Should I redo the insulation of my 35 year old built in fridge? With what?

[rotorman]

I am replacing my refrigeration system.

The fridge is built into the kitchen cabinet and 35 year sold.

Should I also replace the insulation (big job).

What material should I use for insulation? Can I just fill the gap between the cabinet wall and fridge wall with polyurethane foam (from a CAN)?

Regards
Geza

[Reefmagnet]

My wife just redid our fridge in a near identical scenario. She used an aerosol can (or two) of spray foam and bean bag balls packed down as hard as she could manage. She gained access via a number of pre-existing external holes but finished off by drilling holes in the interior liner of the fridge itself. When done, she filled the holes with thickened epoxy and painted the interior liner with white epoxy paint and the exterior with a paint matching the original gelcoat in colour.

One tip I can suggest is to use a laser contact-less thermometer to map the external temperature of the fridge. This will reveal the cold spots that indicate where insulation is lacking. We monitored these locations as the job progressed to ensure that the insulation was improved at these points. One annoying aspect of our fridge was that it had an area of no insulation where it extends under a cupboard. I guess the purpose of this was to create a cooler area for stuff. We intend to line this cupboard with Styrofoam insulation panels as we don't require this "feature".

At the end of the day I don't think this repair would be as good as tearing everything apart and replacing the insulation with the "proper" stuff, but with the alternative being to have to perform some fairly major surgery, I think it was the best compromise.

[Reefmagnet]

Double post

[Typhoon]

Redoing your ice box insulation really is different for everyone . It always depends on your long term goals . Are you a weekend sailor or a live aboard sailor in the tropics. Also depends on your boat. You don't spend 20000$ dollars on a 1000 dollar boat . Also the other side of that coin is you want to protect the value of your boat if it was a substantial investment .

Regards John

[skipmac]

I think John summarized it pretty well although if he's talking about $20,000 on a fridge his systems must cost a lot more than I thought.

Seriously, I plan extensive cruising so I did a total rebuild of my fridge which involved cutting out the old box, taking apart the cabinet that housed the fridge, all new insulation, redoing the old box to a smaller size and reassembling the whole thing. Turned out to be by far the most time consuming project of my entire refit which was pretty extensive. However I now have a 9-10 cu ft box which holds a 1.5-2 cu ft freezer that uses about 40-45 amp hours a day in mid summer.

If you really want to do it right and plan to use the fridge a lot this is the way to go. If occasional and weekends then maybe a less extensive rebuild would suffice.

There are more efficient insulation options but I chose to use Dow blueboard (polystyrene) for ease of use and easy availability. I also felt like it offered the best long term resistance to moisture absorption.

If you decide to go for it I can offer a few suggestions on how I did it and what I would do differently if I had to do it over again.

[rotorman]

Thanks all.

To clarify my question, I was wondering if the original insulation has broken down in the 35 years.

I am living aboard full time mainly in the tropics.

I would do the job myself have done similar things. I was thinking of cutting out the old box and redoing the insulation and internals.

[robert sailor]

If your planning a full time cruising lifestyle then yes do whatever you can afford to insulate and seal your fridge. It is the biggest amp hog on the boat and the money that follows for solar panels, wind generators,high output alternator and large battery banks are mostly about the bloody fridge.
If your a weekender and your boat gets a regular diet of shore power then it's probably not worth the effort nor will you get the payback.

[Typhoon]

Originally Posted by skipmac

I think John summarized it pretty well although if he's talking about $20,000 on a fridge his systems must cost a lot more than I thought.



Seriously, I plan extensive cruising so I did a total rebuild of my fridge which involved cutting out the old box, taking apart the cabinet that housed the fridge, all new insulation, redoing the old box to a smaller size and reassembling the whole thing. Turned out to be by far the most time consuming project of my entire refit which was pretty extensive. However I now have a 9-10 cu ft box which holds a 1.5-2 cu ft freezer that uses about 40-45 amp hours a day in mid summer.



If you really want to do it right and plan to use the fridge a lot this is the way to go. If occasional and weekends then maybe a less extensive rebuild would suffice.



There are more efficient insulation options but I chose to use Dow blueboard (polystyrene) for ease of use and easy availability. I also felt like it offered the best long term resistance to moisture absorption.



If you decide to go for it I can offer a few suggestions on how I did it and what I would do differently if I had to do it over again.

Yes, I was just making a point . But I have seen people spend that kind of money and more when refitting a galley .

Regards John

[skipmac]

Originally Posted by rotorman

Thanks all.

To clarify my question, I was wondering if the original insulation has broken down in the 35 years.

I am living aboard full time mainly in the tropics.

I would do the job myself have done similar things. I was thinking of cutting out the old box and redoing the insulation and internals.

Whether the old insulation has broken down will depend to a large extent on what Amel used in the original construction. Amel does build good boats that are made for cruising so it is quite possible they used good, long-term stable insulation and enough of it.

Unless you make some holes or can access the back of the fridge the only thing to do is check by amp hour usage or test how long the box will hold temp without running the compressor.

[skipmac]

Originally Posted by ColdEh Marine

Yes, I was just making a point . But I have seen people spend that kind of money and more when refitting a galley .

Regards John

I got that, just couldn't resist a small joke. I do know one can spend that much on a galley rebuild, just not on my boat.

[Typhoon]

Originally Posted by robert sailor

If your planning a full time cruising lifestyle then yes do whatever you can afford to insulate and seal your fridge. It is the biggest amp hog on the boat and the money that follows for solar panels, wind generators,high output alternator and large battery banks are mostly about the bloody fridge.
If your a weekender and your boat gets a regular diet of shore power then it's probably not worth the effort nor will you get the payback.

I Agree !

Remember 90% of the time your boat is your house , and when you are at anchor for weeks on end , the only thing that is eating your energy reserves will be your refrigeration. If this is the kind of cruising that is ahead of you , do the job right , it will pay ten fold in the end .

Regards John.

[skipgundlach]

Insulation life...

Insulation quantity...

Insulation quality...

Both are currently unknowns. But the typical production boat has not much of either of the latter 2, and the nature of the first depends on the makeup.

All foams (and vacuum panels) lose efficiency over time. There's probably a source to define the useful life of each, though I believe, when we did ours, we were told 'about 15 years' before significant decline in R value.

We, too, cut out our prior, very inadequate, insulation, tub and cabinetry and started over. We used 2 and 4 inch 4x8 blocks of extruded polystyrene (blue or pink board doesn't matter), and encased it in epoxy as it went in, stairstepping the joints to minimize any potential heat travels.

Our first system, a Frigoboat, worked a treat other than (now fixed, I understand) a design issue which eventually caused an immobile clog in our evaporator. Due to the way we'd built it, I was unable to do anything other than a destructive removal of the evaporator plate, and was forced to go to a different solution.

Unless my insulation suffered a catastrophic change in R value in the months we worked to try to solve this issue, however, I've concluded that I'd have been better off to have destroyed the countertop and redone the freezer segment (which I'd have to have destroyed the top of), going back with the original.

As small as your space is, I suspect that you don't have the luxury I did of taking out a 19CF tub and fabricating a 3.5/7CF freezer/reefer, the difference nearly entirely a matter of the volume of insulation. In that case, vacuum panels, with the system designed for later disassembly without destruction, might be your answer...

As to design, indeed, make your gasketing as effective as you possibly can; ours has double (6" apart, as that's the thickness of the insulation) gaskets, on the door and the box faces...

[mikecambrai]

Insulation of a fridge is one of the keys to reducing your power consumption and for ensuring that there is enough ice for the G&T's at 1800 hours.
I am always careful about fire risks so have always used Rockwool fibres. DOn't know whether you can get that in the States. Air is the insulant, and putting slabs of styrene is OK as long as you seal the edges with duct tape to create a seal between the fridge and the insulant. Make sure that the styrene is flame retardant!
Buble wrap would be a good cheap alternative. The object is to trap the air into lots of sealed pockets.
The other factor to consider is to make the fridge as efficient as you can by making sure that the condenser at the back is in a good airflow to take away its heat. I always mount a computer fan adjacent to my fridge motors on all my boats in the past as I have found that in hot weather the fridge efficiency drops off rapidly and there is no ice for the management.

[john61ct]

Put an AH-counter (~$30) on the fridge circuit when it is full and temps set the coldest you ever do.

Report back the 24-hour consumption, average ambient and cubic volume.

[bjymd]

The insulation is key to efficiency. I would add that making sure that the exhaust flow is clear and adequate is also important to allow peak efficiency from the unit. Some units do not exhaust into the cabin directly but go thru the cabinetry before exiting. Make sure the holes ( a screen is better) into the cabin allow adequate exhaust. Good luck.