What's the best modern freezer unit?

[Jolly Roger]

I want to convert my existing ice box into a full freezer. I have read most of the manufacturers blurbs, but would value any input from actual users.
I'm sure this question has been asked before, but there have been some recent innovations.

Here are spec’s I think are relevant:
The existing box has about 3” of good foam all the way round.
It has a 12” square insulated top opening.
The capacity is 4.5 cu ft with room for a flat evaporator on any of three sides.
The machinery can be mounted next to the box.
I have a 6.5Kw generator, a wind genny, and will fit solar panels before we go cruising.
I favor a 12 volt, water cooled unit, but I wonder if anyone makes a 120/12 volt unit?
I don't want to have to change a sea cock, as in the case of the Isotherm water cooled condenser.
Thanks in advance.

[a64pilot]

Just curious, why do you favor water cooled? I can only think of disadvantages, but then I want to be in the tropics all the time.
I think maybe a 120/12 V unit is really just a 12V with an inverter, so any 12V can become a 120V real easy if that is true

[Jolly Roger]

Originally Posted by a64pilot

Just curious, why do you favor water cooled? I can only think of disadvantages, but then I want to be in the tropics all the time.
I think maybe a 120/12 V unit is really just a 12V with an inverter, so any 12V can become a 120V real easy if that is true

It’s only that I was told a water cooled unit is more efficient, and I didn’t particularly want warm air blown into the saloon, where I’m trying to air condition it cool. We propose to do the Caribbean in due course.
I don’t know what the actual running voltage is for these units. It is certainly something to ask the various manufacturers.

[Paul L]

You say you have 3 in of good insulation? Is this original with boat? If so it is probably not up to being used as a freezer in the tropics.

[Jolly Roger]

Oh heck! That's not good news, but this is the reason for my post.
It is original, circa 1977, but from what I'm able to see it looks solid enough and in good condition. When we have used the box with a bag of ice, one lasts a good day. There isn't much I can do about it anyway. The box is molded to the shape of the hull, plus 3", then the other sides are part of the kitchen molding.

[crazyoldboatguy]

I have read so many posts on the subject and have slowly come around to the air cooled concept. Kollman and others have provided ample evidence from small to mammoth installations that air cooled is as efficient, easier to install and - most importantly - less stuff to break. The extra heat pushed into the cabin is minimal altho you must make sure there is adequate space around the compressor unit.

If you are seeking to make the current box a "freezer" the recommended insulation is 6". If your unit is the original built in unit, it is quite likely the 3" insulation you believe is there......isn't. You may have to remove the entire unit and re-insulate. While your power supply may be sufficient to handle the load with the insufficient insulation, condensation will form as a consequence of the insufficient insulation and drip down onto other surfaces of the boat. If any of them are wood - mildew and rot will likely occur. Also, the condensation will likely saturate the existing insulation causing it to be less efficient, leading to cascading problems of more condensation and less efficiency.

I am also learning much about this stuff and watch these streams closely. I have learned a lot and will learn more. Good luck with your refit!

[Jolly Roger]

Thanks for the replies: I actually fitted Corian counter tops a year ago on top of the existing crappy Formica tops. In view of the age of the boat I think I better do as Crazyoldboatguy says and remove the counter top over the box, then cut the top off to see exactly what condition the insulation is.
If it is in fact no good I expect it might be possible to cut all the bad stuff out, then re-insulate with the correct rating new foam—whatever that is.
It’s classic isn’t it? What sounds like a pretty simple modification will probably turn out to be another major kitchen refit.

[crazyoldboatguy]

Murphy's Law only goes so far. Flaherty's Maxim to Murphy's Law states that Murphy was an optimist!

I have repeatedly run into the challenge of thinking I have a basic repair which ends up as a major refit. I am not a patient man. However, I have learned much and have become more patient. All because of being constantly humbled by my boat. My cruises start with the refitting and repairs. The list is part of the journey. The joy I feel in getting intimate with "the other woman" completes my life. The knowledge that the job has been done right and that I KNOW it has been done right because I DID IT, is a major source of satisfaction for me.

[Terra Nova]

Best reefer/freezer system I have installed is Frigoboat with keel cooler.

3" of insulation is inadequate.

[Paul L]

Another option is insulate the interior of the box, making it more efficient and smaller. You generally don't need a big freezer. I added 2 in of foam to the interior and then used shower liner white plastic as a cover for it in my old box.

[Dsanduril]

+1 - if you can give up the space add insulation inside the existing box. If you really want to go whole hog you can even use aerogel or vacuum panels. There are a couple of threads around here on the subject. Roy_M did a rebuild with several threads and some good supplier information.

http://www.cruisersforum.com/forums/...tml#post667042

http://www.cruisersforum.com/forums/...light=nanopore

[crazyoldboatguy]

Yes, you could achieve 6" insulation value within the 3" "footprint" using aerogel and/or vacuum insulation panels (VIPs). At a substantially greater cost. Insulating a 4.5 cubic foot freezer could cost hundreds of dollars to insulate with those materials. VIPs remain a fragile technology with longevity issues. Even if properly installed and NO ONE piercing the panels EVER, I understand they can leak over time to end up having no better effectiveness than the same thickness as foam. You would be back to having 3" of insulation. I am going to avoid them.

Polyiso foil backed panels offer quite good insulation, do not absorb moisture and offer better insulation than the pink board at a comparable cost. Not as good as the aerogel or VIPs but good enough to reduce the thickness of the insulation (you need an R value of 30 for a freezer) from 6" to 5". I am hoping that will be good enough for me.

One could mix materials as well. With 4" of polyiso and 1 layer of aerogel (0.4"), a person can achieve an R value of 30 at a reasonable cost and a 4.5" footprint. Any other combination would suffice.

Isn't this fun?

[a64pilot]

Any room for one of the portable fridge / freezers? Be a whole lot less stress

[Terra Nova]

The portables are extremely inefficient.

[Jolly Roger]

Hi guys,
Now I’m beginning to start to think:
I had not thought of insulating the inside of the box. This would be comparatively easy, but would of course reduce the capacity.
I’m pretty sure there never was 6” of foam, so I might have to do both.
I think, before we go any further I need to make an inspection.
This I can do this weekend, fairly easily since I did not glue the Corrian top down.
I will then slice the top of the box and see what it looks like, then report back for the best remedy.