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Ford’s #FinishStrong Initiative is sharing an inexpensive open-source design for a fan and HVAC filter combination that could help reduce virus particle concentrations in enclosed spaces, such as classrooms and shop spaces. Easily assembled, the COVID-19 air filtration box fan solution developed by Ford is an air filtration solution that people can make at home or in a school. This may be a great supplemental solution for theater educators and theater makers to use in shops and classrooms.
The filtration solution is comprised of an easy-to-assemble die-cut cardboard base, a 20-inch box fan, and a 20″ x 20″ x 4″ air filter with a standard minimum efficiency reporting value of 13. The air filter is placed inside the folded base with the fan placed on top. The fan operates on high for maximum filtration, discharging clean air downward as it pulls in unfiltered air from above. Ford is making the design available free. The instructions are downloadable here and at the end of this article. An empty home delivery box can serve as the base (see direction images at end of this article). A 20″ box fan and a 20″ x 20″ x 4″ air filter are easily purchased through a home improvement and tools retailer like Walmart, Home Depot, or Lowe’s as well as through Amazon.
Ford’s COVID-19 air filtration box fan solution supplements a room’s existing filtration system to further help reduce the risk of COVID-19 virus particle concentrations. The box fan solution is based upon scientific studies from academic and government research. Because COVID-19 can spread through droplets when infected persons exhale, cough, sneeze or talk, Ford conducted smoke particulate testing of the air filter at an independent test lab using the industry standard AHAM AC-1 test. These tests show that the unit provides a clean air discharge rate of 213 cubic feet per minute.
Ford and the University of Minnesota conducted aerosol modeling studies in a classroom-sized space that show increasing air filtration in closed spaces helps reduce particulate concentration, which includes aerosols and droplets. “Our modeling results clearly show that improvements in air filtration of poorly ventilated spaces through the proper use of a portable air cleaner can help reduce the chance of breathing in contaminated aerosols,” said Dr. Jiarong Hong, mechanical engineering professor in the University of Minnesota’s college of science and engineering.
The impact of the portable air cleaner unit depends on where it’s placed and the size of the room. Ford studies show that with a room size of approximately 960 square feet (31’ x 31’), similar to an average-size classroom, adding two portable air cleaner units can triple the air changes per hour compared to what a building HVAC system alone would clean, refreshing the air 4.5 times per hour.
Downloadable instructions: How to Assemble a COVID-19 Air Filtration Box Fan
Photos of how to assemble the cardboard box base:
