The findings of The COGfx Study showed that in the 24 people studied there was a connection between improved indoor air quality and decision-making test scores. The research team thinks the study findings have important implications for offices and the many other indoor environments where we spend the majority of our time.
In The COGfx Study, the 24 participants reported for work each day at 9 a.m. and were tested only six hours later at 3 p.m. At the end of that short period, substantial improvements in cognitive performance were recorded for the workers in the green building environment versus those in the conventional environment.
In The COGfx Study, the research team specifically tested conditions that are found in office environments, but the general principles apply to all indoor environments. The study found lower cognitive function scores when there were elevated volatile organic compounds in the air, and better cognitive function scores when outdoor air ventilation was increased. Previous research has shown that there can be health benefits from keeping VOC concentrations low and increasing outdoor air ventilation. Now this study found that there may be benefits to cognitive function.
While there are cognitive function studies and extensive research on the influence of common indoor pollutants, fewer studies have investigated objective measures of cognitive function in this type of highly controlled, double-blind study. The COGfx Study findings fill important knowledge gaps in existing research through a test of decision-making capacity in simulated settings.
The research showed that participants in the study exposed to air in green buildings had significantly better cognitive function test scores, particularly in the domains of crisis response, information usage and strategy development. Even higher scores were found in the green building with enhanced ventilation setting. While cognitive function is not the sole determinant of productivity, decision-making ability is certainly an important driver.
The study showed that improving air quality improved the environment for workers. The COGfx Study found the best performance with carbon dioxide (CO2) levels below 600 parts per million, ventilation rates at 40 cubic feet per minute per person, and total volatile organic compounds below 50 micrograms per cubic meter.
A follow-up study by The COGfx Study team found that doubling the ventilation rate in typical office buildings can be reached at an energy cost of between $14 and $40 per person per year, resulting in a $6,500 equivalent in improved productivity per person per year. When energy-efficient technologies are utilized, the study found the cost to be between $1 and $18 per person per year, with a minimized environmental impact equivalent to 0.03 additional cars on the road per building.
Typical office buildings are defined using the Department of Energy Medium Office Prototype – a 53,000 square foot, three-story building with more than 260 occupants – with ventilation rates at 20 cubic feet per minute of outdoor air per person, the green condition used during The COGfx Study.
The research team estimated the energy consumption and associated per building occupant costs for office buildings in seven U.S. cities representing different climate zones for three ventilation scenarios and four different heating, ventilation and air conditioning system strategies.
Ventilation Rate | Austin | Charlotte | San Francisco | Baltimore | Albuquerque | Boston | Boise |
Variable Air Volume | |||||||
20 CFM/Person | $0.00 | $0.00 | $0.00 | $0.00 | $0.00 | $0.00 | $0.00 |
27.6 CFM/Person | $7.14 | $7.29 | $4.58 | $10.42 | $4.16 | $12.03 | $6.57 |
27.6 CFM/Person+ERV | -$0.58 | $0.42 | $6.59 | -$1.53 | $3.77 | -$0.82 | $0.15 |
40 CFM/Person | $23.07 | $23.24 | $15.73 | $32.36 | $14.34 | $37.27 | $20.78 |
40 CFM/Person+ERV | $9.37 | $10.55 | $17.44 | $11.21 | $10.05 | $14.06 | $7.83 |
Fan Coil Unit | |||||||
20 CFM/Person | $0.00 | $0.00 | $0.00 | $0.00 | $0.00 | $0.00 | $0.00 |
27.6 CFM/Person | $7.31 | $8.63 | $8.69 | $12.35 | $7.77 | $15.19 | $9.19 |
27.6 CFM/Person+ERV | -$0.18 | -$3.46 | -$0.05 | -$7.29 | -$0.72 | -$8.35 | -$6.77 |
40 CFM/Person | $19.20 | $22.70 | $22.94 | $32.42 | $20.41 | $39.87 | $24.13 |
40 CFM/Person+ERV | $8.32 | $5.18 | $10.22 | $4.01 | $7.88 | $5.81 | $1.00 |
CFM = cubic feet per minute