Indoor air quality (IAQ) depends on the building usage, applied ventilation solutions, building location, construction methods and materials, and outdoor conditions. Adequate ventilation and healthy structures are prerequisites for good indoor air quality.

Human comfort, productivity, and a sense of health and well-being are the positive outcome of a healthy indoor environment. Human comfort depends on an interaction of multiple variables. Optimizing both temperature and relative humidity satisfies the comfort requirements for a wider variety of occupants than optimizing only temperature. Carbon dioxide (CO2) level is a surrogate measurement for indoor air quality and human presence.

Vaisala offers a variety of hand-held and fixed instruments for measuring CO2, relative humidity and temperature.