Walk-in Fridge AC Freeze Up - HELP

[nealperkins]

I've posted on this problem before; but, now that the humidity is up, this is really bad.

Every time I am in the fridge for more than 15 seconds, the AC will freeze up and hang. Not acceptable.

I have a small fan hanging in front of the evaporator. I think it works...a little.

This new, 5500 BTU unit is controlled by a Ranco and I have it set at 38 - with a 5 degree differential. (I wish I had wired up the AC so that the fan runs continuously...now that would be a chore.)

I've got to fix this. I am willing to buy a different AC if there is a better (more appropriate) one.

HELP!

 

[chrislehr]

The walk in fridge thread had to use several small computer fans blowing over the coils..

https://www.homebrewtalk.com/f51/my-latest-project-walk-cooler-11440/

 

[nealperkins]

Right - that is what is not working.

 

[wildwest450]

Is it by chance a Frigidaire ac?


.

 

[samc]

I completely covered the front of my ac with a 1" thick piece of open cell foam, in addition to a bucket of damp rid on the floor, I'm also blowing air through the foam with a fan. Major improvement in operation and the freeze ups went away.

 

[nealperkins]

It is not a Frigidaire. It is a new 'cheapy' from Lowes.

That is interesting about the open cell foam, I wonder why that works??

I can try the Damp Rid but, the moisture is really quick to condense on the cold kegs and then the freeze up happens in 30-45 minutes. So, I'm not sure there would be enough time for the Damp Rid to work.

I am wondering about a plastic Air Curtain to limit the cold/warm air transfer?

 

[kladue]

You need the dual sensor Ranco or Love TSS2 temperature switch, one sensor for ambient, other for coil surface temp. The coil sensor shuts the compressor down while fan is running on a call for cooling to defrost the evaporator coil on the fly. The "cheap" Ac unit run such small evaporator coils that they run well below freezing temps, when used in the cold rooms will ice up quickly. Not much can be done for window air conditioner cooling units, just try and absorb the ambient moisture with dehumidifier chemicals, and seal all the air transfer openings.

 

[leboeuf]

How big is the area you're trying to cool?

Do you have a good vapor barrier? This sounds like your getting a lot of moist air leaking in. If your area is not large, the ac unit should condense all the moisture in the airspace fairly easily. If you have a constant flow of moist air coming in, there will be nothing you can do to get the thing working well.

 

[nealperkins]

There are no (zero) air leaks except the door.

The size is 4 x 8 x 7.5.

It only freezes up when I access the door for more than about 20 seconds. And then being careful the close the door behind me.

I'm thinking I need the air curtain.

 

[freefallnick]

I worked at a black angus restaurant a while back and both of their walk ins had the plastic curtains. I could stand in the walk in with the door open and not feel any warm air coming in. I'd say anyone with a walkin should have them...

 

[samc]

That is interesting about the open cell foam, I wonder why that works??

I think it is wicking moisture out of the air and warming the air at the same time.

It's a very cheap thing to test, although I have no idea where I got the foam. Must have been packing for electronic equipment that I bought.