The roaster is an oven of sorts so the drum is throwing off heat. But will it be on for 8 hours a day?
How big is the room?
It will raise the surrounding temp a bit but to a point of sweltering!
I have a large area so I cannot say how much of a difference, but I run mine for about 3 hours and in the summer with the door open I really do not see any difference.
I have 4 roasters from 120 k down to a 2 k...it used to get warm until we put in 2 huge air units dedicated to the roastery only! I used to have a place I roasted for that was a retail environment. I had a 5 kilo roaster and the whole shop was about 500 sq feet including storage. I had no issues with heat. We did have a problem with smoke when we did our French roast though..it would smoke the whole place out!