Geary Pacific Supply

Ventilating Schools for Safe Reopening

Posted on Monday Apr 12, 2021 at 10:25AM in General

What can schools do to help reduce the transmission risk of COVID-19? With most schools reopening after some being closed for more than a year, school districts are gathering data on how to open safely. The CDC recommends addressing ventilation as a step toward safe openings.


Ensure ventilation systems operate properly and increase circulation of outdoor air as much as possible, for example, by opening windows and doors. Do not open windows and doors if doing so poses a safety or health risk (e.g., risk of falling, triggering asthma symptoms) to children using the facility.

While opening doors and windows would be an easy solution, numerous factors play a role in the ability to do so. Excessive heat or cold, wind, allergens, pollution, noise pollution, and safety are all variables that will dictate the ability to open windows or doors. Mechanical ventilation through the HVAC system is a far better option and will remove those variables while providing the necessary ventilation into classrooms.

Recently, ASHRAE (American Society of Heating, Refrigerating, and Air-Conditioning Engineers), and the UC Davis Energy and Efficiency Institute have given guidance on how to set up the mechanical ventilation systems to aid in the safe opening of schools.

ASHRAE Leadership Statement: “Transmission of SARS-CoV-2 through the air is sufficiently likely that airborne exposure to the virus should be controlled. Changes to building operations, including the operation of heating, ventilating, and air-conditioning systems, can reduce airborne exposures.”

I. Increase outdoor air intake.

While the percentage of outdoor air needed to reduce transmission is currently unknown, varying weather conditions will create issues with opening up the fresh air intake to 100%. The better solution would be to increase the amount of air to the space as if it is 100% occupied. This will get necessary ventilation into the space and ensure the HVAC can maintain designed operating conditions.

II. Ensure the correct operation of all ventilation systems and verify every HVAC system can introduce fresh air.

For ventilators that are currently installed, have them inspected by an HVAC professional to determine operation. For systems without ventilators, add economizers or commercial room ventilators. When the HVAC system is not able to be retrofitted with a ventilator, a separate ventilation system will need to be installed.

III. Increase the amount of time the ventilation system runs.

Operate the ventilation systems for a minimum of 1 week prior to building occupancy. Run the ventilation systems for a minimum of 2 hours after buildings are unoccupied to flush the building and ventilate during all occupied hours.

For more information on protecting your school, business, or home, contact the Indoor Air Quality experts at Geary Pacific Supply.

No one has commented yet.
Comments are closed for this entry.