Swamp cooler (& warmer) questions

Jtk78 · May 17, 2017

I have been using a swamp warmer if you will. Fermenters in a large plastic tote, two aquarium heaters plugged into a temp controller, and a small fountain pump to gently move the water.

We'll now that's it's warmer out, I'll need to use the same setup for cooling. Replace aquarium heaters with ice and done. I also plan on adding a tee shirt over the fermenters for the wicking effect.

When I used it for heating, I filled the tub of water up to just under the line of the wort in the fermenter. Just below the point of them floating. Since I have the ability to do that, should I do the same when cooling? My initial thoughts are yes, but most of the swamp cooler suggestions I see say place it in a pan or small amount of water. So fill it up or few inches?

I know, build a chamber. I don't have the room for it right now. Someday, just not this one. Thanks in advance.

timdillon36 · May 17, 2017

The way a swamp cooler works is through evaporation. It is that energy that does the cooling more than the temperature of the water. Thats why it needs to be covered with a towel or shirt that wicks the water up and as it evaporates it cools.

It is the latent heat of the phase change from liquid to gas that causes the cooling. Thats why rubbing alcohol feels cold.

mongoose33 · May 17, 2017

You don't need to circulate the water to cool the fermenter. The water and beer will reach more or less an equilibrium if you fill the tub mostly with water. You can add frozen water bottles to manage the temp if you want.

Temperature swings will be slower and gradual if you have a lot of water in the tub; the bigger problem I foresee is getting the temp dialed in. You had aquarium heaters which I presume were thermostatically-controlled; you won't have any similar control mechanism if you fill the tub w/ water for cooling.

In my experience, the swamp cooler dialed the temp back by about 6 degrees. In the pic below, the ambient temp is about 64; during active fermentation the exothermic properties of the yeast will raise the temp 5-10 degrees, so in this case the swamp cooler offset the exothermic reaction. BTW, I was using the Inkbird just as a temperature indicator, you can see the temp on it.

************

Here's something you might consider: if you can buy an Inkbird (price: mid $30s), use it to regulate the temp using ice water and your pump. Fill up your tub w/ water; wrap a blanket or sleeping bag around it to isolate it from ambient temps. Fill up a cooler with ice, add the pump and enough water to start; circulate the icewater into the tub w/ fermenter to cool, let the inkbird turn the pump on and off as needed, and you'll have a fermentation chamber! Just not the same as others'. Replace ice as needed.

You'd need a way to return water to the cooler, but maybe just a long hose coiled in the water around the fermenter would be enough. Sort of like a HERMS system.

Just a thought. Good luck!

kh54s10 · May 17, 2017

The wicking and evaporation cooling comes from using the t-shirt. If you use one have the water level lower, if not fuller would be better.

If you have the temperature strips on the sides of your fermenter do not submerge them. That limited me to about 6 inches of water. It worked well, just by rotating ice bottles.

Jtk78 · May 17, 2017

Mongoose, very good thoughts. I already have a temp controller I was using to plug the heaters into. It's not an ink bird, but works well. Lowest setting on the heater thermostats was 70f and I wanted them turned off before that.

My thoughts on the full tub was to get the equilibrium you spoke of, and ice to bring it down / maintain it. I know I will have to do some monitoring and tinkering with the ice amounts.

I will really think about how I could set up the recirculation option.

kh54s10 said:
The wicking and evaporation cooling comes from using the t-shirt. If you use one have the water level lower, if not fuller would be better.

If you have the temperature strips on the sides of your fermenter do not submerge them. That limited me to about 6 inches of water. It worked well, just by rotating ice bottles.

Yeah, I made the mistake of submerging them, then added a bunch of ice to my swamp cooler to cold crash. That cashed them. Reminds me, I need a couple new ones.

NSMikeD · May 17, 2017

I love these things: ice blankets

timdillon36 · May 17, 2017

mongoose33 said:
Here's something you might consider: if you can buy an Inkbird (price: mid $30s), use it to regulate the temp using ice water and your pump. Fill up your tub w/ water; wrap a blanket or sleeping back around it to isolate it from ambient temps. Fill up a cooler with ice, add the pump and enough water to start; circulate the icewater into the tub w/ fermenter to cool, let the inkbird turn the pump on and off as needed, and you'll have a fermentation chamber! Just not the same as others'. Replace ice as needed.

You'd need a way to return water to the cooler, but maybe just a long hose coiled in the water around the fermenter would be enough. Sort of like a HERMS system.

Just a thought. Good luck!

View attachment 400793

I like this sugestion and have thought about doing this myself.

I would add 2 ports to the tub that the fermenter is placed in. One near the top and the other near the bottom. Put the pump in the cooler with ice and attach it to the port on the bottom, then attach a hose to the port at the top that will be a return to the cooler. Probably need a check valve to keep the tub from filling the cooler through the pump. With some sort of controler and temp probe to tell the pump to turn on and off.

Im not sure how constant the temp will be or what swings in temp you might see.

Jtk78 · May 17, 2017

That's a pretty good idea Tim. My DIY engineering brain is now at work.

Swamp cooler (& warmer) questions

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