Chest Freezer 101

Any chest freezer experts out there? I’m using one as a fermentation chamber and have an Auber TD 100 temp. controller. I have just been testing this tonight and find that I’m chasing the temp quite a bit although my actual temp isn’t moving much.

I’m using a small piece of bubble wrap with the sensor pressed against the plastic Speidel fermenter with some tape.

My settings are 65 cold set point and hot set point is 61. The differential is set to 2 degrees and the anti short point is set to 5 minutes.

The actual water temp has been floating around 67.5-68, again, I have only run this test for a couple of hours and I’m not sure how long to expect a normalization of temps.

The problem during testing this was that the controller would kick on at 65 and drop the temp to ~60 or so and start to climb back up. It would get up to 67 and kick back on. This repeated a couple times each hour and never seemed to equalize and run less.
Maybe this is normal?

Check it in the am after it has set undisturbed.

Yeah, I should probably plug her back in.

So, you’re measuring air temp in the freezer as well as the probe taped to your fermenter?  You care about the temperature of the beer, so I’d only pay attention to that. The temperature controller should keep the freezer on until the beer temp drops below your set point.  Why is the freezer turning off if the water temp doesn’t fall below 67?

No, I’ve taped the sensor to the side of the fermenter.  I suppose it’s actually measuring air temp though as fast as it’s changing.

Attach probe so its against where the beer is, not head space. Insulate the probe so its only reading the fermenter wall not the air inside the freezer. I set my hot and cold side to the same temp with one degree differencial. So if mine is set at 50, the freezer comes on at 51 and the heater comes on at 49. At first it will work hard but once all that beer mass is at 50 it barely kicks on at all. Maybe once every hour or two. Within a couple hours of putting my beer in the chest its at the set temp and always stays right there. The display on your controller becomes your new thermometer. Measuring the air or a glass of water is a sheer act of futility. The air im my chest is usually the same as the beer temp or close, but when tge freezer kicks on the air will be freezing and when the heater kicks on the air will be hot. I already know that, because I have a freezer and a heater… I only care about the beer temp.

I took a piece of styrofoam and hollowed out a section for the probe and use a bungee cord to strap it to the fermenter.  Set the differential to 1 degree.

When I crash cool though, I take the probe out of the styrofoam and let it go with ambient.  Then it’s not running full out until the beer cools to 32F.  It gradually comes to ambient over time and does not overwork the condenser.

Dave

Seems like a good plan. I look at it as a chance to let er rip, run hard and blow out the carberators, so to speak.

So I think I have this thing dialed in…cycling about once an hour (~90+ degrees in the garage right now) and holding my make believe beer at 65 degrees.

Does anyone know how often their chest freezer is cycling in warmer climates?

My garage has been sitting around 88* the past couple days and has been cycling Id guess every 30-40 min. So seems pretty good to me.

I dont really monitor mine, but when I go out to the shop (usually once a day) I’d say 9 times out of 10 its not running. When im out there all day brewing, it comes on 3 or 4 times in warm weather, never in the winter.

Sounds about right. Maybe every 30 minutes for five depending on ambient temp and how many fermenters are  going.

I’ve been running the ac all week btw…

That first morning with a chest freezer and you open the door up and see your beer chugging away and the temp is right where it should be  ;D

What size freezer and fermenter is that? I’ve been lusting after one of those fermenters.

That is a 20L (~5.28 gallons) Speidel in a shiny new GE 7 cu.ft. freezer (linked below). It fits my 30L (~8 gallons) fine as well. I can’t say enough about the fermenters, perfect in every way!

http://www.homedepot.com/p/GE-7-0-cu-ft-Chest-Freezer-in-White-FCM7SHWW/205462818

I LOVE that!

It’s a great feeling

Thanks I was interested in how the spiedel fit.