You could make your own extremely efficient glycol chiller out of a mini fridge, freezer, or a wall unit. All you need is some refrigeration knowledge, an EPA Section 608 license, and know how to braze.
Purchase a cheap refrigerator or freezer.
Purchase a heat exchanger.
Then the fun part:
Evacuate the refrigerant.
Destroy the fridge/freezer cabinet. You don't need the cabinet part of the unit, because you will have refrigerant cooling the glycol or other liquid coolant directly.
Remove the evaporator coil.
Braze the cap tube from the fridge/freezer into the heater exchanger.
Braze the suction line for the fridge/freezer to the other side of the heat exchanger.
Consider adding a suction line accumulator (optional).
Connect your hoses to the heat exchanger for the liquid coolant.
Pull a vacuum to 5 microns.
Recharge the system with refrigerant.
Insulate the heat exchanger very well.
Connect your temp control, inkbird or otherwise to turn on both the compressor and water/glycol pump when cooling is called for. Alternatively you can have the inkbird or other control turn the compressor on for cooling and leave the water/glycol pump to run continuously.
You will not need the original thermostat built into the fridge/freezer, because your using a seperate control with a temp probe in the fermentation vessel. Hopefully you'll be using a thermowell.
Overall the package will take up much less space than the original fridge/freezer, because your only using the refrigeration system from the mini fridge/freezer and not the cabinet. A 4 cuft or 5 cuft fridge or freezer unit should work nicely.
- Very low footprint.
- Refrigerant directly cools the fluid. Much more efficient and fast. Much better than coiling a tube inside a fridge/freezer cabinet for water/air heat transfer or coiling a tube against an evaporator coil.
- Save money instead of buying a pre-made glycol chiller system for thousands of dollars.
That would be me. EPA Section 608 Licensed. Many years of experience in refrigeration working for a medical devices manufacturer of scientific fridges, freezers, ultra-low temp freezers (cascade systems), and cryogenic tanks.
EDIT: Just remembered. If the mini fridge/freezer has the condensing coils embedded in the side walls you won't be able to destroy the cabinet. There are units out there, typically referred to as "built in" units, that have the condensing coil and fan located at the bottom rear instead of being foamed in the side walls. One of those would be ideal. They usually have a vent under the door. Here is an example:https://www.amazon.com/Summit-Appliance-ADA302RFZ-Undercounter-Refrigerator-Freezer/dp/B08RR661ZK/ref=sr_1_3?dchild=1&keywords=built+in+undercounter+freezer+manual&qid=1612994270&s=hi&sr=1-3