Fans in Fermatation Fridge

[Gunge]

My sensor is taped to the FV at the midway point, heavily insulated from the air by aluminium foil overlaid with an inch of foam. It can't measure anything but the temp of the FV wall, right?? Before anyone gets huffy and starts copying and pasting from advanced thermal physics textbooks etc, I'm not actually all that bothered so long as it's 'thereabouts'.

 

[Bigcol49]

So glad I asked now!! Beginning to think that, stuck to the fermenter, or hanging in the air, the difference may be minimal and certainly not worth getting excited about. I will experiment.

Hi!
I think it's a case of, "Stick it where you want" (as the actress said to the bishop).

 

[3FJ]

The bulb in said fridge...is it perchance 5v? Could you plug a basic PC fan or even laptop fan into that? Anyone? Then obviously disable the door button.

 

[Saisonator]

Maybe handy in a larder sized fridge but waste of time,effort and money in an under counter one.

 

[Saisonator]

Thanks for all the input. It seems the jury is out on this one. It all started when I went to mount the heater on the floor and realised it was right under the fv and was concerned it may cause a local warm spot. Because I have an old pc in the loft with a fan, I think I am going to fit one. Got to get it made now as the new Brew Devil arrived Monday and it keeps calling me to fire it up. LOL

Heat rises and so will circulate, there will be no warm spots, if it's an under counter sized fridge don't waste your time.

 

[Dutto]

........... The air will have to rise several degrees to get enough energy into the wort to increase the temperature. It will also have the potential to cause an overshoot in temperature triggering cooling. .........

Sorry, but I disagree.

Apart from a quick 5 second peek into the fridge at 24 and 48 hours, I DO NOT open the door of the fridge for two weeks! I monitor the temperature of the wort, generally start fermentation at 19*C and then wind it up in 0.5*C steps to 21*C over the first week.

Apart from when making the changes, whenever I have checked the measured temperature of the wort, it has always been within 0.2*C of the Set Point. (Thank you Inkbird!)

I always reckon that the fact that I don't keep opening the door every five minutes gives the Inkbird time to settle down and level out any hysteresis that may occur.

 

[Saisonator]

Lots of domestic fridges do now have fans, ours does and it's not that Posh or Expensive but it is less than 2 years old.

I don't know if one is required in a Fermenting Fridge/Chamber as I'm far too new to brewing but I do know that temperature in my Beer fridge I have out in my shed has difference of almost 3ºc from the top to the bottom some days, maybe test your fridge and add one after if you think it is needed.

You will probably find the fan's purpose is to draw cold air from the freezer below because the fridge does not have it's own dedicated cooling system.

 

[Saisonator]

So glad I asked now!! Beginning to think that, stuck to the fermenter, or hanging in the air, the difference may be minimal and certainly not worth getting excited about. I will experiment.

Definitely stuck to the fermenter, this way you will never get enough significant overshoot to cause the Inkbird to switch from heat to cooler or visa versa.

 

[Honk]

However I am not so convinced at using the temperature of the wort to control the fridge. There is a lot of thermal inertia in the wort and when the wort calls for heat the air temperature in the fridge will rise in order to meet that need. The air will have to rise several degrees to get enough energy into the wort to increase the temperature. It will also have the potential to cause an overshoot in temperature triggering cooling. If you measure the air in the fridge, it has a low thermal inertia, temperature corrections will be small and fast. The temperature of the air will be relatively stable and the temperature of the wort will follow suit - albeit sometime later.

I see what you are saying and I expected the same thing but my current fermenter has a thermowell so is measuring the wort temperature. I was surprised how little overshoot there is maybe 0.2 Deg c when ramping up and down not enough to trigger the fridge to come on when heating or vice versa.

No fan for me