Glycol chiller question

[phillip_h]

I recently put together a DIY glycol chiller with a 5000 BTU window unit and an ice chest. It's currently doing a great job of keeping the fermenter at 60°F in a garage that it about 80-85°F.

I have it hooked up to a Johnson digital temp controller and I'm keeping my glycol reservoir at about 36°F. The controller shuts the AC off when it gets down to 36° and then it turns back on when it gets up to like 44°. I set the short-cycle delay to 8 minutes so that it doesn't wreck the compressor

It seems like the window unit is running pretty much any time I check it. Is this pretty typical? Or should I make some adjustments in my settings?

 

[dthompson79]

What is your glycol to water ratio and what is the total volume? how big of a fermentor are you cooling

 

[phillip_h]

Right now it's 1 part glycol to 2 parts water, but I'm realizing that it's too much glycol. I have a 7 gallon ss brewtech conical with the internal chilling coils.

 

[dthompson79]

thats sounds right that is a 33% glycol solution freeze protection to about 5 degrees. Most breweries use a 35% with a glycol set point of about 28 degrees. It should be easily maintaining temp unless something is wrong with the window unit. I have heard of systems like yours cold crashing multiple several barrel fermenters at once. Make sure the coil is as submerged as possible and if you can have something recirculating the mix while the compressor is running that is even better.

 

[oakbarn]

How much glycol mix do you have? More is better. If you are cooling a small amount then then using it to cool a fermentation, you may not have enough volume. I have no issues chilling a 30 gal fermemntor using a 75 qt igloo cooler full of 50/50 glycol. I set my swing at 4 degrees F using a BCS 462. I run a pump also under a 1 degree swing to pump the glycol. You need to make sure the ambient temp of the AC is 60 plus or it will not cool.