Increased concern over the adverse environmental impact of energy use has encouraged the design and construction of energy-efficient buildings, and many are suited to natural ventilation. In the temperate climates, naturally ventilated buildings can provide year-round comfort, with good user control, at minimum capital cost and with negligible maintenance.

It has been estimated that in countries such as the United Kingdom, natural ventilation could be the obvious choice in 20% of newly built nondomestic buildings. On a purely tech-nical basis, e.g., a deep-plan building in a noisy city center polluted by traffic fumes, approximately 10% may need to be air-conditioned. However, there are also a substantial number of situations (50%-80%) where the choice is less clear cut and where design for natural ventilation requires more fore-thought.

The principle of good ventilation design is to "build tight, ventilate right." That is, to minimize uncontrolled (and, usually, unwanted) infiltration by making the building envelope airtight while providing adequate "fresh" air ventilation in a controlled manner. It is necessary to emphasize that a building cannot be "too tight," but it can be underventilated.

This paper shows that there is considerable scope for making buildings tighter, identifies some of the benefits that can accrue, and provides some summary guidance. On ventilation requirements, provisions necessary to satisfy safety and health criteria are laid out. Strategies developed to address comfort issues, such as summer overheating, are addressed, as well as those perceived in the urban environment, namely, air and noise pollution.

The paper concludes by describing novel designs employed in two key United Kingdom buildings where issues of low energy and urban contamination have been addressed in a stimulating and thoughtful manner.

Authors: M.D.A.E.S. Perera, Ph.D., M. Kolokotroni, Ph.D.
Citation: IAQ and Energy 98: Using ASHRAE Standards 62 and 90.1 Conference Papers
Keywords: October, Louisiana, 1998