Due to the large portion of time, up to 95 per cent,1 that an average individual spends indoors, the quality of the indoor environment has a significant effect on the health and productivity of employees and other occupants and visitors to commercial buildings. The indoor environmental quality (IEQ) is composed of factors such as space temperature, humidity, noise, lighting, interior design and layout, building envelope, and structural systems. A subset of the IEQ is indoor air quality (IAQ). The factors that define IAQ are temperature, humidity, room air motion, and contaminant concentrations.