Fermentation Chamber Designs

I invested some time learning Google Sketch Up, and am very pleased with the results. It takes a while to get some basic concepts down, but once you do, you'll find a very powerful and efficient tool.

Here's a screen shot of the latest of the designs of my fermentation chamber:



The basic idea is very similar to Jason's "Fermoire:" https://www.homebrewtalk.com/f51/fermoire-45567/

On the top shelf, I will place a compressor (probably an used one from a small ~2 cu. ft. fridge). The designs include a hole in the rear, which is not visible, to help ventilate the hot air created by the refrigerant system. Next to it I will keep a small tub of glycol (or other refrigerant-ish liquid). The evaporator coils will be submerged in this liquid. The liquid will be pumped to the other chambers, in the same manner as the Fermoire, where fans will blow the air across radiator fins.

On top of the middle shelf, a microcontroller (Arduino) will operate, reading temperatures from various probes. It will utilize this data to turn the fans, pumps, and compressor on and off, thus maintaining precise control over the temperature of the coolant and chambers.

The bottom shelf will be reserved for a bucket to use in conjunction with blow off hoses.

The blue things are recycled malt extract containers used as fermenters, measuring about 14.5" in diameter and about 26" tall. They hold about 15 gallons.

I will tweak the dimensions a bit, as this design is pretty large (3' 7.5" tall doesn't even include casters on the bottom!) and will also be very heavy. I hope to use a granite top, but may scrap that in favor of something less expensive and lighter.

I appreciate any thoughts or concerns. One thing I am particularly unsure about is how I will sample temperature of the beer. Ideally I read the fermenting wort itself, but that would be rather challenging. Sampling the temperature of the plastic, especially with a large fermentation, will certainly yield low temperatures.

Don't go through all that work and under size your compressor. Not sure if one from a mini 2cu ft fridge will be enough. I think it will run all the time and burn out, but I have no idea how you figure the correct sizing. It sounds like you want to keep 30 gallons cool, are you going to be lagering? Maybe someone else will have a good answer.

And put some eyes on that guy or he will bumping into the chamber!

samc said:

Don't go through all that work and under size your compressor. Not sure if one from a mini 2cu ft fridge will be enough. I think it will run all the time and burn out, but I have no idea how you figure the correct sizing. It sounds like you want to keep 30 gallons cool, are you going to be lagering? Maybe someone else will have a good answer.

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I'm skeptical about it too. I'll be doing lagering (the main motivation behind the project) so keeping 30 gallons in the 30's - 40's will be very stressful. The area designated to the compressor is quite a bit larger than the 2cu fridge compressor that I mentioned, but I should probably plan around a more suitable compressor. Anyone happen to have some approximate dimensions of, say, a compressor designed for a large chest freezer?

samc said:

And put some eyes on that guy or he will bumping into the chamber!

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That has always bugged me! That guy comes default with the template I selected.

i love these ideas, but in all respect... by that point you might as well just get a chest freezer right? all that effort seems a bit excessive unless you just want it to look good too. and even then you could just put a facade on a chest freezer, and a collar if you need to increase the height for your 15 gallon fermenters. to me it seems it would be much more efficient and much less work.

SowegaBrews said:

i love these ideas, but in all respect... by that point you might as well just get a chest freezer right? all that effort seems a bit excessive unless you just want it to look good too. and even then you could just put a facade on a chest freezer, and a collar if you need to increase the height for your 15 gallon fermenters. to me it seems it would be much more efficient and much less work.

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And that's the difference between you and me

You're absolutely right. But you must realize that this is largely a learning exercise for me. I know a lot about computers, but very little about construction or electronics, so this yields a lot of new experiences for me.

stephelton said:

And that's the difference between you and me

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trust me, i sat where you are sitting right now not long ago... here is my ill fated fermentation chamber idea...




by all means go through with it! This Thread.. will likely help you with demo-ing your fridge if you choose to do so...

Why the ill-fate? Looks like a good design and a fun project!

That link (and another it references) have some good info. One guy mentioned using a fan over the evaporator coils to help keep them from freezing. My coils will be submerged in water/glycol, so what I can do is position the inlet tubes such that when the pumps are on it pulls liquid heavily from the area surrounding the coils.

I ordered most of the electronics last night (all I need is a few more electrical relays and some tubing). The rest is building materials. The cost so far is already pretty steep, but not really more than I anticipated.

stephelton said:

Why the ill-fate? Looks like a good design and a fun project!

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Mostly lack of construction funds. I'm a broke college student, and I'll be moving soon so it sort of just didn't make sense to do it anymore. I designed it that way to conserve space (I'd already built the top shelf area with the fridge), but when I move I'm fairly certain I'll have room for a chest freezer.

In searching around for my project I came across a few threads and resources you might be interested in. This thread specifically... Fermentation Chiller (Pic's Included). Hope it helps. I'd be stoked if you complete it.

SowegaBrews said:

In searching around for my project I came across a few threads and resources you might be interested in. This thread specifically... Fermentation Chiller (Pic's Included). Hope it helps. I'd be stoked if you complete it.

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Sounds like a challenge

The pumps I purchased are a bit expensive: Dtek dB-1 Compact 12v DC Pump w/Tach Sensor I searched for bilge pumps with a 1/2" hose but was very unsuccessful. The pump I linked has relatively low throughput (looks like a max of about 132 GPH) but also a lot less current draw (and likely quieter).

Some of the bilge pumps I came across were "Automatic," some were not. I'm not sure what that refers to, but it could be an issue.

Automatic usually means that they either have or have the capability of working with a float switch. Level in the bilge get high, they turn on, when its low, they turn off. One of the greatest inventions ever for sinking your boat! - Dwain

I figured I'd revive this thread. Since I will probably have a lot more to say about the project, I figured I'd keep it all consolidated.

I'm writing some graphing utilities for my fermentation chamber and am able to produce a graph of the entire fermentation for the first time:



This is a beer I brewed Wednesday night. The brown is the internal fermentation, the grey is the amient air temp in the chamber, and the blue is the coolant. The black line is the target.

I pitched the yeast quite warm, unfortunately. Took a full 24 hours to bring it down to the target temp! I think I've got a project between now and next brew: counterflow chiller! That plus an ice bath and I should be able to pitch right at the target temp. Has anyone had any experience in controlling an immersion cooler through ice bath to hit a target temp?