This article presents useful ancient energy technologies that have been used many years for natural cooling of buildings during summer in a hot and humid province in the South of Iran. By use of these technologies, people were able to live in comfort without any electrical air conditioning system. These technologies include use of color glazed windows, wooden windows frames, light colored walls and roofs, insulated walls, wooden roofs covered with leaves and mud. In addition, these technologies made use of terraces, use of louvers, constructing the lanes as narrow as possible and shading the buildings with the nearby buildings, all of which are now the modern experienced technologies. (C) 2008 Elsevier Ltd. All rights reserved.