A new study finds that doubling the ventilation rate, and thus IAQ (indoor air quality), in typical office buildings can be reached at an estimated annual energy cost of between $14 and $40 per person, resulting in as much as a $6,500 equivalent in improved productivity per person per year. When energy-efficient technologies are utilized, the study found the energy costs to be even lower, with a minimized environmental impact of approximately 0.03 additional cars on the road per building.
The research, titled “Economic, Environmental and Health Implications of Enhanced Ventilation in Office Buildings,” was conducted by the Harvard T.H. Chan School of Public Health’s Center for Health and the Global Environment, SUNY Upstate Medical, Syracuse University, and Carrier.
The report was published in the International Journal of Environmental Research and Public Health’s special issue “Indoor Environmental Quality: Exposures and Occupant Health,” and builds on the recently released “Impact of Green Building on Cognitive Function“ study by the same research team. Also known as The COGfx Study, the research found cognitive function test scores improved 101 percent in green building environments with enhanced ventilation compared to conventional building environments.
Researchers studied three indoor environments achieved by four different HVAC system strategies across seven U.S. cities as outlined below. For each scenario, the team selected the U.S. Department of Energy Medium Office Prototype (a 53,000-square-foot, three-story building with more than 260 occupants) as the standard; used state average utility prices for each city; and referenced salary data obtained from the Bureau of Labor Statistics.
The researchers used Carrier’s Hourly Analysis Program (HAP) to calculate the annual energy consumption for the HVAC equipment. Environmental impacts were then derived using the U.S. Environmental Protection Agency’s Power Profiler tool. At the highest ventilation rate, they found that adding an ERV “essentially neutralizes the environmental impact of enhanced ventilation” — equivalent to approximately 0.03 additional cars on the road per building across all cities. Specific results are dependent upon each city’s individual power generation fuel mix, with researchers noting “the per building environmental impact on greenhouse gas emissions is not as impactful as the estimated benefits.”