Upright Freezer as a Ferm Chamber for a Brewhemoth?

Howdy Folks,

So prior to taking a bit of a break from brewing I acquired a brewhemoth conical. While it's great to be able to do variable size batches under pressure, it brought with it a larger problem of fermentation temp control.

While I have the IC for the brewhemoth, I found I was going through multiple 20lb bag of ice each batch even for just primary fermentation with no good options to cold crash, much less condition or lager.

I've been searching for a commercial beverage fridge (True for example) to fit the brewhemoth in but they're very hard to find in my area used, and when I do find them their either too small, too close to retail price or have already been sold.

In home depot today I saw this upright frost free freezer which at first measurements should fit the brewhemoth and has removable shelves (most uprights have the coils through the shelves it seems).

However, since these freezers aren't really meant to be used like a refrigerator I'm a bit worried that keeping it at a 62-68F range during fermentation, and then dropping down and holding in cold conditioning (sub 40F) may be something that the freezers compressor isn't designed for.

Can I use a upright freezer like this for what I want to do without dramatically shortening the freezers lifespan or am I better off still trying to find a actual beverage fridge?

I just set up a 20+ft^3 freezer to house my 'hemoth. I hacked into the wiring to have it do what I wanted. You could just wire/plug the cord into a controller and that will certainly work too, although the light inside won't. I've ran a few batches of ale through. An incandescent bulb provides heat if that's needed. There's also a comp. fan that is on constantly. This helps with stratification immensely.

StMarcos said:

I just set up a 20+ft^3 freezer to house my 'hemoth. I hacked into the wiring to have it do what I wanted. You could just wire/plug the cord into a controller and that will certainly work too, although the light inside won't. I've ran a few batches of ale through. An incandescent bulb provides heat if that's needed. There's also a comp. fan that is on constantly. This helps with stratification immensely.

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Happen to have the brand/model of the one you used for your hemoth(s)? I assume the wiring hack was because you weren't using a controller?

I'll check when I get a chance. I did use a controller. It's a ranco-type that I stole from an old aquarium project. I hacked the wiring so the other powered parts of the freezer would still be operational even when the controller is not activating the cold side relay.

I drilled through the roof (carefully! there are coils in there!) to pass in wires for the incandescent heater bulb, the ranco probe, and the fan. The fan is switched so I can have it off when I'm filling the fermenter with wort, as I don't want air blowing around but I do want the built in LED on so I can see in the top of the 'hemoth.

The compressor delay is not operational so I have to be careful that there is a lot of mass around the temp. probe. I tape it to the side of the 'hemoth under a good gob of bubble wrap.

I don't have a brewhemoth but I do use a conical that has stainless coil in it for cooling. Instead of using ice I tore open an air conditioner and submerged the evaporator coil into a propylene glycol/water bath. I use an STC 1000 controller to turn the air conditioner on and off and control the temp of the bath, which is kept at 25 degrees Fahrenheit. Another controller controls a submersible pump that pumps the fluid through the coil to control fermentation temp.

The air conditioner more of less takes the place of the ice you were previously using. Requires some DIY but it is another option. I probably spent $100 with everything by sourcing most of it on craigslist.

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I have what looks like an older version of the same freezer for my upright keezer. I've had no problems keeping refrigerator temps (I used the coarse adjustment of it's own thermostat). If you decide you need to drill it for anything, the back seems to be the safest place to do it. I have a co2 line running out the back of mine.

I have a True version that I use. Don't know the model number off hand but can grab it next time I'm in. I don't know what dimensions you need to fit but my conical fits fine just have to cut legs so it's not so tall and still be able to drop yeast.

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I went the DIY glycol route with a hacked up AC unit. Pretty simple to do and the space savings is amazing. I keep the unit under a table next to my brewhemoth. I have the dual coil option which is (2) 20' x 3/8" coils. I only use one coil to keep it cool. I keep my glycol at 25ºF. My garage gets up to 105ºF in the heat of summer. I can ferment at 68ºF all day long with no problems. I can cold crash down to about 40ºF with the ambient at 105ºF and no insulation on the conical. With a little insulation I imagine I could go lower. In the other months I cold crash around 35ºF.

I still haven't decided which route to go. For those of you who went the DIY ac/glycol route. Do you have to run two controllers? One to manage the AC unit and coolant temp and one to monitor the fermentation temp and turn the pump on or off?

The benefit to the upright chest freezer seems to be in space saving and having a completely self contained unit. Whereas the benefit of the DIY route is primarily in cost savings as it's roughly 1/4 the cost of a new upright freezer.

I find my diy glycol system to be a huge space saver! I made a small controller for the ac unit from a mh1210 unit off ebay and then I use a gen 1 blackbox to control the temp of the brewhemoth. The glycol unit sits under the work bench and out of the way. The only floor space I use of the amount it takes for the fermenter. I use a harbor freight submersible pump in the glycol bath to pump to the fermenter. It seems to work fine in a 70/30 water:glycol bath at 25ºF.

For those of you who went the DIY glycol route. Is it possible to use the glycol system to supply the cold side of a plate chiller instead of using a garden hose? Can the glycol system keep the coolant temps down enough with the return coming in hot from the plate chiller and does the propylene glycol have any ill effects on the chiller itself?

Jukas said:

For those of you who went the DIY glycol route. Is it possible to use the glycol system to supply the cold side of a plate chiller instead of using a garden hose? Can the glycol system keep the coolant temps down enough with the return coming in hot from the plate chiller and does the propylene glycol have any ill effects on the chiller itself?

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Short answer, No.

Jukas said:

For those of you who went the DIY glycol route. Is it possible to use the glycol system to supply the cold side of a plate chiller instead of using a garden hose? Can the glycol system keep the coolant temps down enough with the return coming in hot from the plate chiller and does the propylene glycol have any ill effects on the chiller itself?

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I was going to do this with a 2 stage system so the garden hose would knock down to 110 and then glycol for the rest of the way. But then I realized that my glycol system could knock 15 gallons of wort from 85-90 down to 68 in about 20-25 minutes so I do that now.

I keep a 10 gallon glycol bath at 25F and it can recover a coutlet degrees per minute with a 6kbtu actually unit.

I don't see any chemical problem,s with glycol on the chiller. Bigger glycol systems use a plate hex between the refrigerant and the glycol instead of an immersion system.

sandyeggoxj said:

I was going to do this with a 2 stage system so the garden hose would knock down to 110 and then glycol for the rest of the way. But then I realized that my glycol system could knock 15 gallons of wort from 85-90 down to 68 in about 20-25 minutes so I do that now.

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Looking at the equipment I have on hand, my spare cooler is a 30qt, allowing for up to 20% loss to headspace and displacement we're looking at a 6 gal glycol bath.

Even though I only do 5.5-12 gal batches I suspect that wouldn't be enough volume to keep up with the heat exchange from a plate chiller going from 212f to sub 90f during transfer.