A/C glycol chiller w/ two 14 gal SS Brewtech conicals

[Tiber_Brew]

I've seen a few DIY glycol chillers made from window A/C units, so this isn't anything entirely new. Thought I'd share my build, and how I integrated it with my system with two new 14 gallon SS Brewtech conical fermentors. I finished this project last winter, and it has worked very well for me so far.

Finished project:

How it works: the evaporator from the A/C unit is submerged in a glycol solution inside a small cooler and is controlled by a PID unit in ON/OFF cooling mode. I chose one that has anti-short cycle delay to protect the compressor. The glycol PID gets temperature data from an RTD in the glycol solution. There are two submersible pond pumps - one for each fermentor - that are each controlled by a PID in ON/OFF mode. Temperature data is sent via RTDs in the thermowell on the conicals. When the beer reaches a certain temperature (SV+Hy), the PID turns on the pump, which pumps ~19F glycol solution through a coil in the fermentor, and back into the cooler. When the glycol temperature reaches upper control limit, the PID turns on the compressor/fan and cools the solution as needed.

I also opted to include a 120VAC switched outlet on the panel for a CIP pump. With that, I can do all the CIP & SIP required for the conicals without having to use an extension cord or have a separate switch box - it's all in the fermentation control panel!

A big shout out to Ryan at eBrewSupply for his help. He was generous with sharing his knowledge, wiring the panel, and helping me acquire some equipment.

I started with a 5,000 BTU window A/C unit. Got it for about $130 at Sears.

Then tear it down and discard any unused parts:

Carefully extend the evaporator into the cooler. You don't want to stress or kink the copper lines. I used a 34 quart cooler, which will be filled to about 5.5 gallons of glycol solution.

Next bypass the OEM thermostat and remove that. Make sure loose components are secured:

Cut off the GFI power cord that comes with the unit and save that for the control panel, then wire a new power cord for the A/C unit with a twist lock style connector. Also cut the standard connector off the pumps and replace with same twist style connector:

Meanwhile I modeled up a design for a control panel in CAD and sourced the materials through ebrewsupply. Ryan came up with the wiring schematic that would best fit my needs.

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[shadow160]

The pics are not showing.

 

[Tiber_Brew]

...continued

I wanted to build a basic box to contain the chiller unit and keep some of the noise down. I started with a model and drawing:

Then get to cutting:

Apply a couple coats of paint:

Modify the cooler for the glycol in/outlets and recess the rim for a flush fit of the evaporator lines and wires:

I put a screen on the box's front opening for the A/C fan to keep critters out. There are several holes on the side panel to allow air in the box to keep the condenser cooled. I also added acoustic foam on the inside panels to help dampen noise.

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[IslandLizard]

Sounds great... but Photobucket ain't your friend anymore.

[Update]
OK, they show up now with the different image hoster.

Great project, man!

 

[Tiber_Brew]

The box starts coming together...

I used leak-stop quick disconnect fittings so that I can pull the box away from the setup without draining all the glycol in the lines. I got the idea from another thread in HBT. Pretty slick.

While the chiller box is coming together, I got some new stainless...

Meanwhile I cut and painted some boards to mount the plumbing on the wall:

I used pex for the wall mounted plumbing:

Upgraded from camlocks to TC fittings:

After a thorough cleaning, I attached a heating pad I used to use for my carboys to the conicals. This way I can ramp up the temperature the way I want regardless of ambient temps. I use the PID controller box I built for my old carboy configuration.

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[Tiber_Brew]

I'm working on fixing the image host... bear with me

 

[Tiber_Brew]

Are the images showing up now? I'll continue posting tomorrow or sometime early this week. There are a lot more pics to show.

 

[shadow160]

Yes they are working, looks like a sweet project.

 

[MilkStout]

Looks great. Nice job. Would you mind sharing the wiring diagram?

 

[Mordhaus]

Looks great. Following.

 

[milldoggy]

You have a wire diagram of the chiller panel? Been thinking about doing that. I already use a chiller for my tap lines. Been nice to extend that to conical chiller.

 

[Tiber_Brew]

...continued


Neoprene jacket is on. The power cord and thermocouple for the heating pad come out of the opening for the legs in the jacket. The port you're seeing is for the cooling coil.

Determining hose length from the conical to the hard lines. I used leak-stop quick disconnects again here. For this stretch of plumbing I used automotive grade insulated silicone tubing - another idea I got from an HBT thread here.

CIP spray ball from brewershardware.com and 3" TC piece I put together for pressurizing the fermentor with CO2 for crashing and transfers that also fits on the top TC ferrule. I'm told that SS Brewtech now offers the 3" TC x 1/2" NPT with a PRV, which I would've gotten had they been available at the time. I monitor the pressure on the regulator feeding the fermentor carefully to make sure I don't exceed the recommended 2psi limit, but a PRV would be nice insurance to avoid damaging an expensive hunk of stainless steel.

Water testing the fermentors and CIP spray ball:

Cleaning more fittings:

First fermentor assembled and hooked up to the glycol plumbing. Progress on the box is stagnant at this point until the control panel is finished:

Continued...

 

[Tiber_Brew]

...continued


Fun day at the ebrewsupply shop. He's really set up well and knows his stuff, so this went relatively easily. I supplied the CAD generated .dxf files and he got his CNC to do the rest.

He then printed my text layout on the panel cover with his laser etcher, and afterward I started populating components. Starting to look like something...

Adding more hardware:

Soldering receptacles:

Then began the wiring. Ryan is a hundred times faster at this than I, and the schematic was more or less in his head anyway, so best to let let the wizard work his magic:

Before I could finish my beer, the panel was complete:

Then I cut and painted some 2x4 to mount the panel to the wall:

With the control panel finished and mounted, I could feed the cables through the last wall of the box and get that finalized. I used trimmed pieces of pipe insulation to secure the wire through the holes that the connectors had to fit through. If I would've expanded my budget, I would've done this differently and installed a small connector panel on the side of the box where I could plug/unplug each cable from the box itself. It's not too late to upgrade in the future...

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[Tiber_Brew]

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I then assembled the fermentor RTD cables:

Finishing the glycol system:

Time to integrate everything:

I chose a 34% Propylene Glycol / distilled water ratio based on the temperature I needed. Handy guide found here.

Testing the plumbing for leaks and the glycol pumps controls for functionality:

Glycol RTD added (I've since replaced this with the same IP67 rated RTDs used for the conicals, though I don't have a pic):

A shot of the chiller box with the lid off. I wrote the ratio and amounts of water and glycol on the cooler lid for future reference:

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[Tiber_Brew]

More preliminary testing of the panel. The glycol PID and parameters shown here were temporary; currently installed is the Auber SWA-2441, which is the only 1/16 DIN PID that I've found that has anti-short cycle delay for compressors.

Hooking up the second conical put together in the same way (including embedded heating pad) as the first:

Starting to wrap up the build:

Some more cleaning and passivation:

And a new stainless work top for lab work etc.

Everything is set and ready, so the first couple batches of beer are brewed and fermenting:

Getting ready to dump the trub:

Come time to cold crash and lager, using my CO2 adapter to maintain positive pressure in the fermentor:

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[Tiber_Brew]

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Kegging:

The mess left behind after fermentation. Nothing some 150F PBW solution and a CIP spray ball can't take care of.

Fruits of my labor: a low oxygen German Helles. Squeaky clean and delicious!

Cheers!

 

[milldoggy]

Nice find on the auber with a compressor delay. Nice to match the brew panel

Awesome work, will be stealing some of your ideas once I can find the time

 

[Tiber_Brew]

Nice find on the auber with a compressor delay. Nice to match the brew panel

Awesome work, will be stealing some of your ideas once I can find the time

Thanks!

I was a bit surprised that it was the only 1/16 DIN PID I could find with ASD capability.

 

[SleepyCreekBrews]

Nice work boss.
...looks like the wall painter didn't show up on time tho , eh ?

 

[Tiber_Brew]

Nice work boss.
...looks like the wall painter didn't show up on time tho , eh ?

I know, I know...looks like crap. Plan is to put up FRP at some point. I also said I was going to get my brew stand powder coated and that was 7 years ago!

 

[tigerbalm2424]

How are you controlling the heater pads when you need to increase temp of conical?

 

[Tiber_Brew]

How are you controlling the heater pads when you need to increase temp of conical?

I built a separate 2-PID controller that switches the heating pads. The PIDs are set to on/off mode with a 1F hysteresis.

 

[tigerbalm2424]

Thank you very much. I am trying to mimic your setup. What fittings were used to go through the cooler wall for the glycol lines?

 

[Tiber_Brew]

Thank you very much. I am trying to mimic your setup. What fittings were used to go through the cooler wall for the glycol lines?

Those are just straight through bulkhead fittings with a 1/2" barb on either end of the coupler. I got those and similar fittings from bargainfittings.com.

 

[carpenike]

Nice! Where did you get the leak stop quick disconnects from?

 

[Tiber_Brew]

Nice! Where did you get the leak stop quick disconnects from?

I got those from usplastic.com

 

[pughww]

Great looking set-up! Where did you source your heating pads?
Thanks, Brian.

 

[Tiber_Brew]

Great looking set-up! Where did you source your heating pads?
Thanks, Brian.

Thanks!

You used to be able to get them via Midwest Supplies or Northern Brewer, but it looks like they don't sell those anymore. If you search for "fermentor heating pads" or something similar, you might find something that works.

 

[jcav]

Outstanding thread and build!

John

 

[Tiber_Brew]

Outstanding thread and build!

John

Thank you!