I was at a tiny small market station in e. washington that was in a single story building the size of your average garage in the 70's. The xmtr was on site in the building in a separate room. Yes, a "room". The boss insisted that the fan exhaust heat was adequate to heat the place so we didn't need to turn on any more heaters. It would save money. (Ok, enough of the old fart engineering stories...back to "solid state")..