posted 11 years ago
I did the very thing, building in the basement, but I didn't couple the heater to the walls. The burn chamber floor is a layer of kiln bricks directly on the concrete floor, so the floor heats up pretty nicely, acting like a thermal battery. After the fire is out, even eight hours later the floor around the base of the heater is still warm.
I keep the heater running all day so the entire basement acts as my battery, then the stored heat just kind of emanates [convection] upwards through the night, keeping the second level around 65ºF even when it's well below freezing outside.