Vintage Kegerator Insulation Question: R-30, R-19, or R-13.

[MrFoodScientist]

So I scored a vintage (I believe 1949) 10cf fridge off of craigslist.

I can fit 3 cornies on the floor, and could likely stagger another 2 if I could find another 1/2" of space.

I was cleaning it up last night and found nasty blackness in the door insulation(hopefully I didn't just invite toxic black mold into my apartment). It's also been seeping water from somewhere around the skirt while it's been unplugged that I assume is condensation that has soaked the cabinet insulation. I can only imagine what's living in there.

I've read other vintage kegerator build threads (Special thanks to kerber for his other advice already via PM) where they've replaced the insulation with R-30 or R-19 insulation.

There's roughly 3 1/2" between the inner cabinet and the outer cabinet, but R-19 insulation is 6 1/2" inches thick and R-30 is 9 1/4". Wouldn't I do just as well to use the R-13 that's 3 1/2" so I don't compress it and lose R-value?

I've never installed insulation before, so I'm not sure how snug the fit should be, but I understand the R-value concept and I know I'm going to lose some of it to compression.

I suppose I could dig up kerber's thread to look at his temperature profile over time and do the math to see what R-value he's getting, but I just wanted to throw that out there to see what the consensus was.

Any thoughts?

 

[marinosr]

Edit: Nice fridge! Post pics once the build is done.

You're correct. You want to use appropriately-sized insulation, as thermal conductivity of insulation rapidly increases with compression. For instance, the chart I've hyperlinked below states that R-19 insulation has an effective R-13 value when compressed to 3.5". You're not losing anything, so just use the R-19 if you have some laying around, but just get the cheaper stuff if you're buying it.

Foam panels have an R-value of around 5 per inch, so you could get an R-17 or so value with foam panelling, but the edges would need spray foam or something, which isn't a superb insulator, so it may be a wash with cost factored in.

http://webcache.googleusercontent.c...df+&cd=2&hl=en&ct=clnk&gl=us&client=firefox-a

 

[MrFoodScientist]

Thanks, marinosr, that's what I suspected, but wanted to be sure. Since a roll of R-13 is only about $10 from Lowes, I think that's the best option. Now to properly dispose of the rock wool that's in there without giving myself emphysema.

 

[MrFoodScientist]

Awesome! I just found probably a good 2 gallons of water hiding in the bottom. The bottom layer of insulation was completely soaked! That dark stuff is about an inch of standing water. I had a whole lot more come out with the insulation. My apologies for the crappy picture:



I guess I'm stopping here for the night, otherwise the shopvac is going to wake everybody up.

Would anyone know if this is from condensation between the insulation and the inner cabinet or if it's more likely to be from improper defrosting? I'd hate to replace the insulation and find I have the same problem at some point down the road.