Glycol chiller with dehumidifier?

I have seen homemade glycol chilling systems in other threads here that used a cooler for a reservior and an A/C unit as the source of cooling. The A/C was partially dismantled and the condenser coils were placed into the glycol/ water mixture in the cooler. Could this be done with a dehumidifier? I believe they also have condenser coils but unsure of how this could be done. Any help/ knowledge would be appreciated. Thanks.

I would imagine it could work. the operation is the same, I think that dehumidifiers are just alot less BTU, as they are not meant to cool a room and they dont vent the heat from the condensor coils to the outside.

just and FYI

condenser = hot
evaporator = cold

definitely ...I have a thread in here somewhere ....

The evaporator is down in the old water collection tank (which now holds glycol solution) along with a submersible pump to circulate the glycol through the coil in the fermenter.

I have an ongoing DIY thread which includes my antique dehumidifier conversion to a glycol chiller.

The biggest problem I have is getting the lift I need. The small pumps I started with were not strong enough to lift the glycol even close to the lift specs. So a search online resulted in a much stronger pump, for the same price I paid, about $20. Now I need 2 more.

I find that if I keep both ends of the tubes submerged in the glycol, the syphon action on the return side helps with the lift issue on the supply side

SleepyCreekBrews said:

I find that if I keep both ends of the tubes submerged in the glycol, the syphon action on the return side helps with the lift issue on the supply side

Click to expand...

I manually primed the tubing, and it still could not lift the glycol 3 feet and push it through the radiator in the upper chamber. They are the smallest pond pumps you can buy. I ended up getting 2 400 gph for $25 each on Amazon, and moved the other 2 (291 gph) to the upper chambers. Net loss of almost 1 gallon of glycol with these 4 vs the 2 small ones I started with!
The cool down time on my lower chambers (with 'lagering jackets') dropped noticeably with the 400 vs 291 pumps. The upper chambers are just for fermentation cooling, so I don't need the higher capacity in them.

got a question, since you operate this with a dehumidifier. (and I plan on it too)

1) Does the glycol evaporate?
2) how often do you have to add more water?

I assume the container is not very well sealed in there?

Minbari said:

got a question, since you operate this with a dehumidifier. (and I plan on it too)

1) Does the glycol evaporate?
2) how often do you have to add more water?

I assume the container is not very well sealed in there?

Click to expand...

I've been running mine about 2 months now, and I think the tank level actually went up due to condensate ice buildup on the exposed tubes of the evaporator. Twice during 'updates' I had to lightly tap at it to break it off the coils, and the level the last time was right at the opening where the tubes come in. Due to the limited tubing length, and how I had to finagle it into position, the level is limited by the tubes.

I recently learned in another thread that there are 2 formulations for the non-toxic type, Pure glycol, and glycerine/alcohol/water. Based on what I learned after that the -100 is glycol and the -50 is the blend. I would expect the blend to evaporate, but maybe it's minimal at 28F, if that's what mine is.

The tank is not sealed at the top, just a snug fitting lid, with foam over it, and now I added a sheet metal cover over the top, down the back & sides. Trying to deflect the incoming air as best I can. Again the tubing limitations, and desire to maintain the original case means the tank top is 3 inches above the condenser bottom, so the air flow has to go in over the tank and some goes down. I think the back 3" of tank was making the perfect condensation point. As soon as the humidity goes up a little a puddle of water forms under it. I put a tray under it a few days ago, and not a drop, but the humidity has been gone since then.

I may tear it down over the winter and wrap the entire tank with something to keep the air from being able to get in anywhere. Only bummer is I can't have more than 1/2" of insulation on the sides and bottom and have it fit in the case still. A custom case is always an option, but being able to re-use this one made the project vastly easier. And if I go that far, I might as well make a new tank that better fits the bigger pumps, and has more volume. I have at least 2-3 inches I could use before it sticks out the back.

I use a 45 pint/day dehumidifier in my glycol chiller - it works out to around 4000 btu/hr chilling capacity.

Mine is torn apart and the evaporator seperated from the condensor, with the evaporator (the cold part) in glycol

One thing to watch out for is if the dehumidifier is rated for low temp operation, there will be a bypass solenoid for the freon that will make it very difficult to relocate the evaporator.

My short tubing and routing made it very difficult to move the evaporator. I had to turn it 90° and bend the tubes to get it down to the tank position. I had to disconnect the compressor and condenser, then lift it all up to lower the evaporator into the tank. Quite a maneuver. Mine is 70`s vintage I suspect and nothing fancy.

I also have not had a problem with evaporation ...on the contrary, if I don't cover that open slot between the tank and the fan, I get a tremendous amount of frost build-up that leads to the tank overflowing when it thaws. I cover it with some masking tape and no problem

Minbari said:

got a question, since you operate this with a dehumidifier. (and I plan on it too)

1) Does the glycol evaporate?
2) how often do you have to add more water?

I assume the container is not very well sealed in there?

Click to expand...

^^^ good to know, thanks

SleepyCreekBrews said:

definitely ...I have a thread in here somewhere ....

The evaporator is down in the old water collection tank (which now holds glycol solution) along with a submersible pump to circulate the glycol through the coil in the fermenter.

Click to expand...

Thanks man! I just watched your youtube video and went straight to Craigslist. I'm now staring at that exact dehumidifier in excellent used condition for $45. Good price? Thinking you said you only paid $25 for yours.