest setting. Ate you saying turn it down?
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If you need to defrost refrigerator or freezer more often than three weeks or if box temperature is operating with fluctuation of more than few degrees take measures to prevent most air infiltration into box. If you have eutectic plate evaporator or thermostat is controlled by box temperature narrow down thermostats differential setting.
Turning thermostat to a warmer setting will daily reduce energy but is not a good solution unless you are able to maintain your desired box temperatures. Sometimes putting a plug in box drain will help prevent air infiltration at weak door or lid seals.
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13-02-2020, 15:11
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#24
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CLOD
Join Date: Jul 2007
Location: being planted in Jacksonville Fl
Boat: none
Posts: 20,426
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Re: Freezer Frosting Up Too Fast
Dont have any ice trays in my freezer. I long ago learned that the water just moved from the trays to the evaporator.
__________________
Don't ask a bunch of unknown forum people if it is OK to do something on YOUR boat. It is your boat, do what you want!
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13-02-2020, 15:14
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#25
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CLOD
Join Date: Jul 2007
Location: being planted in Jacksonville Fl
Boat: none
Posts: 20,426
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Re: Freezer Frosting Up Too Fast
Quote:
Originally Posted by Richard Kollmann
If you need to defrost refrigerator or freezer more often than three weeks or if box temperature is operating with fluctuation of more than few degrees take measures to prevent most air infiltration into box. If you have eutectic plate evaporator or thermostat is controlled by box temperature narrow down thermostats differential setting.
Turning thermostat to a warmer setting will daily reduce energy but is not a good solution unless you are able to maintain your desired box temperatures. Sometimes putting a plug in box drain will help prevent air infiltration at weak door or lid seals.
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You know Richard, i understand you have lots of experience. But i don't think you read what i have already written.
__________________
Don't ask a bunch of unknown forum people if it is OK to do something on YOUR boat. It is your boat, do what you want!
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13-02-2020, 16:48
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#26
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Registered User
Join Date: Jan 2008
Location: SF Bay Area (Boat Sold)
Boat: Former owner of a Valiant V40
Posts: 1,172
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Re: Freezer Frosting Up Too Fast
Quote:
Originally Posted by sailing_gal
I keep an insulated cover over the freezer section of my fridge/freezer so if I only need to access the fridge, the freezer isn't so exposed to the air. I just cut one to fit from insulating aluminum sided bubblewrap.
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What she said, but I use a cut-down yoga mat. Also makes a nice non-slip surface on the refer/freezer.
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13-02-2020, 16:52
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#27
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CLOD
Join Date: Jul 2007
Location: being planted in Jacksonville Fl
Boat: none
Posts: 20,426
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Re: Freezer Frosting Up Too Fast
Quote:
Originally Posted by Pete7
Pop a torch in it at night time and turn all the other boat lights off. Can you see any light coming out?
Pete
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No lght seen on any of the door or lid seals.
__________________
Don't ask a bunch of unknown forum people if it is OK to do something on YOUR boat. It is your boat, do what you want!
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13-02-2020, 16:54
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#28
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CLOD
Join Date: Jul 2007
Location: being planted in Jacksonville Fl
Boat: none
Posts: 20,426
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Re: Freezer Frosting Up Too Fast
I defrosted yesterday and will need to tomorrow.
__________________
Don't ask a bunch of unknown forum people if it is OK to do something on YOUR boat. It is your boat, do what you want!
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13-02-2020, 17:12
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#29
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Registered User
Join Date: Oct 2010
Location: The boat - New Bern, NC, USA; Us - Kingsport, TN, USA
Boat: 1988 Pacific Seacraft 34
Posts: 1,455
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Re: Freezer Frosting Up Too Fast
Quote:
Originally Posted by sailorboy1
No lght seen on any of the door or lid seals.
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What about the puttied up holes where the freon tubing comes into the box?
In addition to light, there is also the $20 test for the lid seals. Close the lid on a $20 bill, and try to pull it out. (There is also the lower cost version which is just as effective.)
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13-02-2020, 18:51
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#30
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Registered User
Join Date: Oct 2015
Posts: 2,007
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Re: Freezer Frosting Up Too Fast
Sailorboy,
I know you are sure that you have eliminated this, but the only way THAT much water can be getting into your bow is if you have large open trays of how water in there (which you do not) or if you have a significant air leak. We can't find it for you....
The traditional way to tell if your seal is leaking is to close it on a piece of paper. If the piece of paper pulls out easily, it is not tight enough. (Since it is a boat you should use a $100 bill...)
Back up the thread you say you removed the latch that holds the lid down... With the proviso that I have no idea what you lid looks like, that would concern me...
Pictures will help us diagnose the problem...
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