Keezer/Kegerator temperature stratification

My freezer conversion is working pretty well for the most part, but I'm getting a fair amount of foam. I keep the freezer at 38F controlled by analog temperature controller. The controller's temperature probe is in a bottle full of water on the bottom of the freezer. I also keep a bottle of water near the top of the freezer with a thermometer in it. That thermometer reads around 55F. Since the faucets are mounted high in the freezer box, I thinking maybe that temperature variance causes foaming (I run my regulators at 10psi, through 6ft of bev line - and I've experimented with psi, but this set up has run successfully in full sized refrigerators).

Has anyone employed a muffin fan in their freezer to circulate cold are and stop stratification? Wondering if I'm missing something. The foam is tolerable, but it should be better.

I was just looking at 120vac fans today to fix this. The basic concept is to put a fan inside that does nothing but move air around.

I'd be curious what CFM is sufficient. I found some Sunon fans in the 11W range, but so far nothing lower power.

I mounted a 110v AC muffin fan to the lid of my freezer for just this reason. It made all the difference. I have the controller probe mounted through the collar just below the fan. There's no need to put the probe in a water bottle. That does nothing but decrease the response time and it will cause the controller to overshoot and undershoot the desired temperature. Trust me on this. I've tried it both ways and then some and it's not the way to go.

Nice Cat22, did you wire this fan into the freezer's panel so that it only runs when the compressor runs? Or does it run full time?

ebeer said:

Nice Cat22, did you wire this fan into the freezer's panel so that it only runs when the compressor runs? Or does it run full time?

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No. I found that it works much better to have the fan running full time. The fan only uses 22 watts of power, so it only costs about 5 cents/day to run. Not only does it keep the kegs and lines at a uniform temperature, but it also keeps the shanks and taps cold. This was a cheap and easy mod that really works well. Wish I'd done it a lot sooner.

So what did you do, just splice a power cable into it? do you need to worry about the AC/DC conversion?

Bean said:

So what did you do, just splice a power cable into it? do you need to worry about the AC/DC conversion?

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There's no AC/DC conversion. It's a 110v AC fan and can be plugged directly into a wall outlet. I simply ran some common 18/2 lamp cord to it through the collar. I have a power strip mounted on the wall behind the freezer which handles the fan and the freezer among other things. The power cord is visible in the pics and so is the controller probe.

Catt22 said:

There's no AC/DC conversion. It's a 110v AC fan and can be plugged directly into a wall outlet. I simply ran some common 18/2 lamp cord to it through the collar. I have a power strip mounted on the wall behind the freezer which handles the fan and the freezer among other things. The power cord is visible in the pics and so is the controller probe.

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My fault, I thought you used a basic computer fan. Where did you pickup the AC fan?

If you can't find an AC fan - (radioShack does sell some) any DC fan will work - wire it up to a wall-wart (cell phone charger). I'm running two fans, very similar to Catt's set up. CFM probably doesn't matter much in the enclosed space, as long as it's moving the air around

Bean said:

My fault, I thought you used a basic computer fan. Where did you pickup the AC fan?

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I have a friend that gets them wholesale for me. The ones Radio Shack sells are overpriced, so I would suggest looking elsewhere. You can easily google up some online sources or go to your local computer supplier place such as Micro Center if you have one. Some audio stores stock them too as they are frequently used to cool amplifier cabinets and such. As mentioned above, a 12v DC fan will work just as well. I prefer the fans with ball bearing motors, figuring they will last longer and probably produce more oomph per watt. I've had mine running for almost two years without a problem. One nice thing I've noticed is that there seems to be less condensation forming in the freezer. I'm not sure why this is, but that's what I've observed.

Awesome! Well I am going to install one in mine this weekend. Will see how it goes. Thanks for getting back to the post so quickly

I love this forum. It keeps giving me great ideas for my project. I hate to hijack the post but I just two quick questions.

1. When the lid is closed to you have the air being drawn from the bottom of the freezer to the top (which is what I am guessing), or air being pushed from the top down.

2. My chest freezer that has a light. When I put my collar on the lid can I just use the wiring from the light to power the fan. With the colla,r the switch will always be on the on position.

I wired a three DC fans with a cannabalized wall wart. One I point upwards, two I point downwards. I am still getting some temperature stratification so I need to play around with the positioning a bit I think. It also may be possible that my kegs are too tightly packed in the freezer, and preventing the air from really moving around...

DirtyPolock said:

I love this forum. It keeps giving me great ideas for my project. I hate to hijack the post but I just two quick questions.

1. When the lid is closed to you have the air being drawn from the bottom of the freezer to the top (which is what I am guessing), or air being pushed from the top down.

2. My chest freezer that has a light. When I put my collar on the lid can I just use the wiring from the light to power the fan. With the colla,r the switch will always be on the on position.

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A1 The fan blows from the top downward in mine, but I wouldn't think it would make any difference which way it is directed. The important thing is to just keep the air circulating. IOW, it doesn't matter.

A2 Sure, you could use the wiring from the light to power an AC fan so long as the power stays on with the lid closed. With a collar it would also easy to simply drill a hole for a power cord whether it be AC or DC.