Indoor air quality encompasses such factors as maintenance of acceptable temperature and relative humidity, control of airborne contaminants, and distribution of adequate ventilation air. It requires deliberate care on the part of the entire project team. Achieving thermal comfort begins with good design and continues with proper building management and seeks to avoid uneven temperatures, radiant heat gains or losses (e.g., from window areas), draftiness, stuffiness, excessive dryness, or high relative humidity (that can promote growth of mold). Through careful selection of materials, designers can avoid introducing potential pollutant sources. Mechanical engineers and allied trades-people must select and install reliable ventilation systems that dilute the by-products of occupant activities and, to the greatest extent possible, supply fresh air on demand in the right quantities, in the right locations. During construction, air passageways need to be protected and mechanical systems must be balanced and commissioned to achieve optimal operation. Facility managers and custodial and maintenance staff also play a role in keeping areas clean while minimizing the use of irritating cleaning and maintenance supplies.
Even if all objectives are met, attaining an indoor air quality that’s acceptable to all may be difficult, owing to the diversity of sources and contaminants in indoor air, occupant perceptions and individual susceptibility.