2 carboys actively fermenting raises chamber heat too much?

[Ted123]

Hi all,
I have a fermentation "closet" I built, with a heat mat and a temp control gauge. In this recent IPA, I set the gauge to 65, and then placed two 6.5 gallon carboys in, one with Vermont ale yeast and the other with London/1028 . . . . And the active first stages of fermentation cranked the temp in the chamber up to 74!

I guess the heat mat probably never even kicked in . . . I even lowered the temp gauge to 62 in an effort to cool it down in there a bit, and swung the door open now and then to introduce cooler air.

Can two carboys crank out too much heat as they "free rise", and should I maybe think about only one carboy at a time, or maybe building a bigger chamber so there is more air space around each carboy? (Right now the chamber is roughly a four foot cube)?

Thanks . .

 

[ABVIBUSRM]

dont worry about the vermont yeast it does well at higher temps..i did a batch and finished it at 74 it was fine..i think you should watch this video and incorporate it into your chamber to give you a cooling option

[ame]https://www.youtube.com/watch?v=HxSLbpAwibg[/ame]

 

[wardens355]

I think your experience has answered your question. Fermentation produces heat - more vigorous, higher rate of heat production. Without any cooling method, the temperature will likely always exceed the setpoint for your system if it is in an enclosed chamber with any sort of insulation.

 

[Beernik]

Yes. I had two 5 gallon lagers fermenting in a freezer in a detached garage last January. The two fermenters managed to generate most of the heat they needed on their own to maintain 50F in the freezer even though the garage temp was in the 30Fs