Imagine you’re walking across a black asphalt parking lot on a hot summer day. Not very pleasant, is it? The asphalt spends the day absorbing heat from the sun, and that heat radiates upward, making a hot day even hotter. The same thing takes place on your roof throughout the summer, and with worse results. On a sunny day, black asphalt roofing shingles can reach temperatures more than 80 degrees higher than the air temperature, and this heat penetrates your living space. Switching to a “cool roof” with shingles that reflect rather than absorb the sun’s energy can stop this heat transfer, resulting in dramatically lower energy bills–up to 40 percent lower.