Mini Fridge Temp Control

[Beernik]

My office is in the midst of moving to another building. It really sucks. I'm losing 40% of my cube space, 1.5' off the top of my cube wall, and my window.

But the one good thing: no mini fridges are allowed in the new building. So today I just scored a cheap used mini fridge large enough for a carboy.

I'll have to make some modifications to it. In particular, readjusting the freezer shelf. It looks like I can remove 4 for screws and pull it out or let it hang in the back.

What's the best way to temp control one of these? The main purpose would be conditioning ales and lagering. But I might need to do some fermentation control during the hottest part of the summer when my cellar is too warm.

 

[Walker]

Check this thread:
https://www.homebrewtalk.com/f51/anyone-use-temp-controller-off-ebay-173021/
and here is a build thread using that kind of item:
https://www.homebrewtalk.com/f51/ebay-aquarium-temp-controller-build-163849/

The controller reads in *C instead of *F, but....

Other than that, you can always buy the ranco or johnson controller that many online and local homebrew shops sell, but I think the ebay thingy would be the cheapest solution if you don't mind a little DIY work.

 

[Beernik]

Thanks.

I was hoping I could get off a little easier because it's a smaller fridge.

I found a plugin thermostat for small AC units and space heaters and though about using it. But then I realized it has a built in temperature probe. Which means I'd have to run a power cord both in and out of the fridge. And I'd either have to buy 2 if I want heat and cold available at the same time or physically flip a switch to go from one to the other.

If I got 2 of them, I'm into it $70. It looks like I can pick up the aquarium controller for $30 including shipping. I doubt all the misc parts for the controller will cost me $40, so I might as well order one or try to find a local retailer.

 

[Beernik]

Geez, you would think aquarium supply stores in Utah had never heard of the Internet. Looks like I'm ordering from ebay.

 

[RichN]

Beernik,
What is the brand and model of te fridge you got?

 

[Beernik]

I'll tell you Monday, I haven't brought it home yet. And I'll be able to tell you the model number too.

But I can tell you it's interior dimensions not including the bottom shelf and with the freezer shelf removed: 18" wide x 13" deep x 22.5" tall.

 

[Beernik]

It's a GE, model GMR04. It has 4.3cubic feet capacity.

 

[Beernik]

RichN,

if you are thinking abou getting on of these, you might want to hold off a couple days. I just discovered dealing with the freezer is more difficult than I thought. It's a hard freon pipe that comes out the back of the fridge and connects to the freezer plate. Allegedly the pipe is bendable, but if it cracks, it will leak freon.

I'll see what I can do with it this week. I might have to leave the freezer in, pull out the bottom shelf, and build a collar.

 

[Swordsman]

I have a similar fridge by magic chef, with that pipe on the back of the freezer plate. I was just going to cut off everything back to a few inches from the pipe with a dremel or something. Not sure how that will affect my colling ability, but since I got it for $40 I'm not too worried, and it doesn't really need to get that cold anyways.

 

[Beernik]

I thought something like that might be another option. I was thinking I might just cut a slot for the carboy neck. But then there might be enough of a temp differential to shatter it.

I won't know until I look at it closely tonight.

 

[Beernik]

Awesome!

I took it apart. The pipe in the back didn't cause any problems. I had to remove the thermostat and force the freezer plate around the shelf supports, but it was extremely easy.

The fridge is big enough to hold a 6 gallon carboy without an airlock or a 5 gallon bucket with an airlock.

The plastic shelf is a little worrisome. It's too flimsy to support 5 gallons of wort. I put two of the racks right above it. That seems like it might be strong enough. If not, I might have to make a plywood box to replace it.

I'm thinking of putting foam over the metal plate to make sure it dosen't physically contact the fermentors. I want to make sure I don't end up with a shattered carboy or cold spot in a bucket.

Right now I'm testing it out, I've got it on the minimum setting to see what temp and range it will hold tomorrow. Then I'll do the same with the maximum setting the day after.

My wifi is down and I can't upload from my phone. I'll get pictures up as soon as possible.

 

[Beernik]

It reaches a set temperature faster than I thought. On minimum, it keeps 42.5F +/- 2.5F. This morning I cranked it to maximum. It was looking like it will keep 18F +/- 1.5F.

Tonight, I'll put the fridge in the garage, put a full 5 gallon bucket in it, and see how well it holds the temp.

Now let's see if I can get these photos loaded.

 

[Bassman]

Why can't you remove the bottom shelf and clear compartment? If you rested the carboy on the bottom would that work or is it at an angle?

 

[Walker]

There might not be enough room between the compressor hump and the door to do that.

 

[Bassman]

There might not be enough room between the compressor hump and the door to do that.

Thanks.

 

[Beernik]

If you are adventurous, I've heard of people pulling the compressor out (but still connected), then cutting out the hump and making the floor flat.

 

[azscoob]

if you pulled the inside door panel off you would have a flat door and might make room for the carboy on the floor, thats how it worked out for me, I cut the panel to leave the attached seal in place and that was all I needed in addition to moving the freezer as you did. I have since added a 2x12 collar to increase capacity to 15 gallons
here is mine before finishing