While much of the focus in the AEC industry is focused on healthcare related facilities right now, it’s important to keep in mind all of the other buildings that have been or will be occupied as various restrictions are lifted. Most educational facilities have closed their doors for the summer, however in a few months thousands of students and teachers could be back in traditional education buildings. What should we be doing in those facilities to help mitigate the potential spread of viruses and germs?
A quick look at design strategies for healthcare facilities provides several potential solutions for retrofitting infection control into traditional classroom spaces.
Airborne contaminants can be eliminated or reduced by modifying the building’s HVAC system. Traditional VAV HVAC systems recirculate a large portion of air that was previously delivered to the space.
If an economizer is available it should be used as much as possible or for extended outdoor conditions, even if mechanical heating or cooling is needed, so that the system can operate in 100% outdoor air mode. This will prevent the recirculation of contaminates from the space.
For systems that utilize dedicated outdoor air units with energy recover wheels, the wheel should be bypassed as much as possible to prevent cross contamination.
For small unitary systems, systems that do not have an economizer, or for when outdoor conditions are not favorable, UVGI lights can be installed in the fan coil and air handling units. The lamps should be sized to disinfect not only static surfaces as they are traditionally used, but the dynamic airstream as well. The added benefit of this system is that if located properly it will help keep the cooling coil clean which will reduce pressure drop and associated energy consumption.
In summary, most education buildings utilize HVAC systems that reduce indoor pollution through dilution. This however is not effective for airborne viruses. The best way to prevent the spread of airborne viruses is through elimination which can be achieved by providing 100% outdoor air or killing biological matter within the airstream.
Seth P. Spangler, PE, LEED AP, BD+C, BEMP
Southeast Market Leader