Abstract

Global Warming and Urban Heat Island are phenomena that are worsening the building energy performance, increasing the cooling demand in summer time of any kind of buildings. The development of new codes for construction should have been the main strategy to transform the built environment in a net zero energy sector. However, in many countries a unexpected factor is preoccupying users and designer of new buildings: accomplishing the most restrictive laws on energy savings (principally developed to avoid thermal losses during the cold season), is leading to a substantial overheating of the spaces in summer and in some cases even in winter. One of the best strategies to avoid overheating is the use of natural ventilation, especially where breezes are almost constant during the day and year. This is the case of the long Chilean Pacific Coast, where many of the most important cities of the country are placed. This paper uses a steadystate evaluation method to estimate the cooling demand and the reduction of this demand due to the use of natural ventilation (wind driven). Different building typologies are evaluated in eight cities, from North to South: Arica, Iquique, Antofagasta, La Serena, Valparaíso, Concepción, Valdivia and Puerto Montt. Results are compared with simulations conducted by using the “natural ventilation” module available in Design Builder tool. It is found that in the particular condition of the Chilean coast, at least the 50% of the cooling demand could be eliminated by using accurate natural ventilation systems. It is also suggested that the inclusion of this kind of evaluation in the buildings energy certification system of the Housing Ministry could benefit the entire country in terms of energy demand and greenhouse gases emissions reduction.