Studies Show Improved IAQ Leads to More Productivity
By Jim Rosenthal, 11/22/2006
Numerous studies show that improving the Indoor Air Quality will lead to higher worker productivity. Measures to improve IAQ don't cost - they pay!!
In a recent article presented by the U.S. Green Building Council and Building Operating Management David P. Callan did an excellent job of summarizing the studies that have been done in recent years showing that better indoor air quality and comfort leads to higher worker productivity. This is very interesting and important information in that it provides us with the ammunition to support the thesis that measures such as improved filtration, better ventilation and the use of ecologically sound building materials actually result in monetary savings for the building owner or tenant. There are seven studies that highlight the potential productivity gains resulting from better IAQ and comfort.
Study #1: In a survey of 100 U.S. office buildings, 23 percent of office workers experienced frequent symptoms of Sick Building Syndrome (SBS) such as respiratory ailments, allergies and asthma. The impact has been usually hidden in sick days, lower productivity and medical cost, but the economic impact is enormous, with an estimated decrease in productivity around 2 percent nationwide, resulting in an annual cost to the United States of approximately $60 billion.
Study #2: William Fisk from Lawrence Berkeley National Laboratory was one of the early researchers to examine IAQ effects on health and productivity. In a recent article, he established a baseline for quantifying benefits from improved IAQ and demonstrated the economic impacts of increased productivity. Findings are showing improvement in IAQ can: Reduce SBS symptoms by 20 to 50 percent, with estimated savings of $10 to $100 billion. Reduce asthma by 8 to 25 percent, with estimated savings of $1 to $4 billion. Reduce other respiratory illnesses by 23 to 76 percent, with estimated savings of $6 to $14 billion. Improve worker productivity by 0.5 to 5 percent, with estimated savings of $20 to $200 billion.
Study #3: A recent study by Bjarne Olsen, chairperson for the International Center for Indoor Environment and Energy (ICIEE) in Denmark, indicated that improved thermal comfort, reduction of indoor pollutants and enhanced ventilation rates and effectiveness can increase productivity by 5 to 10 percent. Conversely, the research also indicates that a 10 percent decrease in tenant satisfaction with IAQ results in a 1 percent drop in productivity.
Study #4: Pawel Wargocki, also from the ICIEE, conducted three separate studies showing an increase of productivity of 5 percent or more through IAQ improvements.
Study #5: In Finland, researcher Olli Seppanon, from the Helsinki University of Technology, developed a conceptual model to estimate cost effectiveness based on improved indoor environment. The model shows a decrease in performance by 2 percent for each degree increase of space temperature between 77 degrees F and 89.4 degrees F. Optimal productivity performance was found to occur when the space temperature was 72 degrees F..
Study #6: Shin-Ichi Tanabe from Waseda University in Japan published findings on effects of thermal comfort on task performance and fatigue. The study was related to office spaces with moderately high temperatures. In Japan, it is recommended by law that office building thermostats be set at 28 degrees C (83.4 degrees F) in the summertime. The study showed that productivity dropped by 2.1 percent when the average indoor temperature increased by 1 degree C (1.8 degrees F). This study also found that individual air velocity control was able to reduce the perception of mental fatigue by the workers.
Study #7: In a recent study conducted by Allan Hedge of Cornell University, low temperatures in the workplace also have a negative impact on productivity. His findings show that "chilly workers not only make more errors, but cooler space temperature could increase the hourly labor cost by 10 percent."
Clearly, potential productivity gains cannot be projected the way that energy savings can be. But research strongly suggests that the investment in better IAQ and comfort pays off in occupant productivity.
Study #1: William J. Fisk, "Health and Productivity Gains from Better Indoor Environments" in The Role of Emerging Energy-Efficient Technology in Promoting Workplace Productivity and Health, a report by Lawrence Berkeley National Laboratory, February 2002.
Study #2: William J. Fisk, "How IEQ Affects Health, Productivity," ASHRAE Journal, May 2002.
Study #3: Bjarne Olsen, "Indoor Environment - Health, Comfort and Productivity," Clima 2005 Lausanne, 8th REHVA World Congress, Switzerland, Oct. 9-12, 2005.
Study #4: Pawel Wargocki, "Making the Case for IAQ," ASHRAE IAQ Applications, Fall 2002.
Study #5: Olli Seppanen and William Fisk, "Method to Estimate the Cost Effectiveness of Indoor Environments in Office Work," Clima 2005 Lausanne, 8th REHVA World Congress, Switzerland, Oct. 9-12, 2005.
Study #6: Shin-Ichi Tanabe, "Productivity and Future HVAC," Clima 2005 Lausanne, 8th REHVA World Congress, Switzerland, Oct. 9-12,2005.
Study #7: Alan Hedge, "Linking Environmental Conditions to Productivity," Eastern Ergonomics Conference and Exposition, New York, June 2004.