The Dave House South started off performing on par with the Andy Shack, but the unfavorable weather on the 14^th allowed the Dave House South to jump ahead. The Andy Shack loses heat so quickly that its temps fall 15 ^oF in one day, while the Dave House South (protected by its insulation and large thermal mass) only loses 5 ^oF. It is not surprising that the Andy Shack is able to reach higher temperatures than the Dave House South during the day because it has more absorber area per square foot of floor. The Andy Shack has 93.5 ft² of absorber for 77 ft² of floor, while the Dave House North only has 65 ft² of absorber for 252 ft² of floor. The behavior of the two sol-air temperatures confirms the conclusions from the last graph. However, I am unsure what caused the discrepancy between the two on the night of the 8^th.