R Value of materials/refrigerator

I did a quick search and did not find any information on the subject of R value

Does anyone know the R value of the standard mini fridge or chest freezer (estimated average)

the topic seems to come up often with collars and such... was thinking we could all get together with our knowledge and put together a list of popular things to get ideas on building fermentation chambers/custom bar fridges, ect

R value of wood (say 1 inch oak)
1 inch pink foam
foam with aluminum foil backing
ect...

anyone care to give input on this subject?

BreWirfel said:

the topic seems to come up often with collars and such... was thinking we could all get together with our knowledge and put together a list of popular things to get ideas on building fermentation chambers/custom bar fridges, ect

R value of wood (say 1 inch oak)
1 inch pink foam
foam with aluminum foil backing
ect...

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The R values are listed for common materials. Just google "r value common materials".

Soft lumber has an R value of 1.25/inch. So, a 2x[4, 6, 8, 10] has an R value of 2 which is very poor.

BreWirfel said:

Does anyone know the R value of the standard mini fridge or chest freezer (estimated average)

Click to expand...

Modern kegerators/mini-fridges have 1 - 2 inches of in-place foam. So, considering the interior and exterior shell, they have an R value of 8 - 14.

Chest freezers are usually 2 - 3 inches thick since they are designed to maintain freezing temperatures. So, an R value of 14 - 20.

wow..great link. thanks.

lamarguy said:

Modern kegerators/mini-fridges have 1 - 2 inches of in-place foam. So, considering the interior and exterior shell, they have an R value of 8 - 14.

Chest freezers are usually 2 - 3 inches thick since they are designed to maintain freezing temperatures. So, an R value of 14 - 20.

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I think you're high. You R values that is. The high-tech chest coolers are advertised with an R value of 7. I would guess the average cooler is the 4-6 range. Foam insulatuon has an R value of 3-6/in depending on the type.

My coldbox will end up at 11-12 with 2.5 inches of foam.

From what I've seen, most fridges are indeed in the 6ish range, max.

arturo7 said:

I think you're high. You R values that is. The high-tech chest coolers are advertised with an R value of 7. I would guess the average cooler is the 4-6 range. Foam insulatuon has an R value of 3-6/in depending on the type.

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It's a simple calculation. Extruded polystyrene (very common in commercial application) has an R value of 5. The average refrigerator insulation is at least 1 - 2 inches thick, so a minimum R value of 5 - 10. Then, you consider the shell (inside and outside), and you gain 1 - 2 points.

So, an inefficient fridge is R 6. An efficient fridge is R 11. Freezers have even thicker insulation, so scale as necessary...

Here's an example R value calculation from a wine cooler company.

Still think I'm high? Or, are you just a buzz-kill? Ha.

Lams, I just re-read your post. My bad. I interpreted "chest freezer" as "chest cooler."

cheers

I'm building a walk in cooler in my basement. If a chest freezer only has 14-20 does that mean that thats all I need for the walls of my cooler?

the better your enclosure is insulated the less it will cost to operate. if i were building a walk in or keezer i would ere on the side of to much insulation. and not worry about what i can get away with.

R #'s are crazy. after i bought my house and saw the certification of "R-30 minimum" in my attic, i searched building code, R's, etc. wow! i spent a few hours and don't really know much more than when i started.

I'm not trying to get by with the bare minimum, I am just tight on space. Building walls 2x4 instead of 2x10 will save me a ton of valuable space. So I'm leaning towards 2x4 walls insulated and skin with wood or styrofoam insulation.

bdennis said:

I'm not trying to get by with the bare minimum, I am just tight on space. Building walls 2x4 instead of 2x10 will save me a ton of valuable space. So I'm leaning towards 2x4 walls insulated and skin with wood or styrofoam insulation.

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you can only fit what you can fit if you only have 2x4 to deal with use the best insulation you can find and make sure it is sealed. a small air leak makes a much larger difference than the R value of the wall. also make your door the same R value as your wall, build it out of 2x4s and use the same insulation and put a seal on the inside and the out. (and maybe one in the middle) As to not create a weak link.
its pretty spendy but S.I.P.S. structural insulated panels are pretty awsome, i plan to use it for my own walk in one day.

Use 2x2s or even 1x2s instead of 2x4s whenever possible. Cut styrofoam scabs to fill the difference. R-value of wood is about 1 per inch, so you loose a ton of temp through wood that touches both outside and inside your cooler.