You are right about the heat for sure (other stuff too). I am recycling the heat my grow room produces. I have the cool tubes for my HID lighting plumbed into the basement. It surprised me just how much heat it adds. If I could only store it for later, so when the household heat is off or down I could use it. Thought of some type of storage like I had in a south facing room. I had 40, 5 gal water cans made of black plastic that would soak up the sunlight and radiate heat all night! It was pretty cool how well that worked, Oh well it would take up too much precious grow space!