What is Natural Ventilation

Southern European areas are traditionally considered to have a benign climate and therefore most homes often do not have controlled ventilation systems or air conditioning. Our society faces challenging situations with global pandemics and health emergencies, while housing provides the basic elements of refuge and activity. A profound transformation of social and labor dynamics is underway, increasing at-home presence, hence the capital importance of improving building envelopes to reduce energy demand and to increase occupant comfort levels in order to ensure their protective function. Air leakage is one of the key factors both in indoor air quality and energy demand. This study aims to explore the sensitivity of energy demand to airtightness. A representative set of multifamily buildings, built in the last 20 years in Seville, is analyzed. The results show that air permeability has a significant effect on energy demand in the sample studied. Although impact is greater in severe climates, it needs to be considered in temperate climates, especially when more time is spent at home.