Building an Igloo....Cooler

So I have been thinking about the rising temps here in Nevada and the temps associated with brewing beer and getting quite concerned. I know that there is a plethora of info here on the forum about this that and the other ways of keeping your brew cooled and have finally settled on the tried and try cooler solution. However that got me thinking even more. Could you not just build your own?

Now I know you can, but being a beer snob and an IT guy kind of leave me lacking in the building department. Don't get me wrong, in my day I could build some really nice cabinets, and have, but I have never had to keep the contents cool. That is where I need help, I know little to nothing about insulation.

Now I know all an ice chest is, is foam with plastic sandwiched around it, and well I guess I better get to the point.

After the cabinet is made we would have to worry about three types of thermal contamination, radiative, conductive, and convective. The foam board insulation should take care of the last two, but what about radiation? So what I have been thinking is using the Reflectix foam bubble wrap in between the wood paneling and the foam board.

Now the question is, will this work? Is it even worth it? What "R" rating would you need to keep the cabinet in the 60's while it is sitting in a 100+ degree garage? Maybe the master home builders on the site can answer this question. Thanks!

Also, I know that "R" is the amount of thermal resistance, but how does 1 R relate to degrees? Thanks!

Your question really can't be answered without knowing what cooling method you are going to use. All the R value of your insulation is doing is delaying the transfer of heat. You still need something to cool the inside of your insulated box. The efficiency of your cooling system will determine what level of insulation you need and vice versa.

See now I guess that would have been a handy bit of information for me to include. No wonder I never get any comments to my posts.

Anyway I will be using a pc case fan and ice bottles.

Also, the most reliable info I can find on the web indicates that the 5-day cooler has an r value of 6.3.

Keep in mind, wood absorbs a lot of heat. If your exterior walls are to be wood you may need to beef up your r value. plastic or fiberglass will not absorb as much heat and will aid in the delay of heat transfer.

I really wouldn't know how to go about determinig efficiency on something like that. My opinion would be that this would be adequate to keep ale ferm temps with an r value greater than 6, however I don't know about lagering temps.

If you go ahead with the project, please keep us updated with the results.

Thanks! Oh and it will pretty much be for ale temps anyway. If I do it I will be sure to let everyone know how it turns out. Thanks again.

The only other thing I am still wondering is, will the foil bubble wrap help any? Guess I may just have to try and find out.

I have been thinking about this as well. I think I am going to try and build an insulated box with some spray foam from the Home Depot in something like a concrete form. Not sure how I will laminate it, but it is kinda like building a jacuzzi (which uses vacuum forming). Technically, you are not cooling what is inside, rather you are drawing the heat out of it. I don't think these top loading freezers are 21st century technology, they are an insulated box with something to draw the heat out of them and a thermostat. I'd be interested to hear more about what you are thinking about doing.

chachi said:

I have been thinking about this as well. I think I am going to try and build an insulated box with some spray foam from the Home Depot in something like a concrete form. Not sure how I will laminate it, but it is kinda like building a jacuzzi (which uses vacuum forming). Technically, you are not cooling what is inside, rather you are drawing the heat out of it. I don't think these top loading freezers are 21st century technology, they are an insulated box with something to draw the heat out of them and a thermostat. I'd be interested to hear more about what you are thinking about doing.

Click to expand...

If I'm remembering my high school physics... (been a while.) Heat flows from hot to cold. So the Ice bottles absorb the heat from inside the box. So you just need to supply enough Ice to absorb the heat and provide enough insulation to keep extra heat from entering the box. :fro:

You are correct, cooling is actually removing heat....heat is generated from energy. The radiant energy from the sun heating the garage will pass to the box. The r value is determining the resistance of the heat transfer from one medium to another. But, you will have heat created from fermentation to deal with as well. And the big thing to remember is, since you can't erase energy, you can never stop the transfer of heat, just delay and diffuse it.

I got to thinking more about the skin (outside) of the box. If you use wood, I would go as thin as possible, like paneling. Even 1/4" plywood is going to absorb considerable heat as compared to a plastic skin on a cooler. And, yes, my opinion is the bubble wrap is inexpensive enough so why not add a layer. It may not provide much protection, but you aren't going to hurt anything either.

i have been batting this idea around for a while also. but with a diffrent twist.... I have been looking at using cardboard as the exterior wall lined with some sort of foam or spray foam.... would that be fesible? i think it would be alot ceaper for a beer cooler in a garage... no great looker....

sorry to piggyback....

Hey no big deal. I don't know if cardboard would work or not, but it just may. Right now I am looking at some sort of plastic to use as the walls of the box, maybe plexiglass, but that is not really the cheapest way to go. Lots of options here.

I don't see why cardboard wouldn't work. Using spray foam can be messy and tricky, but definitely doable and cheap. Or you could just use duct board and hold together with silver tape (kinda like duck tape only shiny silver witha peel away backing).

You could always look into a 38DD fermentation chiller.
http://www.wortomatic.com/articles/38DD-Mother-of-a-Fermentation-Chiller

Also searching for "son of fermenatation chiller" should find some good plans as well.

EvilTOJ said:

You could always look into a 38DD fermentation chiller.
http://www.wortomatic.com/articles/38DD-Mother-of-a-Fermentation-Chiller

Also searching for "son of fermenatation chiller" should find some good plans as well.

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great link! Now I have a project to start this weekend.