A Commercial air purifiers can help an office increase clean airflow when the existing HVAC system cannot provide enough during periods of higher infection risk. The important question is not whether a workplace has an air purifier. It is whether the equipment can provide a measurable contribution to the clean airflow required in the occupied space.
An office may have functioning heating and cooling equipment but still have limited options for increasing clean airflow.
This can happen when outdoor air cannot be increased easily, existing HVAC filtration cannot be upgraded, or heavily occupied rooms have limited air movement. Conference rooms and shared workspaces can be particularly important because many people may occupy the same space for extended periods.
ASHRAE Standard 241 provides a framework for reducing infectious aerosol risk by considering ventilation, filtration, and air cleaning together. It uses the concept of equivalent clean airflow to evaluate how these controls contribute to the required level of air cleaning.
Choosing an air purifier based only on a HEPA label or advertised room size can create a misleading picture of its value.
Facility managers should look at the complete performance information, including:
A unit needs to move and clean enough air to make a meaningful difference in the room. The filter type is important, but it is only one part of the calculation.
The useful question for an office is how much clean airflow an air cleaning device can contribute to a particular occupied space.
ASHRAE Standard 241 includes methods for determining the equivalent clean airflow contribution from applicable in room air cleaning systems. This makes documented performance more useful than a general statement that a purifier is suitable for a certain room size.
The calculation should consider the actual room, occupancy, HVAC conditions, existing filtration, and the proposed air cleaning equipment. A purifier that works well in a small meeting room may not provide the same practical benefit in a large open office.