“What is IAQ?”; Indoor Air 2006; 16: 328–334
by (late) P. Ole Fanger, Technical University of Denmark
One of the late Professor Fanger’s last papers summarizes Indoor Air Quality (IAQ) from historical to current time (as of 2006). His paper is an excellent compendium of IAQ effects and the different manners in which our health and well-being are affected. The paper can be broken into three main discussion areas; historical background of IAQ, health and productivity examples of IAQ, and methods for improving IAQ beyond today’s standard practice.
Professor Fanger begins the paper with a discussion of air quality metrics and today’s ventilation standards. Our current ventilation standards are based on the fresh air flow rate dissatisfies 20% of the population! With modest improvements of ventilation air flow, significant improvement in health and productivity can be realized without significantly impacting building energy performance. He notes that a small fraction of the populace has air quality sensitivities that require one to two orders of magnitude increase in air flow, but the bulk of the 20% of dissatisfied populace along with the 80% of the not dissatisfied populace can be significantly improved.
Two direct areas of human effects, health and productivity, are discussed by Professor Fanger with examples provided. In terms of health, the increase of asthma and allergenic afflictions since the 1970s appear to be due to better sealed buildings coupled with a new generation of materials used in building construction and for indoor furnishings. Data from a large scale allergy and asthma study in Scandinavia (11,000 children) show strong correlation between ventilation air flow and allergic symptoms, and strong correlation between phalate (a “plasticizer” additive to polymers) concentration and asthma.
Fanger cites two studies in which employee productivity and student test performance correlate with fresh air ventilation rates. The cost of productivity degradation due to low fresh air ventilation significantly outweighs the cost of a building’s total energy cost with the cited articles showing 6 to 9% decreases of worker productivity due to reduced ventilation airflow. In schools, an increase of 15% in test scores was found as ventilation rates increased from 5 to 10 liters per second per person (10 to 20cfm per person).
Professor Fanger ends the article with suggestions for improving air quality in addition to increased fresh air ventilation. Reducing pollutant emissions from building materials and furnishings is a high priority with his suggestion that current 0.1 Olf/m2-floor to 0.02 Olf/m2-floor. Note that 1 Olf is the pollutant loading of a clean clothed, recently showered human with normal office activity metabolism. Even better, he suggests building materials that might absorb VOCs, which we are now seeing enter the market (eg, CertainTeed AirRenew, a VOC absorbing drywall). New technologies for “cleaning” indoor air and providing “personal ventilation” are potential methods for further increasing air quality without excessive energy requirements. Finally, he ends by suggesting a paradigm shift in which we change from “acceptable” air quality to “truly exceptional” air quality that is as fresh and as pleasant as the outdoors. Let’s start today!
The paper can be found at the following link: http://onlinelibrary.wiley.com/doi/10.1111/j.1600-0668.2006.00437.x/abstract
