Designing for Health: Improving Air Quality in Educational Environments
Places where people congregate lend themselves to the spreading of germs, and schools and campus buildings are no exception. The spread of viruses and other contaminants is possible in groups of any size and the potential increases for larger gatherings with a greater concentration of people. Fortunately, there are design considerations that can help reduce the spreading of germs.
Quick & Simple Ways to Improve Building’s Air Quality
Maintenance: Some simple maintenance can go a long way. Regularly changing filters, wiping down the inside of air handling units, and cleaning coils are ways to improve air quality, and can also extend the useful life of your equipment.
Ventilation: Providing more outdoor air to your indoor spaces through increased outdoor air percentages helps “purge” the rooms through ventilation. One way to accomplish this is by including a control sequence that can be triggered manually or automatically based on schedules. Sequences of operation to consider may range from a slight adjustment in outside airflow to a more extreme approach which includes maximizing the ventilation up to the capacity of existing equipment. Another strategy is to provide ventilation continuously, including unoccupied periods, to “flush out” the building. Both strategies have an impact on energy consumption, so it is important to reevaluate these levels regularly to control costs.
ASHRAE has published a quick-reference guide with helpful checklists to assist facility managers with preparations for reopening after shutdowns during the pandemic.
Filtration: Review existing air handling equipment to determine whether it can accommodate improved filtration. Additional filtration causes higher static pressure, so be sure to verify the fan capacity. If necessary, consult with a filter supplier, an equipment manufacturer, or an HVAC engineer. Minimum filter reporting values (MERV) of 13 or greater are recommended for helping capture airborne viruses. Design features such as including additional space for filters have very little cost impacts during construction but may result in a more rigorous maintenance program such as more frequent filter changes and more expensive filters.
Additional & More Involved Steps
Purification: Consider adding air purification systems, such as Bipolar Ionization or Ultraviolet Energy (UV) systems, to your air handling equipment. Many of these systems can be easily retrofitted into existing air handling systems allowing for wide application without any external impacts to the system. These systems can be effective at reducing viruses in the airstream but can come at a higher cost. GMB has applied these systems for many years and has experience in the design and selection of air purification systems.
Humidification: It has been long proven that maintaining an indoor humidity level between 40-60% reduces the time some airborne illness remain infectious. We mention this with caution, however, because if applied incorrectly to a building with an inadequate or poorly constructed envelope, humidity may cause more harm than good by causing moisture damage and increasing mold growth. Humidity can also be impacted favorably or unfavorably by ventilation with varying outdoor conditions. It is important to consider the net impact of all strategies together.
Want to learn more?Reach out to one of our design professionals
Trent DeBoer is a mechanical designer and Certified GeoExchange Designer. He loves helping clients run their buildings efficiently, and working with them to select systems that are going to work best for their institutions over the long haul.
Ron Snoeyink is a mechanical engineer and Certified GeoExchange Designer. Ron's passion lies in collaborating with owners and facility managers on design as well as the day-to-day operations of their buildings to ensure optmium efficiency.
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