Suggestions for diy glycol chiller fluid?

Your Absolute best efficiency is going to be with the lowest amount of glycol to water you can manage and still achieve your lowest temperature without turning to slush and affecting your pumpability.

Pre-mixed 50-50 Should get you close enough

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Thanks ! I’m gonna make a post documenting my chiller build for the children of the future

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Tractor supply stores carry pg by the gallon for 20$

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At 40-50 gallons, that will break the bank. Gonna look into that splash antifreeze it’s under $250 for a barrel

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Yah anywhere making biodiesel often creates glycol as a byproduct of manufacturing. If you’re lucky enough to have a maker nearby, you might be able to get a barrel for like $50 or something. They don’t usually have a use for it I find.

I’ve made 4 of these chillers so far. Just picked up another one. My ultimate goal is a Venturi vacuum pump coupled into the system :smiley: well see if I manage.

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Did you say “maker” ?!?

:face_with_monocle:

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Nice!

Please can you share your build on this

I thought I had

started with a window AC unit that I found in my junk pile. One that had been out to burning man, lived in Gerlach NV for a couple of years, then found it’s way to OR in a buddies bus.

all I did was remove the case, and rotate the cold side heat exchanger into a $5 cooler from St Vinnie’s. I had to sit the unit on something to make that work (I think I paid another $5 for the crate) .

I secured the crate to the cooler with a ratchet strap, and put wheels under that so it moved as a unit (having interacted with one of @tweedledew’s creations that did not move as a unit). and used carboard, a bike inner tube, and some bits from the original cover to make it harder for folks to get their hands into the fan. with coolant I believe it ran me less than $15. ran the 2l Bucci rotovap I had on it just fine.

I might have build pictures on this or another unit on my phone somewhere. I might even find time to upload at some point.

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I will try and find pictures or take new ones and upload my project. It actually works incredibly well getting to well below -20, and after I turn it off the insulation keeps that temperature for days it’s kind of crazy. Basically the parts were simply a large used window air conditioner, and a 55 gallon drum of chiller fluid. I build a box around the barrel filled it with foam insulation and had an HVAC guy cut the pipe on the air conditioner and extend it to the radiator So the radiator can sit inside the barrel. Honestly it was a super easy project and considering it can keep up with my rotovap all day long I consider it a win

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Honestly, provided compliancy isn’t your aim. Paying $150 for a chiller is way better than $2500 for the same end results lol

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I researched the chillers I would need for my purposes and I did indeed save thousands of dollars by building this myself. It’s a little bulky, but like I said I save thousands of dollars to achieve what I needed so I’ll be glad to help others

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different build.
before any attempt to keep fingers out of the fan(s) or electronics were made.

I don’t seem to have pictures of either of the builds where the AC unit is mounted ON the cooler, although it’s likely that this was one of them, and I rotated things by 900 after this picture was taken.

this one started with a brand new $150 window AC unit. build time about 60min.

I’m not known for being gentle on these things. I generally just nail the compressor in the ON position…there are other solutions.

I didn’t build this one, but I did bundle it up so it could be moved around the lab, and used bits salvaged from another build to make it a hair safer to interact with. I’m not sure it I wired the inkbird thermostat in or not. it looks like my work :wink:

label reads “Safety Third!”

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I was just thinking of an idea for heat,
Servers would be an amazing resource for recycling energy if one could rig a system together.

You should make a DIY video with a donation link. A couple of those ones you built me were works of art!

An mdf or aluminum shell would make them real nice. Hell, sell them for $5-600 to home brewing and extractors. Or even for water temperature controllers for home growers. There’s probably demand and if you recharge old ones you’re keeping things out of the garbage dump.

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How do you get the compressor to stay on?
Is there a way you bypassed the thermostat? Or did you just keep the probe warm?

PG is your best bet because it is non-toxic and approved for food contact applications.

Ive come across a few labs that have ethylene glycol degredation byproducts on their coas.

Dont be like them.

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You realize their posts are over a year old… right?

I learned a lot by reading through year old threads- and i would hope that folks looking to DIY projects like this would stick to using as many food safe and non-toxic solutions possible- for the sake of the consumers

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