Ice Box Rebuild

[Lew Morris]

Good morning to all hands,

My partner and I recently purchased a 1985 Dufour 39 (German Frers design). This past August during our trip up the coast from San Diego, it became painfully clear that the ice box on the vessel is inadequate. We went through a LOT of ice in only seven days.

It's simply that, an ice box. The refrigeration unit dumps cold air (when we're on shore power or the engine is running) onto the top of the storage area and thence it turns back into warm air... and runs off into the bilge.

I haven't started an internet search for "refrigeration" components yet. Can anyone suggest insulation material(s) and other hardware are suitable for the purpose.

It looks like a total cut-out-and-refit-new job to us, but we're open to suggestion at this point.

Thanks.

Lew Morris

[gonzo]

Can you pour expandable foam around the box?

[Lew Morris]

hi Gonzo,

it's a very tight fit with limited access. it's pinched between the oven and the back of the settee.

i'd though about foam..... there is an amusing account of the use of foams on the Dufour owners webswite. seems the guy got a little over zealous with a can of it and foamed all of the silverware, and the drawers into his galley cabinet . .. .. .

i've been messing with finbreglas, etc. for years and think i can use it in one area; behind the box, against the hull.

for the rest of it i was thinking of some unobtainablee, super-whamadyne sheet material maybe. i guess the fishing industry uses a silvered sheet material to line catch boxes but i haven't been able to find brand names.

as i mentioned, it looks like a surgical removal of the old unit is what's really required. followed up with some cabinet rework.

Lew

[GordMay]

Try the library at "Glacier Bay". They've some interesting articles.
http://www.glacierbay.com/Library.asp
Regards,
Gord

[gonzo]

The shiny material is the same the sell as space blankets or survival blankets. NASA and army surplus stores carry it. It reflects heat and should help a lot.

[Lew Morris]

Gord,

thanks for the headsup on GalcierBay's products.

pricey stuff, but it looks like the answer to our problem.

Lew
35N 120W

[yipster]

not directly thread related i recall the d.i.y. cool boxes. working on a low Ah "peltier?" element. anyone knows what i'm talking about and have some info?

[GordMay]

"Kool-A-Tron" and others make Pelletier Effect coolers.
Pelletier Effect heat pumps operate at a maximum Delta T of 40 degrees F - hence if the hot-side element is at 90 deg. - the minimum theoretical cool side would be 50 deg. Not very useful, I'd think.
OMO
Gord

[yipster]

Gord
i know now what to look for. had been reading about such elements and that one can built his own box. a quik search for kool-a-tron shows pricing is frendly.
ok it isnt a blood heat weather freezer but if it works as said it cools for a fair price. i'll check Ah use also.

thanks
yipster

[SuperPiper]

I have a Kool-A-Tron! Please explain in dummie-terms what is a Pelletier Effect element.

[yipster]

do you like the cooler?
in the words of kool-a-tron: This refrigerator utilizes the refrigeration power of thermoelectrics, rather than a noisy compressor, and it can cool up to 45°F below the ambient temperature - plus it functions as a thermoelectric heater too!
i recall reading -but have to check again- it had a low Amp usage and some other advantages. let us know what you think of your box please!

yipster

[rjmac]

Theoretically you should be able to series these devices and get (ambient - 40) - 40 = -80 from ambient....... or on a 110 Deg. F day a inside temp of 30 Deg. F.

But it will cost about 10amp draw at 12v.

I recommend a chest arrangement because the cooling rate is not that fast.

[SuperPiper]

Kool-A-Tron: adequate provided the contents were cool to start.

What is the mechanism for transferring heat out of (or into) the chest? The only moving part seems to be a fan mounted over a heatsink.

[GordMay]

The basic concept behind thermoelectric modules (TEMs) is the Peltier effect.

The Peltier effect occurs whenever current passes through the circuit of two dissimilar conductors; depending on the current direction, the junction of the two conductors will either absorb or release heat. The amount of heat pumped is in direct proportion to the current supplied.

The Peltier effect is utilized to its maximum when thermocouples are made of material of different conductivity. The most commonly used materials are Bismuth Telluride doped with Selenium and Antimony as semiconductor material. Thoroughly refined ingredients are alloyed together to result in polycrystalline semiconductor material with anisotropic properties.

To make up a TEM, thermocouples are connected electrically in series and thermally in parallel and sandwiched between two ceramic substrates.

lotz of info'here:
http://<b>http://www.ferrotec.com/us.../index.htm</b>
FerroTec USA - Thermoelectric Modules

Regards,

[yipster]

thanks for the input, i'm up for again a new cooler and find this interesting.

the site: http://www.ferrotec.com/usa/thermoel...ic_modules.htm
the brochure: http://www.ferrotec.com/pdfs/Tebrochure.pdf

yipster