I don't have a good south facing surface on my house, expect on the roof. so for testing purposes, I've built an insulated window port I can connect 6" insulted hoses from the panel on a support in the back yard to the house. I'm heating my computer room in my basement. The heat pretty much goes straight up through the floor into the master bed room. I found both rooms get pretty warm, so what I did in the basement is install a thermostat, and boost blower on the inside wall of the house. When it gets too hot in the computer room, the fan sucks air from the rest of the unfinished basement, and blows the hot air from the room across the basement floor. That cement has plenty of thermal mass. Of course if the forced air furnace comes on because it's cold in the living room and kitchen then all that solar heat is rapidly re-distributed to the rest of the house. When the panel is running the furnace won't run as often, or as long. In the spring, the furnace hardly runs at all, and my panel is just as test, and has had some aging problems that need to be addressed in version 2.