1.   Do not include the basement in your calculations because the fan will only cool those rooms above ground level.

2.   Their house was completely gutted, including the basement, which they deepened by a foot and a half and fitted with a large playroom.

3.   Then, probably most importantly, pull open all drapes and turn on the lights in every room, including the basement.

4.   Most homes in the area were built on three levels, including the basement.