My basement is 2/3s buried and 1/3 exposed and has a garage car door that is used daily. The floor of the southern end is 8 or 9 foot below the ground level. The wall is uninsulated concrete block. It has been up in the 70s for 10 days and the basement is already between 64 to 68 degree air temp and rising.Itwas 50 a month ago. I was thinking about geothermal cooling. A box has 6 sides. What if you built a box out of insulation board with 3 sides? The floor, the back wall and the end wall is missing. You place the box in the corner so the basement floor is the floor, and the concrete block wall forms the missing walls. Let the cooler temperature of the earth provide the cooling. Has anyone tried this? I vaguely remember something like it is always like 60 degrees 10 feet below the ground level.