Excessive condensation from Refrigerator

[Ardens2]

We have a 1999 boat and upgraded the fridge/freezer to Frigiboat with a keel cooler 2 years ago. Up until now we have used the boat for weekends and the annual 2 week vacation in the Bahamas. We have moved onto the boat about 2 months ago and headed up to the northeast for hurricane season. Our plans are to head to the Caribbean, panama canal, South Pacific and New Zealand but those plans are up in the air.

We are having excessive condensation on all sides of the refrigerator/freezer. We did have a refrigerator company in Fort Lauderdale install some insulation in 2019. Now with this condensation we have reinsulated ourselves (inside and outside freezer) with new insulation including aerogel insulation. Even immediately after defrosting the freezer the condensation is out of control. It is much worse on the humid days.

We are talking with a marine repair about our options;
1. vacuum panels (though we hear there is a long wait time
2. rebuilding the whole fridge area with 6 inches of insulation on each side which is a considerable loss of space
3. a ready made unit like the Vitrifrigo freezer refrigerator drawers (DW180IXD4-EF) and have the area customized around that?
Any suggestion to help with the condensation before we end up with wood rot? Anyone with experience with the Vitrifrigo unit?

[ttex]

Sounds like you have a bad seal.

[Coolerking]

Insulation is not effective unless you have a true vapor barrier.

[Ardens2]

Aerogel is coated with plastic sealing on both sides and the foam insulation is coated with aluminum on both sides. Do you consider this sufficient for a vapor barrier.

[s/v Jedi]

Your problem is the seal with the opening lid or door. Or you open it too much. Moist air is entering the box.

[skipgundlach]

We redid our space to use 6" of extruded polystyrene (Dow/Other-unremembered-now) in 2" and 4" ladderstepped, epoxy coated before hand, and the like.

The condensation on our freezer lid isn't as bad as yours but likely that's a product of how much insulation we have. Our handle is like yours, and it, too, sweats in the horrible humidity of Vero Beach summers.

We used an inexpensive, but very effective (soft, giving, irregularity-accommodating) "C" gaskets on our doors, both surface and interior (double gasketing).

It's easy enough to work with that if needed, we pull the door, cut out any damaged segment, and splice it in with superglue, and reinstall; it's held down by the furnished double-sided sticky (peel off the paper) which, under pressure (doors closed) lasts a very long time.

This one came from Home Depot; I imagine others carry it:

Pictures: Flying Pig 2013-2014 Shakedown/Refrigerator Gaskets

[jamhass]

Cut a yoga mat to fit as one piece over the top of the refer/freezer. If this cuts down on the condensation, you definitely have a seal leak. Leave the mat in place to add insulation, reduce leaks and provide a non-skid surface to the counter.

[Richard Kollmann]

Condensation inside the box is caused by air infiltration into inside of box each time compressor runs, if lid or door seal can not maintain slight air pressure changes inside box.

Condensation on outside of box indicates insulation has failed and is conducting excessive heat to box's exterior surface. If exterior of insulation is with in 8 degrees of surrounding ambient air temperature, exterior condensation is possible. Four Degrees is exceptionable perfect insulation would be zero temperature differential. The reason your present insulation failed is it is open cell insulation and becomes a dehumidifier collecting moisture if air can enter it and exit each time compressor cycles leaving moisture inside.

[Mike Banks]

A bad seal will always drop the ball.

[Montanan]

Attachment 219589

Originally Posted by Ardens2

We are having excessive condensation on all sides of the refrigerator/freezer.
We did have a refrigerator company in Fort Lauderdale install some insulation in 2019. Now with this condensation we have reinsulated ourselves (inside and outside freezer) with new insulation including aerogel insulation. Even immediately after defrosting the freezer the condensation is out of control. It is much worse on the humid days.

We are talking with a marine repair about our options;
1. vacuum panels (though we hear there is a long wait time
2. rebuilding the whole fridge area with 6 inches of insulation on each side which is a considerable loss of space
3. a ready made unit like the Vitrifrigo freezer refrigerator drawers (DW180IXD4-EF) and have the area customized around that?
Any suggestion to help with the condensation before we end up with wood rot? Anyone with experience with the Vitrifrigo unit?

Where is the excess condensation occurring, inside or outside of the refrigerator, or both?

What are the temperatures of the outer surfaces of your cabinet? Measure with an infrared thermometer where the moisture is apparently forming, if there is active water condensing then the temperature of that surface will read below the dew point for the relative humidity of the ambient air. You will need to improve the insulation to mitigate such occurring.

If you are having a lot of frosting inside then you are either opening the refrigerator frequently thereby allowing large loads of humid air inside the chiily box which humidity will dew out on the cold surfaces, and / or freeze on the below freezing surfaces; or you have leaking seals that allow for continuous infiltration of moist air and also escape of the drier cold air that should remain inside the box. Resolution is to access the fridge less frequently and / or fix leaking seals.

If you are having condensation on the outside then your insulation is likely inadequate or you have not sealed the insulations such that humid air is infiltrating the insulation and making contact with a cold surface, or both. Was the insulation firmly bonded to the outside of the refrigerator / freezer so that there is no potential for an air layer which air could be being exchanged and thus allowing for continuous humidity / water vapor to make contact with the comparatively cold surfaces. Insulation should be glue contacted completely.

The physics is really straight forward, water vapor will phase change to liquid when it touches a surface that is colder than the dew point applicable to the relative humidity of the air at the moment of contacting the cold surface, or if the air cools and the relative humidity rises to above saturation point, i.e., it rains, or freezes.

Yes the problem worsens when the relative humidity increases as the dew point is achieved at ever higher temperatures with increasing relative humidity. There is no fixing that which is controlled by nature.

You could pursue dehumidifying the air inside your boat so as to have the dew point temperature rise relative to the lowered relative humidity.

Reference the relative humidity dew point chart below.

[Ardens2]

Agree, the door seals are contributing to condensation but condensation is also occurring on an adjoining wall. Agree with Richard that it is failure of the present insulation. Thanks for all your replies. At this point we are looking at a rebuild with increased insulation and improved door seals or vacuum panels or a pre made unit like Vitrifrigo. Any thoughts?

[Coolerking]

Heater wires are used occasionally to keep the condensation at bay.
We also use a physical thermal break to keep our custom stainless steel boxes from condensating moisture on the exterior surface.

[Grattaway]

I am assuming you are talking about the exterior of the box

You should not need 6 inches of insulating material if you are going to replace- think of a house fridge/freezer and how thin their walls are. The insulation material is nearly always a form of polyurethane not polystyrene as the former has better insulating properties - but important to seal well so that moisture cannot enter the insulation itself.

But faulty seals can also allow cold to escape - which can cause condensation on an adjacent wall as the cold air escaping will sit in the bottom of a cavity being heavier than the outside warmer air. It can also cool some of the warmer outside high humidity air thereby creating a condensation layer

Good Luck

[Coolerking]

It's the heat going in that causes the condensate, there is no such thing as cold...only heat, or lack of it.
It's where the exchange takes place that causes it.
That's why we use physical thermal breaks and true vapor barriers to prevent it from making the transition from the inside of the refrigerated space and the exterior.
We also use custom Getters panels on the high end stuff.
After all there is no better insulation than a vacuum.
Start with the gaskets and the door latches and hinges.

[MikeTC]

Our insulation was not sealed from the atmosphere and became saturated from condensation and ineffective. We replaced the fridge with totally sealed insulation. No more condensation and way more efficient. Hope you get it sorted.