Hi Andrew,
The cool room does both, fermentors and kegs. Its ussually set at maintaining around 8c for serving beer, with this temp i can ferment lager in there with no probs and ferment ale by keeping a eye on it and heating it up a bit with a heating belt or take it out of the cool room for awhile.
Last summer i was just ussing it for fermenting ales with it set at 16c but now i have retired my keg fridges and put the taps on the cool room.
During winter the aircon hardly ever turns on with some days it actually being warmer in there than out!
Summer times a different story though as it is in the sun at the moment.last summer i measured top temps of 65c with a thermometer placed on top of it.
Iam looking at putting some castors on it and making it easily moveable while still full. Also this summer i plan on bringing it into the shade which may save me a few dollars on power.