Need advice regarding running temperature controller into freezer

I'm close to being ready to brew. I got the freezer off CL a few weeks ago, the Johnson A419 controller came in the mail today, and in a few days I'll get the equipment kit and other goodies SWMBO got me for my birthday that have been sitting upstairs for a couple weeks (painful to just have those sitting there in a box....I feel like a kid waiting for Christmas). The freezer will serve as a dedicated fermentation chamber. Now I'm just trying to figure out what the best way to run the temp controller into the freezer is (I imagine I'll let the temperature probe stay suspended in a jar of water once in the freezer). I've considered running the wire with the probe through the drain at the bottom of the freezer, but I'm not sure if I'm asking for trouble. I could drill a hole (in the side?) if I'm careful. The door closes around it when I just just run it into the freezer, though I wonder if that will be annoying dealing with it each time and whether I'm getting a good seal (I guess to get a good idea I could put a lantern inside and see if any light shines through when the temp probe wire closed in the door). For those of you who have tackled a similar issue, what have you done? Thanks for your help.

I could drill a hole (in the side?) if I'm careful

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Be very careful when drilling a hole in the side. I got a free freezer where the racks were the cooling element. I drilled a hole in the side not realizing that there was a coil running up through the side. Needless to say, I won't be able to use that freezer anymore.Thank god it was free.

That option certainly makes me the most nervous. I really don't know anything about freezers except they're cold. This is a frost-free so the racks don't do the cooling. I still don't know what's in the side though, and how good of an option drilling tnto the freezer is.

I just run the probe wire through the door opening and let seal pinch it.since we are dealing with maintaining 60-70 degrees,I don't sweat the small air leak it creates.

I know it can be done. Here is a link to a thread on the issue.

https://www.homebrewtalk.com/f51/freezer-conversion-coils-shelves-136689/

This thread deals with the kind of freezer I have. For your model you could probably find a manual online that has a schematic of exactly what is in the sides and find a safe place to drill. I probably should've done that first for mine. lol. But I was so excited to finally have a use for this freezer that had been sitting in my garage for a year.

On a side note, using a jar of water in the fridge won't give you the actual beer temp. It's a smaller mass of water, and since there is no fermentation, it won't account for the heat created by the yeast during fermentation. You may want to consider taping the probe to the carboy/bucket and then taping some bubble wrap around it.

hey, you may want to check out this thread
https://www.homebrewtalk.com/f51/gu...mostat-32f-eliminate-external-control-249612/
I'm not sure if it will help ya or not, but I ran into it earlier today and may save ya a bit of headache.

I also run the probe through the door opening...no problems with the seal
I also tape the probe to the fermenter, with bubble tape on top of it....works well.

akryder said:

On a side note, using a jar of water in the fridge won't give you the actual beer temp. It's a smaller mass of water, and since there is no fermentation, it won't account for the heat created by the yeast during fermentation. You may want to consider taping the probe to the carboy/bucket and then taping some bubble wrap around it.

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+1 I measured ambient temperatures for the first 2 months I had a fermentation chamber. I did not get true control of fermentation temps until I taped the probe to the carboy and insulated. Now, I can set my controller to 66* and I know that my beer is staying at 66*.

akryder said:

On a side note, using a jar of water in the fridge won't give you the actual beer temp. It's a smaller mass of water, and since there is no fermentation, it won't account for the heat created by the yeast during fermentation. You may want to consider taping the probe to the carboy/bucket and then taping some bubble wrap around it.

Click to expand...

Thanks for your thoughts on this. I know the mass is smaller but I thought the probe in water would still be more representative of the actual temperature in the fermentation vessel than having the probe on the outside, but it sounds like that is wrong. Let me ask you, does taping the probe and insulating work for plastic buckets, or would only the glass carboys give a good reading?

Fish826 said:

For your model you could probably find a manual online that has a schematic of exactly what is in the sides and find a safe place to drill. I probably should've done that first for mine. lol. But I was so excited to finally have a use for this freezer that had been sitting in my garage for a year.

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Yeah, unfortunately I can't figure out what model this is, just the brand. I've looked for an identifying number all over the fridge but can't find it.

fat_bastard said:

i just run the probe wire through the door opening and let seal pinch it.since we are dealing with maintaining 60-70 degrees,i don't sweat the small air leak it creates.

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+1

walrusbt said:

Thanks for your thoughts on this. I know the mass is smaller but I thought the probe in water would still be more representative of the actual temperature in the fermentation vessel than having the probe on the outside, but it sounds like that is wrong. Let me ask you, taping the probe and insulating work for plastic buckets, or would only the glass carboys give a good reading?

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Works for buckets just fine.

Fat_Bastard said:

I just run the probe wire through the door opening and let seal pinch it.since we are dealing with maintaining 60-70 degrees,I don't sweat the small air leak it creates.

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I thought about doing this too, but I was more worried that opening and closing the door on the probe leader would cause it break over time. Kind of like bending a soda can tab back and forth until it breaks off. The leader on my probe seems real fragile.

I found the model number and while searching for the manual online a HBT thread showed up with how one person here set up the same freezer...https://www.homebrewtalk.com/f51/dutch-s-cadillac-fermentation-chamber-build-251579/

Fat_Bastard said:

I just run the probe wire through the door opening and let seal pinch it.since we are dealing with maintaining 60-70 degrees,I don't sweat the small air leak it creates.

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I use a chest freezer and I do the same thing... no use putting a hole there...can't remove it if you don't need the probe anymore.....

I lose no temp because of the very small gap created by the wire against the gasket. It can also be moved or re-arranged if you do it my way.

Good Luck.

I personally bought a chest freezer with a Ranco controller, and used some tape over the wire running under the seal (no drilling) to minimize the bump (and maximize the seal) and it works fine.

I brew ales, so 60-70 seems reasonable for this approach. If I was into lagers (in the 30-40 range), the air seeping into the freezer may be important to minimize condensation, but that isn't something that I have experienced so far. I do take the odd rag and wipe the walls to get the moisture, but once it hits temperature it seems to work great.

EROK said:

I use a chest freezer and I do the same thing... no use putting a hole there...can't remove it if you don't need the probe anymore.....

I lose no temp because of the very small gap created by the wire against the gasket. It can also be moved or re-arranged if you do it my way.

Good Luck.

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since cold air is heaver than warm air, every time you open the door all the cold air flows out replaced by warm air. A chest freezer would be more cost effective but probably not able to hold as much and would take up more floor space.

C-Rider said:

since cold air is heaver than warm air, every time you open the door all the cold air flows out replaced by warm air. A chest freezer would be more cost effective but probably not able to hold as much and would take up more floor space.

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Freezer is already pucrhased, and was vetted against chest freezer, Basically it came down to (1) footprint...chest freezer was going to have to be small, the upright fits perfectly (2) I think the dumping cold air thing is probably a bit overplayed...how often is everyone opening their fridge and how quickly does everyone think a 5 gallon themal mass will warm up...I'm guessing slowly.

walrusbt said:

Let me ask you, does taping the probe and insulating work for plastic buckets, or would only the glass carboys give a good reading?

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I've used on buckets, bottles, and carboys and never had a problem. All should stabilize eventually, and read the beer temp.

walrusbt, as you know, I have the exact same freezer. I drilled a hole in the side of my door for the probe wire.

If you want to drill through the side, you could check by removing the plastic insert that holds the shelf. Feel around for lines with a hanger, etc. then drill AT THAT SPOT if clear. CAREFUL.

On my freezer, I can't find any condenser coils. I know the evaporator coils are in the back wall of the freezer. I have a feeling the condenser coils may be in the side walls.

Here's some pics ...

I have a similar 20 CF freezer that I am in the process with. I like the idea off drilling in the edge of the door. I took my shelving door/plate off and I am thinking I might cut out the perimeter where the screws were to rehang will the seal....maybe going in behind the seal and adding some foam sealant.

I would just pinch it in the seal on the hinged side of the door...easy and out-of-the way. Tape it to the inside.