Ventilation and Air Distribution Systems in Buildings

The need of building occupants for ventilation has been recognized many centuries ago; however, since the early 1970s, ventilation systems for buildings and transport systems have considerably evolved. This was invigorated by researchers who demonstrated the requirements for buildings to provide comfort and good air quality indoors (e.g., Fanger, 1972; Fanger and Christensen, 1986; Fanger, 1988; European Collaborative Action, 1992). Later on, this need evolved to address the additional energy requirement for buildings to achieve the indoor environment quality levels stipulated by those previous researchers (Awbi, 2003, 2007; Karimipanah et al., 2007, 2008). Energy consumption for heating, cooling, and ventilating buildings often accounts for the largest part of a country’s energy usage, which is still mainly based on fossil fuels. There is a great global emphasis on reducing the reliance of buildings on fossil fuel energy and a move toward Nearly Zero Carbon Buildings (NZCB). This requires a major shift in the way buildings and their integrated heating, cooling, and ventilation systems are designed, operated, and maintained. Achieving this goal will require a rethink of the traditional designs of and types of systems currently in use. The proportion of ventilation energy in comparison with the total energy use in a building is expected to increase as the building fabric energy performance improves and ventilation standards recommend higher ventilation rates for improving indoor air quality (IAQ). At the same time, new building regulations (Directive 2010/31/EC, 2010; Building Regulation, 2010) are imposing air-tight construction, which will inevitably impact on IAQ, health (e.g., sick building syndrome), and human productivity in some future buildings (Seppänen, 2012). Despite recent advances in building ventilation (Nielsen, 1993; Etheridge and Sandberg, 1996; Skistad et al., 2004; Awbi, 2011; Müller et al., 2013), it is evident that complaints about poor IAQ have increased in recent years (Gunnarsen and Fanger, 1992; Fisk, 2000, Bakó-Biró, 2004; Fanger, 2006; Boestra and van Dijken, 2010). There is a need therefore for assessing current methods of building ventilation and developing ventilation systems that are capable of providing good IAQ and energy performance to satisfy building occupants and meet new building energy codes. This article gives a brief overview of the various types of mechanical ventilation and air distribution systems that are used for buildings; highlighting those systems that are capable of providing better IAQ and energy efficiency. The aim is to provide some insight to those building professionals whose tasks are selecting ventilation systems for low energy buildings that can provide the necessary levels of IAQ for the occupants; and for the research community to continue research in this area in order to develop new ventilation concepts and deliver the desired performance.