Large Fermentation Chamber

[rjhockey]

I brew normally with a few people and we do large batches currently our primary fermenter is a 14gal conical. We brew in the garage fill the conical and then carry it down to the basement. This is ok but I just bought the extension to make it 29 gal. Just going off the weight of water thats ~239 lbs not fun to carry. Sadly brewing in the basement is out of the question. So I need something to allow us to ferment at ale temps year round in a garage in the midwest. The garage fluctuates in temp but never over 95F and not below 40F.

I've been toying aroud with the idea of building a fermentation chamber using 6 x 2 inch r-10 foam board attached to plywood for structure and sealed in the corners with silicone and spray foam. Using a mini fridge with the door removed and shoved in like an ac for cooling and a heater for the cold winter.

Size would be 8'x 46" x 46" with the fridge and heater mounted near the bottom off to the side.

Has anyone done something like this and did it work?
Does anyone have an alternative idea?

Please help.

 

[Gruel]

Sounds great to me. Just two suggestions:
1) even though polyisocyanurate foam gets a bit worse at colder temperatures, I think it's still your best choice for insulation. It comes with aluminum (or aluminized paper or foil) on both sides, which is great as vapor barrier.
I don't see what the plywood would be good for, except maybe as a floor inside, to distribute the weight. The polyiso sheets are plenty sturdy to hold up their own weight.
2) Use aluminum tape (real duct tape for sealing ducts) to seal the joints and edges of your enclosure, inside and out. This will prevent air leaks and humidity intrusion. You can spend unlimited amounts of cooling power on condensing water out of humid midwest air.

Oh, and a third:
it's easy to compute your heat leak from the total area, the temperature inside and outside, and the R value of the foam. It is literally just
square feet times temperature difference in Fahrenheit divided by the R value. For example, 8'x4'x4' is 160 square feet times 50 degrees (80F - 30F) divided by 12 gives ~700 BTU/hr or ~200W cooling power needed just to compensate the enclosure heat gain in the best case (no air or moisture intrusion). That helps in picking a fridge with sufficient wattage.

 

[day_trippr]

The alternative idea: get your friends to pool their bucks for a respectable glycol chiller setup for that conical.
I suspect everyone will be happier in the end...

Cheers!

 

[burntchef]

FWIW,
I built a chamber going the mini fridge route and was disappointed with results. I would box the foam as you describe and insert a window unit air conditioner controlled with a ink bird. I am converting my 10 gallon chamber this week.
Eric

 

[Transamguy77]

I’m with @burntchef the last one I made had issues keeping things cold, worked great for keeping things warm.

I’m making another one now that is actually bigger and is closer to the size you are building and I’m using the same fridge but going to use a coolant running through it and a heater core as a heat exchanger to cool the larger space.

I agree with @day_trippr a glycol system would make it much easier than spending the time to build something that may work versus buying something that will work. I’m all about DIY but after dealing with trying to work with a ferm chamber that does not really work for years I think I would have done something different from the beginning that would work better.

 

[Gruel]

Even if you are throwing a kilowatt at it, you still need insulation. You are definitely on the safer side with a 1 HP (~750W in, 2kW out?) glycol system or a 6000 BTU/hr (~1700W out) air conditioner than with a 300W fridge, but you still can't set it up willy-nilly so it has to cool or dehumidify your whole basement or garage.

Do your numbers, size your system.

 

[Mtrhdltd]

I just upgraded batch sizes and had the same problem. I was able to run just under 20 foot of 3/8 line through the walls into the basement, fermenter stays in basement now. I realize that may not be an option for you. I have thought of the same chamber idea just with a window ac and a cool bot type clone. Good luck! I will be watching to see your solution and results.

 

[LTBrewer]

With the batch size and weight you are going with, I would look at solutions that didn't have me carrying hundreds of pounds up and down stairs and into fermentation chambers

 

[apache_brew]

Why not just carry the wort down in smaller sized sanitized containers and avoid the cooling system all together? Heck, can you run a hose and pump wort (gravity fall better yet) downstairs instead?