2 tier, 2 zone fermentation chamber build (AKA Racer X)

[Mtn_Brewer]

OK, time to post up. I got the idea for this build from Zacc's build:

https://www.homebrewtalk.com/f51/2-zone-fermentation-chamber-build-344775/

I've used a chest freezer and fan heater controlled with a Ranco temp controller for awhile. It works OK but I brew a lot of lagers and it was kind of a pain to have to coordinate all of my brews Having a fermenter with 2 zones was the obvious answer. I used Zacc's idea for the basic design and then came up with some innovations. I decided that I wanted everything to be as internalized as possible, including the heating and cooling elements. I also wanted it to be large enough that I wouldn't feel the need to upgrade in the forseeable future. I spent a lot of time designing it in a spiral notebook, who needs sketch-up? I configured it so that I can fit 6 carboys into each chamber and still be able to panel it with 4 x 8 sheets of plywood.

OK, so here's the build...

 

[de3isit]

Nice looking build.

Can you give some details on the changes you made to your design? Maybe some inside pics?

 

[Mtn_Brewer]

I first built the base from 3/4 inch plywood and a 2 x 4 frame. The top layer of plywood sticks out 2 inches on all sides. I insulted it with 3 1/2 inch batt insulation with an R value of 13. I built the sides and top in sections and then attached them. The dividing section was then added and insulted with some foam board insulation and batt insulation. The AC hole took some time to figure out. I wanted it to be at the right height to fit in next to my work bench and also to allow the AC unit to be removed and serviced/replaced if needed in the future.

 

[signpost]

That thing is awesome! :rockin: I'd still love to see some inside pics of the final product.

 

[Mtn_Brewer]

The cooling system for the top chamber uses a fan to drawn air from the lower (lager) chamber and spit it out on top. Zacc and other used pipes inside the chamber and computer fans but I wanted to internalize the circulation system. I worked out this pan to use the bathroom fan in the wall and built the ducts using PVC piping. The recirculation system on the opposite side spits the air out over the top of the AC unit. The PVC pipes were connected together and secured in place with epoxy and metalic duct tape. I paneled the inside with 1/2 inch plywood, trying to get as tight a fit as possible.

 

[Mtn_Brewer]

Once the inside structure was done and the venting was installed, I sealed the seams with some industrial strength caulking and painted it. For the heat sources, I spent a lot of time researching wall heater units. I decided on the Broan 120 heater. It can be rewired to 500 watts at 120volts in about 5 minutes by following the instructions. I found them on-line for $60 each. I installed them in the vertical position because the air intake is on the bottom and the output is on top. I mounted them high enough that they will not blow directly on the carboys. I used a sheet of flooring from Home Depot, that I glued directly to the plywood and then sealed with caulking and re-painted.

 

[Mtn_Brewer]

The control panel was built out of a steel junction box I got at the local recycling facility. I put painter's tape down to cover it and drew out the design. I cut the holes with a dremel tool, drill and file. I built an external fuse box using a metal outdoor outlet box. It is lockable to prevent curious kids from electrocuting themselves but allows fuse changes without having to remove the front panel.

 

[Mtn_Brewer]

I wired all the components to the side and insulated the whole thing in 3 1/2 inch batt insulation, trying to get as good a seal as possible with the vapor barrier. I closed it in with 1/2 inch plywood and then painted it with Behr Premium Plus Ultra, which is water based but extremtly durable and mildew resistant (if you believe the packaging). Before pulling through the wires, I put the control panel over the spot it would be and drilled the holes. Once the paint was dry, I pulled the wires through and secured the box with lag screws. I installed the buses and ground bar and got to work on the wiring.

 

[Mtn_Brewer]

I wired up the positive bus and then pulled the wires through to the fuse box. I used AGC fuse holders I got from the local electronics store. The AC, cooling fan and heaters are controlled with single pole contactors. Despite my best efforts, wiring got messy fast.

 

[Mtn_Brewer]

The control panel has 2 Auber 1/4 DIN PID's as the main controllers. The toggle switches next to the PID's power each one up individually and also the respective heater and cooling source. The heaters can be switched on or off individually by the middle switches, which interrupt the output to the coils on the relays. Although this isn't necessary, I figured there would be times when I would want to have the heaters off when I have the door open and it avoids having to go through several steps to turn it off on the PID. Interrupting the coil output seemed to be the easiest way to do this. For general air circulation in the chambers, I installed some door mountable fans from home depot. They have individual switches and are controlled by a cycle timer from Rammeter.com and a 1.5 amp fan controller. I also installed a fan controller to the upper chamber cooling fan to allow more fine tuning of the system. The covered switch on the left side of the panel is the main power switch. I covered the vents with 240 volt outlet plates and some heavy duty screen I got from home depot.

 

[Mtn_Brewer]

Technically, I think making the doors was the toughest part. When I paneled the front of the fermenter, I measured and marked the doors with meticulous detail. I cut them out using a circular saw carefully so I could use the inserts in the actual doors. I used 1 x 4's that I glued in place with some strong wood glue and then secured with short screws from behind. I hung the doors to get the right places for the screws and hinges and get the latches worked out. The 1 x 4's didn't leave enough of a gap for the weather stripping, so I attached a 1/4 x 4 inch board over the top of the hinge and latch blocks. This left just the right amount of gap for the weather stripping. I took them down and framed the back with 2 x 3's and insulated them with foam board. I think the R value is 7.5. Through trial and error, I figured out that I needed to cut the right side of the 2 x 3 framing at a 15 degree angle so it would close without hitting the door frame. I paneled it with 1/4 inch plywood then filled in all the gaps with wood filler. Once it was dry, I used an angle grinder to even up the plywood with the 2 x 3's and then painted them.

 

[Mtn_Brewer]

I sealed the doors with some weather stripping from home depot. I kept the two strips connected to get a double seal. I cut a 1/4 inch slice out of the inside strip to allow it to navigate the corners. I used 1/4 inch staples to secure the stripping. I had to use a hammer to flatten the female part of the latches (~1 mm) to get just the right seal.

 

[Mtn_Brewer]

I used K type thermocouples as sensors. I got them from Auber instruments. They are meant to be used in air inside kilns, so I just hung them from eye screws in the corners. In my chest freezer, I never submerged my probe or used a thrmowell, so I figured this would work for this chamber as well. I used a location where neither the heater or AC/cooling fan would blow directly on the probe.

 

[Mtn_Brewer]

I made a DIY chalk board for the front out of a piece of galvaized sheet metal I had left over from my hood build(https://www.homebrewtalk.com/f51/diy-garage-hood-heat-shield-375755/), a can of chalkboard spray paint and a 12 x 36 inch frame. This way I can easily keep track of fermentation schedules and gravity readings. As a finishing touch, I added the metal Racer X sign. For those of you not old enough to remember the old Speed Racer cartoons, I suggest you look it up on youtube.

 

[max384]

Wow. Excellent build! How cold can you get the chambers with that AC unit?

 

[Mtn_Brewer]

I almost forgot...a word about AC unit choice.

I bought an LG LW5012J AC unit from Home Depot for ~ $100. I knew I was going to have to do something to get down to lager temps, as the thermostat (like all AC units) would not cool below 50 degrees. I knew I couldn't do the trick of pulling the temp probe outside of the chamber, because my garage frequently is between 40-50 degrees, so I couldn't get to my usual lagering temps. I took apart the front of the unit, as shown, thinking I was going to have to find some way to bypass the thermostat. Fortunately, I discovered this screw on the side of thermostat that I figured out was the tuning screw. By turning it ~ 10 turns to the left, I completely turned off the temp governor. I sealed the unit into a small plastic container and found I could get the temp down to 10 degrees! I was therefore able to put the whole unit back together again without any DIY mucking around.

 

[chipsah]

Damn it. I am trying to keep the garage in my new house as a sleeping place for my Jeep. Then, you go and post something like this and I think, "I gotta have one of those."

Really, great job. It's beautiful. Craftsmanship appears to be top notch.

 

[Mtn_Brewer]

Admittedly, I haven't actually used it as a fermenter yet, but I've played around with the temps and it can hold a steady temp with a hysteresis band of 2 degrees. It's insulated well enough that the AC and/or heater don't have to cycle very often at all. Given the volume of the chamber, the 500 watt heater doesn't appear to be overkill at all. Overall, I m pleased with how it all turned out and I certainly lerned a lot along the way.

So there it is. I hope you all find this interesting and gives you some ideas. I'm anxious to see what upgrades others come up with.

As this style of fermenter doesn't appear to have a name, I will throw out the name "two-tier fermenter". It's easy to say and is accuratively descriptive IMHO.

 

[Dave37]

A truly great job. And an awesome work space by the way. If you brew as meticulously as you organize and build then I must say I'd like to try a mountain brew or two some day.

Cheers

Dave

 

[Mtn_Brewer]

Wow. Excellent build! How cold can you get the chambers with that AC unit?

While messing around with it yesterday I got the temp down to the mid 20's in the lower chamber. This was only for a few minutes though. I suspect if I tried to use it as a freeer that the coils would ice up. I usually lager at 36-40 degrees, so I think I'm safe.

 

[Mtn_Brewer]

A truly great job. And an awesome work space by the way. If you brew as meticulously as you organize and build then I must say I'd like to try a mountain brew or two some day.

Cheers

Dave

My theory is that OCD is only a disorder if you don't know how to channel it.

 

[Ryush806]

Awesome build! Let us know how it works with some fermentations going!

Also, if you don't mind me asking, about how much did that cost to put together?

 

[emjay]

My theory is that OCD is only a disorder if you don't know how to channel it.

By definition, it needs to result in substantial impairment in one's social, work, and/or academic life in order to be considered a disorder of any clinical significance. In other words, if it's something you are able to "channel" or to otherwise benefit positively from, it's not OCD.

 

[Mtn_Brewer]

By definition, it needs to result in substantial impairment in one's social, work, and/or academic life in order to be considered a disorder of any clinical significance. In other words, if it's something you are able to "channel" or to otherwise benefit positively from, it's not OCD.

I most definitely agree with you. I didn't mean to make light of a potentially serious mental health condition. If I offended you or others, I appologize. I realize I should have phrased my quote differently and given some back story. When Dave37 commented on my fastidious work, it reminded me of how my SWMBO often diagnoses me with having OCD when I get into projecting. When she gets annoyed I use the line about channeling OCD and remind her how much she actually likes the beer I brew, the trellises I've made, etc and she usually gives me a nod of agreement and then tells me I've got 30 minutes to clean things up. I'm sure others can relate.

 

[Mtn_Brewer]

Awesome build! Let us know how it works with some fermentations going!

Also, if you don't mind me asking, about how much did that cost to put together?

I didn't keep an accurate tally but I'd estimate it was about $1,200. This includes ~$200 that was spent on experimenting and screw ups. It wasn't cheap, but it is exactly what I wanted and should last for decades.

 

[Ryush806]

I didn't keep an accurate tally but I'd estimate it was about $1,200. This includes ~$200 that was spent on experimenting and screw ups. It wasn't cheap, but it is exactly what I wanted and should last for decades.

For sure! Probably on par or maybe cheaper than buying and modifying two big chest freezers and definitely a lot nicer!

 

[Mtn_Brewer]

For sure! Probably on par or maybe cheaper than buying and modifying two big chest freezers and definitely a lot nicer!

The other advantage is that I made the dimensions so I could fit and access 2 Blichmann 14.5 gal conicals in each chamber, should I decide to go that direction. It's not so easy to use conicals with a chest freezer.

 

[blakelyc]

This is awesome!!! I have a potentially silly question, though. Whenever I see these types of things they are usually cool-only. Is it not ever necessary to provide a heat source as well?

 

[Mtn_Brewer]

This is awesome!!! I have a potentially silly question, though. Whenever I see these types of things they are usually cool-only. Is it not ever necessary to provide a heat source as well?

Go back to the 6th post of the thread. The black boxes are the Broan 120 wall heaters. The Auber PID I used includes easy instructions on how to control both heat and cooling. Essentially, the main controller is set to cool and the low temp alarm output gets connected to the heater. Each has its own hysteresis band, so you basically dial in a high and low range. Given that my garage is only heated on demand and has no cooling, I'm sure I will need both functions given the hot summers and cold winters we get in Colorado.

 

[blakelyc]

Ah, I have no idea how I missed that. My own fermentation system will go in my basement in an area that is semi-conditioned, so I am debating a heater at all.