Fan Position In Fermentation Fridge

[stux]

I have a 400L all-fridge upright fridge that I use for fermenting.

It has enough room for two fermenters one above the other.

I also have a heat source (100W light bulb at the bottom) and the cooling coils are at the top. Both are thermostat controlled.

I can get the top half of the fridge to +-1 C of any temperature from 1 - 28C or so. Nice

The problem is that the top of the fridge is a different temperature to the bottom of the fridge, and I would like a relatively uniform temperature.

The situation has gotten worse since I replaced the wiremesh shelf in the middle with a plywood reinforced shelf so I could do 60L brews


So, I'm thinking of putting 1 or 2 cpu fans in the fridge to circulate the air

Has anyone got any experience doing this? Or can suggest where to put the fan or fans?

I'm thinking of making two holes on the back left/right of the middle solid shelf to circulate the air. Possibly putting one 3" or so fan blowing up, and another blowing down. I figure this will create a circular air movement, hopefully moving the cold/hot air around to make the fridge more uniform.

The thermostat sensors are currently in the top half of the fridge.

I guess I would use a phone charger of some sort to power the fans?

I know there is plenty of advice for chest freezer + collar conversion for keg fridges, but what about uniform temperatures in an upright fermentation fridge?

Any thoughts appreciated

Thanks.

 

[hirns]

Depending upon if there was that much of a problem with the wire shelf. If it wasn't that problematic, and if the ply is thick enough, swiss cheese it with a hole saw. Otherwise, I would think that the door side front of the fridge may be warmer so use a up fan hole at the front (one corner) and a down fan at the rear(diagonal corner) as cold air sinks, and warm air rises. I would not swis cheese it myself if using the fans though as I think you'd have a better cicular flow with just the two fan holes.


Cheers

Hirns

 

[JonnyAnchovy]

I've just measured the temperature diff in my new chest freezer set up, and think I probably need to install fans as well. I'm planning on just velcroing them to a side wall, but I'd like them to only be running for 1 min in every 5 or 10. Any suggestions for a simple timer circuit of hackable off-the-shelf solution for this?

 

[Gopha]

Hi, I have just finished setting up a new fermentation fridge with a 12v computer fan. The fan operates when ever the fridge is running, it certainly improves the fridges performance.

My original fridge belonged to my son, who has decided to repossess it as he has bought a new home and requires a beer fridge.

My process is to attach my temp controller probe to my fermenter and during the winter i also use a heater pad to provide any heat that is required. During the warmer months it is not necessary.

Pics attached-Cheers :icon_cheers:

 

[kbe]

I posted this in another thread. They are small, low wattage and come with a fan.

Small Heater.

It worked fine, with the added advantage of a fan to move the air around. Have a look at them, they work better than a light in my opinion and incandescent lights will run out eventually.

 

[mika]

Gopha - Did you wire a transformer into your temp controller output to get the 12v feed for the fan ? Or what's the go there ?

 

[Gopha]

Gopha - Did you wire a transformer into your temp controller output to get the 12v feed for the fan ? Or what's the go there ?

Hi, I just used an old 12volt power supply from a long dead cordless device and used a power board to supply power to it and the fridge, external temp controller turns the power on and off to the power board.

If you have a close look at the external fridge picture you will see the power board hanging on the wall with the power supply plugged into it. :icon_cheers:

 

[mika]

Cool, that sounds like the go. More wires running under the seal of my fridge oh well, it's all for the good of the beer.

 

[stux]

Depending upon if there was that much of a problem with the wire shelf. If it wasn't that problematic, and if the ply is thick enough, swiss cheese it with a hole saw. Otherwise, I would think that the door side front of the fridge may be warmer so use a up fan hole at the front (one corner) and a down fan at the rear(diagonal corner) as cold air sinks, and warm air rises. I would not swis cheese it myself if using the fans though as I think you'd have a better cicular flow with just the two fan holes.


Cheers

Hirns

I'm thinking of going with the fans diagonally opposite like you suggest. I don't really want to swiss cheese the shelf as the reason I built this shelf was for strength


Re: Power Usage and Heating

Interestingly, I measured the fridge power usage yesterday, its about 100W when its cooling... and it'd be 100W when its heating, I like the symmetry , the 100W incandescent is actually a spotlight, which I think will be around for a while, CFLs don't work very well in frequent on/off applications, like motion activated spots.

Over the last 24hrs it used .1 KWh (2c?)

Which works out to about 8$/yr

I'll actually leave the meter on it for a longer period, I think work out the exact KWh usage for a whole lager ferment