Ice on Cold Plates - Good or Bad ?

[Full Sail]

I live on my boat and have carefully cultivated(?) a block of ice about 10 inches thick on the coldplate in my icebox. Someone suggested that I defrost it because it is making my refrigeration work harder. I've noticed that with the ice, my icebox stays at a fairly consistant temperature. Any theories out there? Thanks

[GordMay]

Bad.
With 10" of frost, you don't have a refrigerator, you have an ice-box.
The holding plate should get much colder than 32 deg. F, so ice/frost build-up is actually an insulator.
The holding plate should be “slowly” defrosted when the frost gets to about 1/4" → ½" thick.
Defrosting must occur slowly enough to prevent rapid thermal expansion of the metal and refrigerant. Warm water or an open lid and fan are safest.
Never use a scraper on “thin plate” evapourators.
Since environmental moisture is the cause of frost build up on the holding plate, make sure that the gasketing on the lid is sealing tightly.

[senormechanico]

Gord's right.
On our previous boat which had a cold plate, to defrost, we used our inverter and a heat gun.
Worked great. We were done in just a couple of minutes.

[cfarrar]

Come to think of it, my practice of keeping ice in the ice trays against the cold plate is probably not efficient. Once the ice cubes are formed I should move them to the bottom of the box and then allow the cold plate to be exposed to the air.

We defrost with with a quick spray of room temperature water from a spray bottle. Takes about 1 minute if you do it before the frost gets too thick.

[Pete7]

We find a couple of bar top beer mats in the bottom of the fridge and changed every couple of days keeps the build up of condensation down to a minimum.

Pete

[GordMay]

Originally Posted by Pete7

We find a couple of bar top beer mats in the bottom of the fridge and changed every couple of days keeps the build up of condensation down to a minimum.
Pete

What are "beer mats"?

[Full Sail]

Thanks for your replies, There was an iceberg floating down the New River in Ft Lauderdale today.

[daddle]

Originally Posted by GordMay

Bad.
With 10" of frost, you don't have a refrigerator, you have an ice-box.
The holding plate should get much colder than 32 deg. F, so ice/frost build-up is actually an insulator.

You might be right. Or not. But that statement makes no thermodynamic sense. If the fridge is the temp he desires there can be no problem. No loss of efficiency. Nada. The holding plate will be whatever temperature it needs to be to keep the box at that temp.
The ice next to the coldplate can easily drop to whatever temp. Nothing wrong with an icebox.

The loss of storage space might be a problem, however.

[Full Sail]

LOL, yeah it did take up about half the box. I am monitoring how much and often the compressor runs now that there is no ice

[nhschneider]

The guy who installed my refrigeration system says that ice build-up on the holding plate is indicative of air getting into the refrigerated space. When the ice on my holding plates built up, Captain Frost had me put a dollar bill on the weather stripping, close the door and then try to remove the bill. He says that the weather stripping should grip the bill well. If it doesn't, the weather stripping isn't sealing properly. Perhaps I didn't explain that too well but maybe you get the idea.

Fair winds and calm seas.

[bstreep]

If the buildup is ICE, rather than FROST (with air in it), it shouldn't be a big deal - the ice should be nearly the same temperature as the holding plate. HOWEVER, most of the time I've seen buildup it's FROST - which has a lot of air in it, and therefore insulates.

We have a 110 volt system for the fridge and freezer (separate), and on weekends we turn the system off, which keeps the holding plates frost/ice free.

[four winds]

beer mat's?

After a couple o' brews, are sporting paraphernalia, apparently.

The Official Beer Mat Flipping Website

Sometimes a normal Google search is better, Gord.