At the beginning of last year, the National Energy Management Institute (NEMI) and the University of California-Davis Western Cooling Efficiency Center were in the process of creating an industry white paper specific to classroom indoor air quality. Proper ventilation and frequent air changes result in lower carbon dioxide levels and increased cognitive retention and productivity, as well as reduced pathogen levels. When COVID-19 hit, and it looked like children would be learning from home until schools were safe, it was a quick pivot to also include ways schools could prepare their facilities for a safe reopening.
Their findings were based on the recommendations of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Epidemic Task Force, NEMI and the University of California-Davis Western Cooling Efficiency Center.
The following tips were compiled using information in the white paper, and although all clientele should consult a certified testing, adjusting and balancing (TAB) technician, the following items can be shared with them as ways they can put the safety of their indoor air quality into their own hands:
1. Air filters: The Centers for Disease Control and Prevention (CDC) has instructed building owners to use filters with a Minimum Efficiency Reporting Value (MERV) of 13, which means the filter is able to catch 90% of particles in the 1-3 micrometer range and 50% of the particles in the .3-1 micrometer range. Due to the type of filtration, using these types of filters may cause higher energy consumption; however, they are available for residences as well as commercial buildings. Don’t forget to change your filters every 90 days. And, no, a MERV 8 filter plus a MERV 5 filter does not equal a MERV 13.
2. Increase outside air: When weather permits, opening a window or door will increase the outside air, which helps ventilation by pushing out carbon dioxide and increasing oxygen. Those sleepy afternoon study sessions will suddenly seem less drowsy when outside air is introduced. This is an easy and adequate option for a single-family home.
3. Air distribution: Just because fresh air is entering a building does not mean everywhere in the building has adequate ventilation. Ever felt warm in one part of your house but cold in another? That is the result of poor distribution. A skilled, trained and certified Testing, Adjusting and Balancing Bureau (TABB) technician can make sure the system is balanced, which will not only provide even temperatures but also ensure the rooms have proper ventilation.
4. Carbon dioxide (CO2) monitoring: A monitor can be a canary in the coal mine, alerting to a problem as soon as it occurs. Monitors can be ordered online — either hard-wired or plugged-in — and mounted 3 to 6 feet above the floor and at least 5 feet away from doors and operable windows. Displays should be easily readable, or seen through a web-based or cell phone application. It should notify the operator when the CO2 levels have exceeded 1,100 parts per million (ppm). A 2018 report in the Environment International Journal found that short-term CO2 exposure beginning at 1,000 ppm affects cognitive performance, including decision making and problem resolution. The Wisconsin Department of Health states CO2 levels between 1,000 and 2,000 ppm are associated with drowsiness and attention issues. CO2 levels above 2,000 ppm affect concentration and can cause headaches, increased heart rate and nausea, according to the white paper.
5. General maintenance: An improperly maintained unit will result in poor indoor air quality and wasted energy. Call a skilled, trained and certified technician if the unit has dirty or damaged coils; dirty water sitting in the drain pan; or the unit isn’t producing cold air.
Before any changes are made to your system, contact a skilled, trained technician who has been certified by the International Certification Board/Testing Adjusting Balancing Bureau (ICB/TABB). Contractors can be found here. Interested in classroom indoor air quality? Watch this short video.
Originally posted on Eye on Sheet Metal.