A recently published ASHRAE technical paper was issued to inform and educate consultants, architects and facility managers on mitigating airborne infectious diseases in educational facilities / classrooms provides the following strategy for HVAC systems.
These guidelines are provided in an ASHRAE Position Documentation on Airborne Infectious Disease in HVAC Applications, August 2020 and ASHRAE Epidemic Task Force Schools & Universities (Updated July 17, 2020). These documents can be found at www.ashrae.org/covid19