Indoor Air Quality

Indoor Air Quality

January 30, 2013.

The "green design" movement in the commercial and residential HVAC industry emphasizes paying attention to the issue of indoor air quality throughout the design and construction stages of a buildings' life. One technique to reduce energy consumption while maintaining adequate air quality is demand controlled ventilation. Instead of setting throughput at a fixed air replacement rate, carbon dioxide sensors are used to control the rate dynamically, based on the emissions of actual building occupants.

For the past several years, there have been many debaters among indoor air quality specialists about the proper definition of indoor air quality and especially what constitutes "acceptable" indoor air quality. One technique to reduce energy consumption while maintaining adequate air quality is demand controlled ventilation .Instead of setting throughput at a fixed air replacement rate, carbon dioxide sensors are used to control the rate dynamically, based on the emissions of actual building occupants.

For the past several years, there have been discussions among indoor air quality specialist about the proper definition of indoor air quality and especially what constitutes "acceptable" indoor air quality. One way of qualitatively ensuring the health of indoor air is by the frequency of effective turnover of interior air by replacement with outside air.

In the UK, for example, classrooms are required to have 2.5 outdoor air changes per hour. In halls, gym, dining and physiotherapy spaces, the ventilation should be sufficient to limit carbon dioxide to 1,500 ppm. In the USA, and according to ASHRAE standards, ventilation in classroom is based on the amount of outdoor air occupant, not air changes per hour.