What kind of insulation for inside of a freezer

[searching 4 paradise]

Hi,

We are considering insulating the built-in box freezer on a 42 Hunter. Considering that you have to defrost the ice build up on the plates and the moisture in there, what would you recommend using that will not mildrew. It would be great to hear from someone who has done this and was happy with it. We do not plan to permanently leave this in by means of screws or other attachments in case we have to replace it. The plan is to cut it to fit snuggly on the walls. Any thoughts/advise on this would be appreciated.

 

[Ross]

My ice box is four inches of extruded polystyrene foam with the gaps filled with canned urethane foam and the whole works sprayed with 3M adhesive and covered with very light fiberglass cloth and epoxied. It never mildews but we keep the food wiped off all the time.

 

[searching 4 paradise]

Is your ice box the same thing as a built in freezer? I read some posts about a guy wanting to know how to insulate his ice box but it sounded like he had something different from ours. It sounded like he actually kept his food cold using bagged ice cubes instead of a built-in under counter freezer with a compressor like ours. Could you clarify that for me please. Also, we were not planning on making ours permanent, just in case it doesn't work out like we planned and we may want to remove the insulation one day. Thanks.

 

[Ross]

My icebox is just that. No mechanical refrigeration system. Fifty pounds of ice in half gallon jugs will keep 34 degrees cold in the box for a week in 90 degree days. It would require a rather small mechanical system to keep the box cold all of the time.

 

[RAD]

Most boxes from boat mfg's are not insulated well so what most and I've done is to re insulate on the outside which may require taking stuff apart, on my Oday I removed the oven (why would you put this next to the ice box?) and was able to install 2 inches of rigid foam and still got the oven back in then I put 4 inch's in the area under the sink area and covered that with 1/4 plywood and did the same on the third side which was adjacent to the engine and the only area that got spray foam was the hull side and all this keeps my ice for 5 days @ 90 which is way better than when I started and if and when I get sick of hauling ice aboard and install a refrigeration system I'm ready

 

[searching 4 paradise]

We appreciate the ideas but maybe I am not explaining this right. Let me try again... We want to insulate the inside of a built-in under the counter freezer, not an ice box. It has a compressor and has a three sided cold plate near the top. It's deep and there is a fridge beside it with another compressor that is near the engine which we might also insulate if we can find out what the best material is to use for this. It is not a box where you put ice in it. We don't want to put in a new system, or insulate the outside, nor do we want to make it where we can't remove it one day if we chose to so no foam or screws, etc.

Has anyone with a Hunter with this setup ever done this kind of job and what kind of insulation did you use. Were you happy with the results. Were there any downsides to it? We are looking for an insulation that will not mildew or stay soggy from the moisture inside the units. Thanks so much.

 

[Ross]

Searching, you can get foil faced foam insulating board starting at a half inch. Cut it to fit and seal the edges with foil duct tape. Add as many layers as you wish.. What you have been told is that four inches of foam is very effective but also very demanding of interior volume. I changed the insulation on my home freezer from fiberglass to an inch and a half of foil faced foam with staggered joints about twenty years ago and haven't looked back. If you understand how insulation works you realize that air is the insulating media and the fiberglass or foam simply prevents the air from circulating the heat from the hot side to the cold side. Vacuum plates are best but cost as much per square foot as foil faced foam does per sheet. Ice has a latent heat of fusion of 143 btu's per pound. so 50 pounds of ice melting in 5 days is 10 pounds per day or 1430 btu's per day. Four inches of insulation allows a heat gain of that much in a reasonably sized ice box. For a refrigerator or freezer will be a little higher because of thinner insulation.

 

[kloudie1]

Ross is correct.. The critical thing is that the new insulation be sealed so air cannot circulate behind it.. If the edges of the stuff you add aren’t sealed with foil tape, the net gain will be very small.. A crack between the insulation pad and the old inside wall of around a sixteenth of an inch will pretty much negate any effect from the additional insulation. Good luck with it..

 

[searching 4 paradise]

I will pass this on to my better half about the foil faced insulating board and tape. Thanks. Do you have any idea where to look for something like that. Do you get it at a regular hardware store or a specialty store? I'm on the boat in Roatan so he'll have to look for it in the states and bring it down when he comes back.
Thanks again.

 

[Ross]

It is called R-Max among other names and is available in all building supply centers. I comes in thicknesses from 1/2 inch up to 2 inch and can be nicely cut with a sharp knife.

 

[searching 4 paradise]

Great. Thank you for the information. I will pass this on to the captain today.

 

[Ross]

For what it is worth. I wished to thaw a 12 pound goose for baking and got it out of the freezer and wrapped it in a winter coat and left it on a table. 36 hours later it still had frost on the package and was solid hard frozen. To hurry it up I filled the bath tub with cold water and put the goose in there in the wrapping.

 

[searching 4 paradise]

Wow, this must be really good stuff. We really do appreciate the information you've shared with us.
Take care.

 

[Steve Dion]

Have you tried insulating the lid of the box? We have doubled up the insulation around the lid on our HV'36 and it has helped considerably. I have NOT tried plugging the drain hole, but I would assume that it would also help the situation.

The insulation is inexpensive and is very easy to apply. It is the product that they use around the doors in homes and is in the shape of a "D". It has a sticky back so it is easy to apply/remove.

http://www.lowes.com/pd_127196-1410...r|p_product_model_id&ddkey=http:SearchCatalog

 

[searching 4 paradise]

Hi Steve, no, we haven't started on the project. We are just in the early stages of researching it so we don't mess up. There are a couple of other projects ahead of this one but since I'm in Roatan and it's hard to get some stuff around here. We thought we'd find out what we should use and then he can ship it to me here for when we start working on it. Thanks for the idea of doing the lids too. Our boat is like the other poster, Rad, where they put the freezer beside the oven/stove and the fridge, which is situated beside the freezer is beside the engine room. I don't think I would have designed it like that but they didn't ask me in 1994 when they built her. Thanks again.

 

[RAD]

I neglected to say that I also use a piece of rigid foam on top of the lid when its real hot and it helps a great deal, one of these days I'll insulate the lid inside
I understand what your trying to do and because of the lack of good insulation your freezer is sweating in the hot climate so while your on this mission I would try to re insulate as much as possible around both the refrigerator and freezer on the outside for the maximum energy use

 

[gettinthere]

how does r-max compare to "blueboard" foam board insulation. sounds similar

 

[Ross]

A little stronger some is made for sheathing. Won't snap if bent but will bend like corrugated cardboard. Is foil faced on both sides probably a bit better at infra red reflection.

 

[searching 4 paradise]

Ross, which one will snap if it's bent? We don't want that to happen while we are trying to work around wires and the cold plates inside.
Thanks.

 

[searching 4 paradise]

Have you tried insulating the lid of the box? We have doubled up the insulation around the lid on our HV'36 and it has helped considerably. I have NOT tried plugging the drain hole, but I would assume that it would also help the situation.

The insulation is inexpensive and is very easy to apply. It is the product that they use around the doors in homes and is in the shape of a "D". It has a sticky back so it is easy to apply/remove.

http://www.lowes.com/pd_127196-1410...r|p_product_model_id&ddkey=http:SearchCatalog

I didn't look at the link yesterday but to answer your question, yes, we have put that type of stripping around all the doors and lids on both the freezer and the fridge.
Thanks.