DIY Glycol Chiller build

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Mcbobs

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After a year of burning ice like crazy for recirculating ice water through my unitank's chilling coil, I decided it was finally time to look into a glycol solution for maintaining fermentation temps. Looking at all of the different commercial options and realizing that I really didn't want to spend $800-1000 for glycol, I decided a DIY approach was more my style.

Looking around online, there really wasn't much information on how to get a homebrewed glycol system going, but I was able to find just enough info to get things started. I learned a lot while building my system and thought sharing what I did might be beneficial to someone else looking to get a glycol chiller going.

For anyone else looking to add a diy glycol chiller to their equipment, hopefully my build journal will help you out!

https://ornatebrewingco.com/2020/01/12/my-diy-glycol-chiller/
 

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I know this thread is a bit old, but the responses on your site page were pretty recent. You document everything well, thank you for that! It looks like an amazing build!

I have been going through ice fast when I am doing a 5G fermentation (40-60# per), and I am adding two more 5G fermentors, so being able to maintain temps on all three at the same time is necessary. I don't want to go through that much ice (much less move the melt water), so glycol it is!

I am planning to build my glycol chiller in the next couple of weeks, just assembling the parts now. I have a cooler I have been using already, so I should be able to adapt it for an A/C unit (5K) and three separate cooling systems through the lid. I have the extra ink bird to run the A/C, so I think all I need now is the A/C unit, a recirculating pump for the glycol, and the glycol itself. I haven't decided if I want to box in the A/C as you did, or just let it hang out in the garage. With the filter screens in your box, does your A/C pick up a lot of dust? The glycol should be sealed inside the cooler and dust-free.

Am I missing anything?

On a related topic, do you worry about air ingress in the fermentor when you cold-crash? I can see this being the next step in my process, if it is an issue.
 

Tallgrass

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Are you making 15 gallon batches or 3 different 5 gallon batches at different stages of fermentation? If you're going to run three separate cooling circuits each will need its own pump and inkbird. Unless I'm missing something in which case I hope someone chimes in with a better solution.

My chiller lives in the basement and dust isn't an issue but an enclosure sure would make it look nice. Id rather just let it breathe.
Your cooling fluid should be sealed from from air to prevent evaporation and therefore dust free. I use water but that creates problems like rust and a drain and clean every couple months. I use my chiller for post boil chilling and fermentation temp control /crashing. Spills happen when moving pipes around and I'll just deal with the rust and cleaning as opposed to glycol cleanup. At a 34f cooler temp it does require a separate pump directed at the condenser to prevent ice build up.

You do have to worry about air ingress during cold crash. How you deal with that would be fermenter dependent. With my 60l spiedel fermenter I just give it a few pounds of co2 pressure and check every day with a squeeze. I have the parts for a gauge but haven't installed it yet.
 
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I make 5G batches, but I also make cider, wine, and mead. So I am going to have one cooling control & pump for the A/C, and three independent, one for each fermenter. I am looking also at the draw each makes, no desire to flip a breaker when cooling three ferments at the same time.
 

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Are you making 15 gallon batches or 3 different 5 gallon batches at different stages of fermentation? If you're going to run three separate cooling circuits each will need its own pump and inkbird. Unless I'm missing something in which case I hope someone chimes in with a better solution.

My chiller lives in the basement and dust isn't an issue but an enclosure sure would make it look nice. Id rather just let it breathe.
Your cooling fluid should be sealed from from air to prevent evaporation and therefore dust free. I use water but that creates problems like rust and a drain and clean every couple months. I use my chiller for post boil chilling and fermentation temp control /crashing. Spills happen when moving pipes around and I'll just deal with the rust and cleaning as opposed to glycol cleanup. At a 34f cooler temp it does require a separate pump directed at the condenser to prevent ice build up.

You do have to worry about air ingress during cold crash. How you deal with that would be fermenter dependent. With my 60l spiedel fermenter I just give it a few pounds of co2 pressure and check every day with a squeeze. I have the parts for a gauge but haven't installed it yet.
I'm just starting to read about these DIY glycol systems and don't know much about the specifics involved but I may have some input on the three pumps. While it might seem an opposite example, I rebuilt my hot water radiator heating system in my house from whole house to 4 separate zones. One way to do that was with 4 pumps, effectively making four smaller branches similar to the original. My original pump was still good and certainly large enough. Another way to make it work is to have the electric furnace deliver hot water to the pump and then split to four zone valves, each valve is linked to a separate thermostat. Hot water goes through the valve to the radiators in that zone and returns to the furnace. There is an intermediary part of the system, the zone valve controller, which receives the call for heat from all the thermostats and it tells the furnace to turn on and which zone valve(s) to open. There's also a check valve at the end of each zone to keep the water going one way. So the difference is each zone in my system has a zone valve not a separate pump. For heating, you probably still need a check valve on the zone end regardless. I don't know with a multiple pump system what is used to control the pumps and furnace, that is, what acts like the zone valve controller. There are if ciyrse variations to systems, I started with a functioning furnace and pump, but my furnace electronics are late 90's. I think in my case cost is somewhat of a wash initially but I think it's easier to replace a zone valve than a pump and a little cheaper on a unit basis.

Long answer but I think you could build three zones with potentially one pump. I didn't quite understand the condenser issue but potentially that could be an extra zone. As far as whether it would be cheaper to emulate my heating system, I'm not sure. The pumps you might use off the shelf might be cheaper than a zone valve.

What size tubing is commonly used for glycol systems? Shorter zone runs than a house too.
 
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This is intriguing. I would need to check my local electric parts store to see about automated flow control valves, but then 1 pump and 3 flow control valves with three temp probes/controllers would work. Anyone ever do this before?
 

Deadalus

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Not wanting to lead you down the wrong path I did a little searching because it was a couple of years ago that I rebuilt my heating system. The zoning that you are interested in is similar to a zoned hydronic heating system.

Mainly focus on the upper half, there are separate zone circulators controlled by the multi-zone relay center. That relay center receives information from the thermostats and then fires the boiler and in added complexity also works with the water heater for hot water in the plumbing system.
1620317788895.png

vs using zone control valves. Zone control valves (number 3) and a zone controller @1 (green). The zone controller is basically a fancy switch that receives the thermostat information. Basically, you have multiple thermostats where any one may need to turn on the boiler/furnace. [Note, the water heater is not integral to these two diagrams but potentially could represent the glycol reservoir. My water heater is separate in my system so I am not sure about how that part works in these diagrams.] Pump is @2.
1620318282888.png

If I read correctly, the OP's system uses a temperature controller to keep the glycol at 25F with a submersible pump and then a separate temperature controller on the fermenter which operates a fermenter pump. A boiler or furnace has what I think is called an aquastat that is equivalent to the temperature controller on the air conditioner and glycol pump.

Two well known companies for zone control valves are Honeywell and Taco. From what I saw, a zone control valve runs upwards of $65 in the heating world. I think they are generally 24V which is another function of the zone valve controller. There's probably other applications in industry for electronic control valves, but I think electrical supply house would send you to plumbing and heating supply. I like supplyhouse.com myself. The pumps one might use here are likely less than $65 but likely lacking a bit in quality. Certainly a plentitude of other options in the heating and cooling world. I'm not a heating or AC person, I just recognized the problem as similar to what I had encountered in my home heating rebuild.
 

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Here's how a guy by the name of Colorado Boy does it commercially with a single pump. In essence, it's done with a manifold loop, controllers and some valves. Overall it's really pretty simple.

 

Deadalus

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The one issue about controlling it with a single pump is that you would have to leave the pump on all the time in the simplest design with the assumption that a pump needs to be on while the AC unit is on. You could repurpose the pump in the glycol reservoir to run the loop but it would need to stay on and not be temperature controlled. With the AC unit controlled by temperature, there will be times it is off but the pump would need to run in a single pump system when the fermenter needs cold.

A submersible pump costs about the same as a 110V solenoid valve. (That valve would need a plug for the temperature controller.) This is assuming there is a need for the AC pump, you would need two pumps and three valves for a 3 zone system or you would need four pumps for the 3 zone system. The difference is 3 valves vs 2 pumps.

In order to have the pump come on when cold is called from a fermenter, something like the zone valve controller would be needed for the zone valve system. The zone valve controllers run about $100, I think it has a 24V transformer, which appears to be more commonly used for the zone valves and solenoids, plus the thermostats are 24V. Something simpler would be a switch that when it receives a signal for on from any one of multiple sources, it turns on the device. That's what is built into the zone valve controller, potentially not a very complicated item but I don't know what it is. Kind of like a three way or four way switch but the logic is different.
 
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Deadalus

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It's an "end switch" inside the zone valve controller that turns on the circulator. This is my controller for the heat. I'm not good with wiring schematics other than put the wires here, here, and here.
 
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I am going to try to write this out to understand this better. Please correct me if I am wrong:

A. If the pump in the glycol's purpose is to keep the A/C unit from icing up, it only needs to run and circulate while the A/C is on (at least this is what I understood from other posts on the topic). So the Inkbird (or equivalent) would only turn the A/C+pump combo on when the glycol gets too warm. This system works independent from the pump(s) for the fermenter(s).

B. As for the pump system for the fermenter(s). Each fermenter has it's own temperature controller and thermometer. The options here appear to be:
1. have an individual pump for each fermenter that runs off of that fermenter's individual temperature system, or
2. have one pump that turns on when any of the temperature controllers turn it on-this also requires automatic on/off flow valves/solenoids for each fermenter that open/close at the command of the temperature controller for that fermenter, or
3. have one pump that always runs (like the youtube video above) and flow valves/solenoids that open/close and thereby redirect the flow of cold glycol to the appropriate space, as controlled by the individual temperature controllers. I believe this pump could also serve the purpose of keeping the glycol flowing and de-iced, thereby eliminating (A) above, but it would be running 24/7.

It would seem that:
#2 requires a level of electrical engineering/programming that I think is beyond me at this time.
#3 seems electrically wasteful (and stressful to the pump) unless there is a constant flow of fermenting beer, cold crashing, and/or lagering in the fermenter. This sounds easier than #2, but still requires a bit of engineering.
#1 seems the simplest and most cost-effective solution for my three 5-Gallon fermenters (or carboys, as the cooling system I use fits a bucket/conical or a standard glass carboy).

Rational or crazy?
 
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It's an "end switch" inside the zone valve controller that turns on the circulator. This is my controller for the heat. I'm not good with wiring schematics other than put the wires here, here, and here.
This is fascinating and helpful. So instead of heating, it's cooling. And Taco makes all of the parts to accomplish the flow control and such?
 

Deadalus

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I am going to try to write this out to understand this better. Please correct me if I am wrong:

A. If the pump in the glycol's purpose is to keep the A/C unit from icing up, it only needs to run and circulate while the A/C is on (at least this is what I understood from other posts on the topic). So the Inkbird (or equivalent) would only turn the A/C+pump combo on when the glycol gets too warm. This system works independent from the pump(s) for the fermenter(s).

B. As for the pump system for the fermenter(s). Each fermenter has it's own temperature controller and thermometer. The options here appear to be:
1. have an individual pump for each fermenter that runs off of that fermenter's individual temperature system, or
2. have one pump that turns on when any of the temperature controllers turn it on-this also requires automatic on/off flow valves/solenoids for each fermenter that open/close at the command of the temperature controller for that fermenter, or
3. have one pump that always runs (like the youtube video above) and flow valves/solenoids that open/close and thereby redirect the flow of cold glycol to the appropriate space, as controlled by the individual temperature controllers. I believe this pump could also serve the purpose of keeping the glycol flowing and de-iced, thereby eliminating (A) above, but it would be running 24/7.

It would seem that:
#2 requires a level of electrical engineering/programming that I think is beyond me at this time.
#3 seems electrically wasteful (and stressful to the pump) unless there is a constant flow of fermenting beer, cold crashing, and/or lagering in the fermenter. This sounds easier than #2, but still requires a bit of engineering.
#1 seems the simplest and most cost-effective solution for my three 5-Gallon fermenters (or carboys, as the cooling system I use fits a bucket/conical or a standard glass carboy).

Rational or crazy?
A. Yes.
1. Yes.
2. Yes.
3. Yes, you could configure the return port to flow post the AC coils much like a whirlpool port.

#2 It required some study on my part for me to figure out my heating system. It was challenging and ultimately saved me a lot of money in my house but it might not be worth the ~$20 for this application. Engaging for me because I could apply what I learned (and mostly forgot!)

#3 It's electrically wasteful but those pumps are made for aquariums and fountains so perhaps not a big deal mechanically but sure it would wear it down prematurely. Sometimes though it's the on/off that kills the product.

#1 I agree.

So the end switch isn't doing what I was thinking. It's just a delay that gives the the valve time to fully open then the pump activates. It seems that what the zone valve controller is doing is simply like having switches wired in parallel for a single light. Any switch turns it on but all switches have to be off to cut the power. DON'T ANYBODY DO THE FOLLOWING WITHOUT TALKING TO SOMEBODY ACTUALLY QUALIFIED LIKE A REAL ELECTRICIAN OR ELECTRICAL ENGINEER. I think it would be the same as having an extension cord with three male ends and one female end plugged into the the three temperature controllers while on the same branch circuit. The temperature controllers are switches.
 

Deadalus

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This is fascinating and helpful. So instead of heating, it's cooling. And Taco makes all of the parts to accomplish the flow control and such?
I'm not sure if Taco manufactures pumps but they make the zone valves and the controller. My pump is a Bell and Gossett 100, it's kind of a standard workhorse. Thing I didn't quite recall though is that the thermostats are low voltage (24V) coming into the zone valve controller. But I was wondering if perhaps a different sensor would work like on my EHERMS. That feeds into a PID though and those are more expensive than the usual Inkbirds. Now here's a cheaper temperature controller that's very basic with no step functioning that would work on the AC unit. There's a similarly designed Inkbird but it didn't have the temp sensor with it.
20210506_173758.jpg
 
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I wanted to thank you very much for all of the effort you have put into this thread, because I'm learning a ton.

Oh, and "Not Now, John." Excellent taste in music.

If you like ciders, sours, barley wine, or imperial stout; that's what I have in bottles. PM me an address, I would love to send you a box of "yeast samples."
 

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