Natural-cooling techniques for residential buildings in hot climates

In most developing countries in the hot regions of the world during the last 50 years there have been many buildings constructed that are highly energy wasteful. The interiors of these buildings have to be mechanically air-conditioned in order to achieve thermal-comfort conditions. Consequently vast financial expenditures have and are being spent upon the installation and operation of the electricity-generating plants needed to supply the maximum power demand during summer. In many of these countries, air-conditioning accounts for more than 70% of the national electrical power consumption. However, less than a century ago, the inhabitants of these countries lived in buildings that incorporated only natural-cooling (i.e. far cheaper) techniques for achieving thermal comfort. In this paper, these tranditional beneficial techniques have been reviewed and the recent advances in both hybrid and active natural-cooling systems described.