Chest Freezer Info

[egolds77]

I've just recently converted a chest freezer and installed a computer fan to circulate the air. I was wondering where people are generally placing the temp probe from their digi controllers and where have they mounted their fans and whether it is blowing or sucking the air.

I've noticed a big variation with placing it in different places and heights which effects how quick the freezer warms up and starts again which can be quiet often which I don't like as it's going to cost me money.

 

[jlm]

Between a couple of kegs, preferably fullish. Keeps it from cycling on and off too often, and it's the serving temp we want to dial in as well isn't it?

 

[egolds77]

The freezer temperature increases at 3 degrees C in 7 mins. I've put a couple more kegs just full of water to increase the cold mass and redure the air space which I'm hoping should help to maintain the temperature better.

I have moved the temp probe to between 2 kegs and closer to the bottom of the freezer. Will see if these 2 changes help.

 

[GTS350]

... put a couple more kegs just full of water to increase the cold mass and redure the air space which I'm hoping should help to maintain the temperature better.

I have moved the temp probe to between 2 kegs and closer to the bottom of the freezer. Will see if these 2 changes help.

+1 for more thermal mass (and momentum) with water in spare kegs..

Better yet...
-put your temp probe into a spare diptube (or anything alloy that's similar to a keg diptube)
-seal one end of that tube with blu-tack/epoxy/electrical tape/etc, and suspend the temp probe+tube (now called a thermowell) in the spare keg of water.
-Or even if if you have no spare kegs, just use a 3litre or 5litre plastic vessel.

Ive found a 3litre juice bottle, with hole in the lid, plus an airlock grommet to hold the thermowell, works very well. (The Berri ones even have a nice little handle around the neck.)

That way your tempmate/fridgemate is controlling liquid temperatures not air temperatures.
Search "tempmate probe position" in these forums for more info.

Cheers,
Richie

 

[egolds77]

Thanks for that info. I found that topic. Will put the temp probe into container of water to create that buffer effect against air temp swing. The freezer is cycling 10 mins on 10 mins off at the moment and it's driving me mad.

 

[GTS350]

Poor mans Thermowell.
The end of the tube is water proof with some blu-tack plugged in and some red electrical tape wrapped around it.
Home brand apple juice 3 litre.

 

[MarkBastard]

Thanks for that info. I found that topic. Will put the temp probe into container of water to create that buffer effect against air temp swing. The freezer is cycling 10 mins on 10 mins off at the moment and it's driving me mad.

Mate, in my opinion you have something fundamentally wrong with your freezer. If you put the temp probe in some liquid like people have said to do, then you may have better results, but I reckon you won't be causing the root cause of your problem and your freezer will still be doing too much work.

I have my probe sitting in open air and I don't have any fan inside my freezer. Mine would be lucky to turn on once every hour and when it does I would say not for very long.

10 minutes on / 10 minutes off suggests to me the cold is getting out too easily. What are your seals like?

 

[MarkBastard]

Also mate turn the fan off and see if it makes a difference. I reckon if you've got a fan going and your seals aren't perfect you are making a HUGE mistake as it will just aid in blowing out the cool air. I bet if you turn the fan off it will cycle less.

 

[alowen474]

I would have the probe in the air, maybe in a conduit with air holes in it.
Have the fan turn on with the compressor. This will evenly distribute the temp when the unit is cooling. Have the probe in the back corner about 2/3rds the way down.
My thoughts on putting the probe in liquid is you will get an air temp over run during the cooling cycle while it drops the liquid temp. Not so much of an issue in a small volume of liquid.
This will result in a 1 or 2 degree additional drop in your temp once the compressor shuts off as the temperatures balance out.
The freezer should be well insulated and hardly change temp at all over an hour.

 

[MarkBastard]

I would have the probe in the air, maybe in a conduit with air holes in it.

Mine comes through my lid so that hopefully it doesn't touch the sides, but I've thought about making a little plastic cage around it so that it doesn't touch the side of the freezer.

IMO if you want your freezer running at 4 degrees, then set it at 4 degrees and stick the thing hanging in the air. If you want it at 4 degrees but want it to cycle less, then put the tolerance up so that the compressor kicks in at 6 degrees and cools down to 2 degrees or whatever, but no need for liquid.

Different when fermenting of course.