Keezer build questions

[Will333]

I'd like to build a keezer and have a few questions:

For the temperature control - is there any difference between the stc 1000 and the inkbird thermostats? Is one better?

Then I'd have a heater in the freezer, something like a 45W tube heater?

And then the heater and freezer would both plug into the thermostat and either one would be switched on to keep the required temperature?

Lastly, would I need a fan to circulate heat and will the heater be bad for the beer in the keg that it is closest to (I only have a small chest freezer)?



Lots of questions, sorry! But once I have sorted these things out then I can get on with building...

[BrannigansLove]

The Inkbird 308 doesn't require you to wire anything up, you just plug your cooling (freezer), and heating (tube heater) into the provided sockets, and stick the probe in the freezer.

[gobuchul]

I use heating cable in mine, cheaper than the greenhouse heater and spreads the heat the full length of the space.

Depending on the location and the time of year you don't need a lot of heat. Mine sits in the garage and I disconnect the heater from about April to November. Once your beer is chilled down it is pretty thermally stable and so is the inside of the freezer.

A fan certainly helps keeping the air circulating and air temperatures steady.

[Fil]

An stc1000 is a way more flexible controller If you can get a V1.0 box And can spend the time to reflash it with a brewfridge specific upgrade.

https://github.com/matsstaff/stc1000p allowing such featurs as rampable temp changes, periods @ different temps programmed in advance and even remote monitoring of temp and status with a £1 433mhz RF chip addition

[Kev888]

A fridge/freezer for controlling keg temperature isn't quite as critical as controlling a fermenter, and generally you only want a modest temperature (say around 12c for ales). The choice of controller largely depends on if you want a pre-wired (just plug-in) system or whether you want to save a little money and are competent to wire an stc (or similar) yourself.

45watts or so of heating should be ample for most freezers/fridges, maybe up to to 60w if it were in a freezing garage in winter; over-egging it can be dangerous so steer clear of typical room/fan type heaters which are usually in kw territory.

Any thermostat that can control heating AND cooling automatically would be suitable. Some seem similar but can only control heating OR cooling depending on manual configuration; these are only suitable if your environment only needs one or the other. Unfortunately some sales pages are a bit unclear, saying heating and cooling but not meaning it can automatically choose, and there are sometimes different versions of the same controllers, so go with one that is clear.

Fans can even out the temperature, though thats more worthwhile in (say) a tall larder fridge than a small chest freezer, and also more worthwhile in a fermenting cabinet then in keg store. If you choose to use a fan, go for a fairly small one, preferably low voltage where liquids may be splashed about - a PC case fan is a pretty good choice IMO and gets the air moving well enough in small spaces. Avoid large mains fans, their power tries to heat up the fridge/freezer much more.

Its possible that a keg close to the fan may be a tiny bit cooler if the fan is blowing air from a cold surface onto it before others. Again not critical for a keg store, but try to direct the air to make a swirl around the fridge/freezer rather than to play on a specific keg.

[Will333]

Thanks for all the help! How insulated should the collar be? It will be in the house - ranging from 10 to 20 degrees C.

[gobuchul]

I have insulated the collar on mine with 20mm polystyrene. It's definitely made a difference, the MDF used to feel cold to the touch on the outside before I lined it.

Anything would help, depending on much effort you want to put into it. Even bubble wrap would help.

[Jonnyconga]

I'd add, if it's in the house you won't need a heater in there at all. Mine is in the shed and I don't heat it.
I would guess that a chest freezer would be coolest at the bottom and this is where the beer is drawn from if using corny kegs. I put the probe at the bottom of the freezer and don't bother with a fan.
You can always add stuff if you want to later.

[Kev888]

Yes, if the ambient temperature (reliably) doesn't dip below your chosen beer temperature then no need for a heater. I needed one in my shed during winter, but that depends on where you live and what temperature you keep your beer at.

The beer with its large thermal mass in an insulated freezer will ride small/short dips in ambient temperature, but you don't want the beer itself to noticeably change temperature. That will make keeping consistent carbonation levels much harder, and therin lies one route to foaming when drawing a pint.