My Fermentation Chamber Build

I'm in the process of switching from extract, basement-ambient-temp brewing to all-grain, controlled-temp brewing. I'm currently working on constructing the fermentation chamber.

The outside dimensions of the chamber are 48" x 48" x 43". I plan to add approximately 3.5" of rigid foam board insulation, which will then be covered with FRP.

The chamber will be kept at 60F and cooled utilizing a standard mini fridge. Here are some pics of the current progress. Next step is adding the insulation.

cant wait to see this. place holders kind of take the fun out of tracking a project and getting all peoples comments in line - just a suggestion.

FRP? Chicago? You wouldn't happen to be a sailor would ya? I would sure love to do a Chi-Mac one day.

kegtoe said:

cant wait to see this. place holders kind of take the fun out of tracking a project and getting all peoples comments in line - just a suggestion.

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Your wish has been granted. Place holders deleted.

itsme6582 said:

FRP? Chicago? You wouldn't happen to be a sailor would ya? I would sure love to do a Chi-Mac one day.

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Used to be in the Navy, but had a desk job. That was good though, as I get horribly sea sick.

kegtoe said:

cant wait to see this. place holders kind of take the fun out of tracking a project and getting all peoples comments in line - just a suggestion.

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It's nice to see everything at the front of the thread. Some of the epic build threads on here get upwards of 50 pages and the BS comments make it a pain to read through, like this one.

Just a suggestion.

How are you going to incorporate a mini-fridge to cool the chamber? You can't just stick one in there with the door removed if that's what you're looking to do. You'd have better luck using a full sized refrigerator and stripping its guts as was done in another build around here.

Here's the thread: https://www.homebrewtalk.com/f51/kcbrewers-garage-brewery-220050/

He'll likely do what several people around here do and butt the opening of the fridge (door removed) up to an opening of the chamber and seal the edges. Essentially expanding the interior of the mini fridge.

IrregularPulse said:

He'll likely do what several people around here do and butt the opening of the fridge (door removed) up to an opening of the chamber and seal the edges. Essentially expanding the interior of the mini fridge.

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Yeah, I of course just read about those. And, what a neat idea! Hmmm

IrregularPulse said:

He'll likely do what several people around here do and butt the opening of the fridge (door removed) up to an opening of the chamber and seal the edges. Essentially expanding the interior of the mini fridge.

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Bingo.

This is cool. I am thinking about doing the same type.

Nice, close in dimensions to the eventual build I want to do.. So many things to do.. so little time...

Progress on this has been very slow. Nothing has been done on the physical construction of the box. However, I was able to get my temperature control box completed. It's an aquarium dual-temperature controller from ebay.

Side view. Orange is the power cord. The small black wire from the side is the temperature probe. The outlet on the top is for the heater and cooler (one outlet per device).



Front view.



Front view with power. (Controller only displays in C, but that's what you get for a whole temperature control box under $30)

glad to see your making progress on yours, mine has had no progress since fall. Twins on the way, getting a nursery together, motorizing my grain mill, assembling cribs, installing carpet.

I snuck something in there for myselff

Picked up the insulation yesterday and was able to get it installed in the floor. More to do tonight. Will post pictures of the progress later tonight.

Subscribed.

I was just up at MDHB yesterday, good to know there's locals on here.

I've been thinking of something like this myself, although I was maybe going to use a window A/C instead of a minifridge.

Assuming you are gonna have a fan sitting in the mini fridge? Thats what I do with mine. Plugged a power strip into the "cool" oultet on the temperature control and plugged the fridge and fan into the strip. So the fan only runs when the fridge does.

brettwasbtd said:

Assuming you are gonna have a fan sitting in the mini fridge? Thats what I do with mine. Plugged a power strip into the "cool" oultet on the temperature control and plugged the fridge and fan into the strip. So the fan only runs when the fridge does.

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That is correct. I also plan to use the reptile heat rope for the heating capability.

Made some good progress on the fermentation chamber build. I installed the 3.5" of rigid foam insulation in the floor cavity. I then installed a sheet of 1/2" plywood over that to provide added support for the fermenters.

I also installed the 3.5" of rigid foam insulation in the ceiling cavity. These two sheets (2" and 1.5") were installed using a paneling adhesive. They are currently clamped/supported and will be allowed to dry overnight. A pic of the current state below:

subscribed

Ace_Club said:

These two sheets (2" and 1.5") were installed using a paneling adhesive. They are currently clamped/supported and will be allowed to dry overnight.

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3M spray adhesive works great tacky in a minute and permanent enough in case you need to make changes. No need for clamps.

Celsius is way better anyways. Makes life much easier to figure out when water boils at 100 and freezes at 0. Go Metric!! Woot!

How is this build going Ace Club? I just started my chamber with similar dimensions and a CL mini-fridge today. Hope it's going well.

Subscribed!! WOOT WOOOOOOOT! Just got rid of my aquarium fermentation chamber. Plan on rigging one of these up soon.

did you special order the insulation? I seem to have a hard time finding thicker than 1" here in TX

TheYoshi said:

did you special order the insulation? I seem to have a hard time finding thicker than 1" here in TX

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Nope, just picked it up from Menards and strapped it to the roof of my Corolla.

They carried thicknesses up to 2" in the store.

StittsvilleJames said:

Celsius is way better anyways. Makes life much easier to figure out when water boils at 100 and freezes at 0. Go Metric!! Woot!

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And that about sums up mine and everyone else's Celsius knowledge. I'm not sure the title celsius 233 would have been such a great seller.

Looking good. Keep the build going.

-cheers

I'm going to be scouting out a reclaimed building materials place for a cabinet that will fit a few carboys. If I come up short, I'm curious what does all the wood cost at a big box store for a basic build like this?

Crap, you guys digging up this thread are making me think about actually finishing this project. It has sat, languishing, for months now.

As for the cost of the wood, I think the base lumber was around $40 to $50. Could probably get that number down lower if you use thinner plywood.

Progress has been made!!

Today I was at Target and saw that their mini fridges were on sale, so I picked one up and continued my build.

From this image, you can see that I've finished insulating the back wall and have started taping some of the seams with Aluminum Foil tape.



This shot shows the side wall with the mini fridge installed. This wall still requires the addition of a 2" thick piece of insulation.



A side shot showing the mini fridge through the wall.



All that's left is the 2" side wall insulation, the fourth wall/door and its insulation and installation of the FRP flooring. Then the seams will be caulked and the chamber will be turned on.

looking good. im just about done with mine, but i just used 2" of insulation and was thinking that would be enough to hold lagering temps. should i add more insulation?

nootay said:

looking good. im just about done with mine, but i just used 2" of insulation and was thinking that would be enough to hold lagering temps. should i add more insulation?

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Depends on the size fridge you are using, the normal ambient temps (i.e., how great a temperature difference you are trying to maintain) and the size of your chamber.

That fridge is very small... I have to wonder if it can provide the cooling power you need for a chamber that size.

emjay said:

That fridge is very small... I have to wonder if it can provide the cooling power you need for a chamber that size.

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The calculated heat load for the chamber (using conservative numbers) ranges from 50 to 100 BTU/hr depending on the temperature difference in my basement. The cooling capacity of the mini fridge is 232 BTU/hr. This gives me margin so that the duty cycle time is low for the unit.

Ace_Club said:

The calculated heat load for the chamber (using conservative numbers) ranges from 50 to 100 BTU/hr depending on the temperature difference in my basement. The cooling capacity of the mini fridge is 232 BTU/hr. This gives me margin so that the duty cycle time is low for the unit.

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Ah, for some reason I thought this was going in your garage, in which case it might not have been able to keep up in the summer.

Just for the sake of my own calculation (different from yours), what's the r-value of your insulation, as well as the temp range in your basement? I'm interested in determining the particular capabilities of that system, for the hell of it (and since eventually I'll want to replace my chest freezer with something similar.)

emjay said:

Ah, for some reason I thought this was going in your garage, in which case it might not have been able to keep up in the summer.

Just for the sake of my own calculation (different from yours), what's the r-value of your insulation, as well as the temp range in your basement? I'm interested in determining the particular capabilities of that system, for the hell of it (and since eventually I'll want to replace my chest freezer with something similar.)

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R-value = 17.5

Temp range in basement = 60F to 75F

Are you sure about that 232 BTU cooling power? After doing the calcs, it seemed to be off a bit, and after some quick checking, it definitely seems to be unusually strong for a fridge anywhere near that size.

Because 232BTU would support a temperature delta (in your case) of between roughly 40-50° (depending on a few things)... even at the high end of your temperature range AND the low end of the cooling capability, you'd still be able to lager in that thing. The idea that it could support, essentially, a giant freezer, seems a bit strange.

What particular model is it? If that figure is accurate, I may want to get the same one!

232 BTU/hr is the cooling power listed for the compressor that comes with the fridge. However, you'd want to keep the load that you are cooling at no more than 50% of that to ensure that you don't burn it out by having it run all the time. Plus, accounting for inefficiencies and everything, it's realistically around 150-175 BTU/hr, which is still adequate for this application.

Since the box is small(ish) and well insulated, and because there isn't a huge heat load, it should be fairly easy to maintain the required temps with a low duty cycle.

With this box, the fridge will probably run quite a bit to get the starting temp down, but then it should be pretty easy for it to maintain the temps, assuming I have no huge leaks to the outside.

Ace_Club said:

With this box, the fridge will probably run quite a bit to get the starting temp down, but then it should be pretty easy for it to maintain the temps, assuming I have no huge leaks to the outside.

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It does seem like a big box for a small fridge. However, you do have it well insulated, so hopefully you'll be good.

TIP: Regarding getting the starting temp down - Freeze a bunch of water bottles or make a bunch of ice cubes in your main freezer/fridge ahead of time, and set them in the chamber at the start to overcome the initial heat soak. Take 'em out when the temp has come down. No sense making your little fridge work so hard.

Four of the 1 liter bottles of ice will provide over 1000 BTUs as it melts ( ~8 pounds * 144 BTU/# through phase change = 1152 BTU), plus a bit as freezers are ~ 0F, so another 60 BTU going from 0F to 60F. Small would be best so they melt faster to absorb the heat.

Also, could you show your calculations for BTU/hour? I came up with ~55 BTU/Hr for a 4x4x4 box with R 17.5 and a 15F delta.

( 64 sq ft * 15F delta * 1 Hour ) / ( 17.5 R Factor) = 54.9 BTU/ Hour

Is the difference a fudge factor, or is my calc off?

Project looks good!

-kenc

kenc_zymurgy said:

It does seem like a big box for a small fridge. However, you do have it well insulated, so hopefully you'll be good.

TIP: Regarding getting the starting temp down - Freeze a bunch of water bottles or make a bunch of ice cubes in your main freezer/fridge ahead of time, and set them in the chamber at the start to overcome the initial heat soak. Take 'em out when the temp has come down. No sense making your little fridge work so hard.

Four of the 1 liter bottles of ice will provide over 1000 BTUs as it melts ( ~8 pounds * 144 BTU/# through phase change = 1152 BTU), plus a bit as freezers are ~ 0F, so another 60 BTU going from 0F to 60F. Small would be best so they melt faster to absorb the heat.

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That's a good idea, I may try that.

kenc_zymurgy said:

Also, could you show your calculations for BTU/hour? I came up with ~55 BTU/Hr for a 4x4x4 box with R 17.5 and a 15F delta.

( 64 sq ft * 15F delta * 1 Hour ) / ( 17.5 R Factor) = 54.9 BTU/ Hour

Is the difference a fudge factor, or is my calc off?

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Your calc is off slightly. Your area is only assuming four of the six sides of the chamber. Bump that up to 96 sq ft and you'll be using the same numbers I do. (Also, the hour unit is included in the R factor, so no need to include it separately.)

Again, those numbers are a little conservative as the 4x4x4 is the approximate outside dimensions of the box. The inner dimensions are slightly smaller due to the insulation thickness and other material.

Ace_Club said:

Your calc is off slightly. Your area is only assuming four of the six sides of the chamber. Bump that up to 96 sq ft and you'll be using the same numbers I do.

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Ahhhh, brain fart - I was doing volume rather than surface area - thanks for straightening me out.

Please report back on how this works for you, it looks really good. What did the insulation cost?


-kenc