Fermentation Refrigerator Build

[dfouty]

I am planning on taking my old small mini fridge and make a new insulated box for it but use the refrigeration components from the fridge. Effectively making my small mini fridge into a larger fridge to ferment my beer during hot summer's.

I found surprisingly little information on the internet so far. I'm wondering if this is a good idea and what material would be okay to use for the new box? I was thinking PVC sheets with foam insulation on the outside.

Any help would be great,

-Dave

 

[BadWolfBrewing]

I've seen a couple threads on it... it looked pretty awful to chip out the insulation of the fridge to get the coils out. That was a newer fridge though. An older fridge just has the coils on back for expelling heat and the coils in the freezer shelf for cooling the interior. Probably easier. Either way, be super careful when doing it. Once a line with refridgerant is punctured, the fridge is shot/

For my first box, I just used 2" rigid insulation foam duct taped together. It was bright pink. And had the pink panther logo on it. My wife (then girlfriend) was not a fan of it in the living room. Worked great and was super cheap / easy though. Cut the foam with a putty knife.

 

[raouliii]

Just consider that as the internal volume of the new chamber increases above the original volume of the mini-fridge there will be a decrease in its ability to extract heat from the volume. This will be much more of a problem if the unit is placed in an un-conditioned (cooled) space. There will also be an increase in temperature stratification/zoning within the volume, unless air movement is maintained across the evaporative module.

 

[dfouty]

Yes I understand. I have thought of these things. The mini fridge gets quite cold. Below freezing for sure. But I haven't done my thermo calculations yet to make sure. I am also planning on adding a small fan to provide circulation. I'm still unsure about material for the outside. I may go with the insulation duct. I want it to be very durable though.

 

[BadWolfBrewing]

Whatever material you go with, make sure it is bright pink. I swear it makes better beer.

As far as temp goes, for fermentation you are probably fine, as long as you include a fan. In mine, lagering was only possible if the room it was in was also pretty cold to begin with

 

[dfouty]

Hmm... Bright pink sure narrows down my options!

 

[broadbill]

keep an eye on your material costs....used small chest freezers can be had off of Craigslist for cheap, maybe cheaper than what you can do this project for DIY. If the freezer works and fits a fermenter, you are done. It can also do lagers/lagering which I'd be surprised if a dorm fridge can handle.

 

[balrog]

Lowes has blue 2" rigid foam. I made one to surround a little 1.7cuft and have used it to keep 60°F 6G Ale Pail happy. It did struggle to bring 72° post boil, chilled "most of the way" wort down to 65° pitch temp, going about 45-50min/degree.

But there are color options available, at least if you are near a Lowes.

 

[Konadog]

I wouldn't wast the time and effort to pull the mini fridge apart, just remove the door and build a small box off of that. I just finished making one from scraps, mini fridge was donated to me, all 2 x 4's and plywood were scraps from previous projects, I only had to buy the foam board and hinges, $25 and done!