On one piece of property we have a portable building (approx. 10ft by 15 ft) and we have a nice size heater in there with two bunkbeds and a table. It is really nice for hunting when it is really cold. Can't shoot a bow out of it, but you can a rifle. We have had that thing running full blast and had several deer at the feeder which is about 25 yards away and the deer didn't seem to be effected. We have been doing this for several years now.