For those that asked about my custom built a/c chiller

So a year or two ago I was inquiring about hvac help, as I was building a diy chiller for my rotovap and other projects. People have been since asking for pics and details and finally got around to it. So here goes. Note; I’m no where near as smart as you guys so I can’t break down cooling power etc.

This set up brings a 55 gallon drum of glycol down to -25c in about 3 hours. Once chilled, I can run my 5l BVV r1005 rotovap non stop, and it never goes under -22c. Roto heat bath is set at 114f. I believe this can probably handle a much bigger load or rotovap, but alas, I’m no smarty. Cool thing is with so much insulation, once I shut things down. This thing barely loses and temp even over a week. I left it unused once for almost 2 weeks, and the temp of the glycol was still in the negatives.

I don’t have a ton of build pics, but the build itself is pretty self explanatory.

Materials-
—Used 30,000 btu window ac- $300
—2 sheets plywood- I had, but pretty cheap
—About 10 bags of that foam insulation that comes as liquid in a bag, you pop a seam, mix the 2 fluids in the bag and it starts turning into foam. Very simple.
—55 gallon plastic drum
—55 gallons of glycol
—cheap submersible pond pump

The build is simple as seen in pics. I simply built a plywood box that can hold the 55 gallon drum, with ample room around it for insulation. I then built a second box/shelf to hood the ac up high.
Here comes the ONLY complicated part. The idea is to submerge the radiator of the ac in the liquid. On a smaller scale you can slowly bend the pipes to get the radiator to sit in a cooler or tub. For this, I found and paid an hvac guy to simply drain the coolant from the ac lines, cut the line attached to the radiator, plumbed a new pipe going into the barrel, and reattached the radiator in a way that it’s submerged inside the barrel. Then he recharged the lines with coolant.

Filled the barrel with glycol, submerged a cheap pond pump in it, and ran 2 vinyl hoses coming out of it for my in and out flow.

That’s about it. My build details probably aren’t the best, but just looking at the pics you can see exactly what I did. As I said the only rough part was having to re-plumb the ac pipe going to the radiator so I can submerge it in the barrel. That cost 200. It’s been great not relying on the piece of shit chiller they give you with “turn key” systems. Any questions feel free to ask! I think for about 500$ (and can probably do cheaper) this was a great solution for my recovery. I kind of want to test it on other things like cooling solvent tanks and stuff.

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Nice build! Thanks for posting the pics and directions.

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Thanks! Like I said, not the most detailed but it’s mostly self explanatory. Having to replumb the pipes for the radiator is the hardest part and needed a pro. Definitely beats spending thousands for a chiller to run my rotovap. Curious to see what other loads it could handle

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Very cool. I just built a smaller one about a week ago.

For cooling the etoh, you could put another pump in the glycol and pump it through a wort placed in your ethanol. May take a while that way, but in my opinion it’s easier then pumping the ethanol.

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No lie… never thought of doing that for my etho runs. I currently run my etho out of a 0 degree freezer through 2 worts in dry ice slurrys to get it down to -60 if I can… I wonder if running it through a big wort in the glycol first would require less dry ice to get it that cold. I also kind of want to plumb it into a solvent tank and see how cool I can keep my butane tank since I wasn’t chilling it at all before, just running my recovered vapor through dry ice slurrys and coils.

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could one put a plate chiller in the glycol to pre-cool eth for extraction?

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I gotta say, this is an amazing setup. Wish I would have done this vs spending thousands on a machine. Love the foam and barrel. And the casters. Nice job. :+1:

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Currently using it right now… been rotovapping all day long and it’s sitting at -22c

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I actually recently thought about putting a coil in there to pre chill my etho before sending it through my dry ice slurried coils. 55 gallons of -22c liquid offers quite the heat sink. My etho comes out of steel kegs in a 0 degree chest freezer. After 2 coils in dry ice slurries I get to about -50 — -60c. Using the ac chiller to bring it down to -20 before it even goes through the slurry coils would probably help

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So a comment that the infamous @Pupparoo made brought me here. As a former hvac guy , I’d like to ask if anyone has hacked a mini split to make a chiller?
The compressor modulation could lead to colder temps than a traditional unit.
Im interested and I may hack a unit for science.

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Doooo it

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How much colder?

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Thats the question I have also. I assume much colder, but there is only one way to find out. I will find a used unit that I can chop up and do some experiments.

This guy beat me to it.

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He don’t tell us how to do it tho. Make a tutorial for us @TheGreenDotStore

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Always liked this post figured it fits here

http://www.jonolavsakvarium.com/eng_diy/chiller/chiller.html

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I have a 2 ton unit ready to attempt this on what’s up with a tutorial

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@TheGreenDotStore Need to find one big/cold enough to keep up with hydrocarbon shotgun condenser recovery and take your member of the month like a champ!

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Need more hp than a mini split to keep up with the shotgun all day.

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Set high goals man. Lol

What’s the cheapest route at the moment to run a 3 inch shotty?

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