Keezer + fermentation Chamber = Fail for me. Need help

So, I have a little chest freezer, and I thought it would be great to use it to power a fermentation chamber. Well, we've had some unseasonably warm temps here and I've discovered that for me, this combination will not work.

I've got a fan pushing air from the bottom of the keezer into the ferm chamber, and a fan mixing up the air in the keezer.

The keezer is running all the time, and while the fermentation chamber is cooled to decent temps, I can tell this is not how I want things to work.

I'm thinking of getting one of the little 5500 btu window units and putting that on my fermentation chamber.

I've sized my fermentation chamber to hold a 15 gallon plastic conical, or 2 5 gallon carboys, with enough extra space to allow me to fit the AC unit.

What I want to know is, will the AC unit work?
What is the lowest temp I can expect the AC unit to provide?

Note: I live in Reno, NV, and for several months out of the year, temps will be highly variable, going up into the the hundreds.

Thanks in advance for any advice you can provide.

Do you have pictures of your setup?

How full is the keezer? If its mostly empty, adding some "thermal ballast" may help this work better.

Also, how are you taking the temperature for the keezer thermostat? If you've just modified the built-in one, that probably won't cut it for this purpose. Using an external thermostat with the probe immersed in water would be the way to go.

I was using an STC-1000 for both the keezer and the fermentation chamber.

The biggest problem was the keezer had to keep running and running, so frost built up on the wall and beer inside it froze, while the fermentation chamber struggled to keep up.

I had used a couple of computer fans to push and pull the air from the fermentation chamber. The fermentation chamber is a box about 2'x2'x3' lined with 2" thick foam insulation with an air tight door.

I've since bought a 5500 btu AC and will see how that works next. I understand that will require some modification to get to anything lower than the mid 60's, but that seems like a reasonable mod on something that cost 100$...

Thanks for chiming in!.

The fermentation chamber did do 'ok', but it was the other effects I'm worried about (frost, running all the time) especially when the temps really start to climb here in the summer months.

It sounds like you need more airflow between the chamber and keezer. Keep in mind that you need an equal-capacity path both TO and FROM the keezer...just pushing air into the chamber won't work; there has to be circulation.

Do you have room in the keezer? Move your fermenter in there. That's what I do...I ferment in a heated corny in my keezer. There is another user Huaco, that does the same?

Yep, I had equal airflow in and out. Used two 120mm computer fans. It actually worked well to cool the fermentation chamber. The problem was that the keezer was running all the time and freezing the beer.

Wide open airways in and out.

Anywah, I'll be putting my little AC unit on the back of the ferm chamber. We'll see if this experiment works.

Yep, I had equal airflow in and out. Used two 120mm computer fans. It actually worked well to cool the fermentation chamber. The problem was that the keezer was running all the time and freezing the beer.

Click to expand...

Good that you had equal airflow, but if your freezer was over-running, then you did not have ENOUGH airflow. That's the only way what you describe could happen.

You could very well be right. I might have had some unrealistic expectations as well.

Oh well, I bought a little AC unit and before my next brew, will retrofit my Ferm chamber to use that.

I think I'll like it better as I will not have to have it position right next to the keezer, or have those big silver insulated tubes connecting them.

Thanks for the input!

My setup is similar but with old freezer which I positioned vertical next to keezer.
(link to thread in my sig)

I got two pipes that connect chamber and keezer with fans in both of them to get proper re-circulation. Also, there are two STC-1000, one to control fans in chamber and other to control keezer.
It works great, with 50F in keezer I have no issues to maintain 62F in fermentation chamber.

diS, could you elaborate on your system? I'm looking to setup something like the OP of this thread (keezer w/ ferm chamber attached).

I documented (most) of my build:

https://www.homebrewtalk.com/f51/fermkeezer-357170/

If you have any questions feel free to ask.

diS said:

I documented (most) of my build:

https://www.homebrewtalk.com/f51/fermkeezer-357170/

If you have any questions feel free to ask.

Click to expand...

This is exactly what I was looking for, thanks!

Well, I got a little 5kbtu AC unit on sale for a little over 100$.

I cut a hole in my Fermentation chamber and plugged it in.

Oh yeah, After this picture was taken, I took the little copper bulb thermostat on the AC and very, very gently moved it to the bottom of the ac unit outside of the fermentation chamber.

I'm using and STC-1000 temperature controller to control the temp with a 5 minute compressor delay.

Been testing it for a few hours and it's working like a champ.

I'll be brewing tomorrow, Damn the 95 degree temperature forecast for the foreseeable future!