10 Days of Cold in SOF Chiller

[BrewJohnson]

I recently built a son of fermentation chiller to make a bohemian pilsner for an upcoming family reunion. 4 days after brewing, I left town for 10 days for my kids spring break and stocked it with ice when I left. Amazingly, it was still at 50 degF when I got back and the fan wasn't running.

My modification of the standard SOF chiller design includes 2" thick Dow Tuff-R isulation (R-13) and a digital thermostat (both from Home Depot).

I ferment in my basement which is about 64 degF. When I left I put 4 gallons of ice jugs plus 4 small ice packs in the cold side. I figured it would run out of cold and warm up to 64 before I got back and I would get a diacetyl rest in the last few days of fermentation. To my surprise I had to warm it up when I got home.

If anyone would like information on my build, let me know.

 

[Photopilot]

Please share the details, as it is next on my list, I would like to see how you did yours.

 

[BrewJohnson]

I followed the basic plan from Ken Schwartz found here:

http://www.bayareamashers.org/gadgets/son_of_chiller.pdf

I couldn't find the pink extruded polystyrene in anything wider than 16" but my local HD had the TUFF-R rigid insulation in 4X8X2" sheets. This insulation has a better R value at R-13 and is wrapped with a radiant barrier material that makes a nice clean surface. The problem with it is that it is very friable and I had to tape all of the exposed cut surfaces with metallic duct tape, even after using a table saw for the cutting. It also doesn't flex much so you have to pay special attention to ensure that everything seals well. I used 1/4 round PVC molding as the backer strips for the weather stripping. I recommend using 3/8" or 1/2" weather stripping due to the lack of flexibility.

For temperature control I installed the rite-temp battery powered controller like the one described here:

http://www.wortomatic.com/articles/Remote-Sensing-DIY-Controller-for-Less-Than-$25

I think the one I bought was model 6022.

I may go back and split the top to have separate lids for the ice and wort chambers but overall I am very happy. I use 1 gallon "Simply Orange" jugs because they are made of PET and have a big wide cap. This allows me to easily stack washer fluid jugs on top of them without dowels. I am currently holding it at 40 degF and swap 3 jugs every 2 days.

Good luck with your build.