Thanks Anthony - quite an interesting read. I used to work at an air force base where they had some of the hangar roofs painted with a heat resistant paint. The guys working inside them said it seemed to make the hangars cooler in the fierce summer heat.
We had our roof at home painted with the same paint and again, some 3 years on, the house does seem to be cooler on those hot, sunny days compared to the inside climate before the paint was applied. No empirical data unfortunately, just the perceived relief of a cooler home, by some 2 or 3 degrees.
