Do I Really Need An Air Purifier?

March 18, 2021
BGE Indoor Air Quality Solutions

It is not uncommon these days to hear water cooler or dinner table talk turning to the subject of COVID-19 and Portable Room Air Purifiers. These are relevant and closely tied topics that seem to be on a lot of people’s minds.

Before we dive into the pros and cons of different room air purifiers for commercial applications, I’d like to start at the beginning and answer the question that is on many minds right now: Do I need a portable room air purifier, and will it really help reduce the risk and spread of COVID-19?

Unfortunately, the answer is not simple or absolute. But I’ll do my best to help you navigate it with more clarity.


Let’s start by defining what a Room Air Purifier is.

A room air purifier is a compact, standalone device that removes (captures, destroys, alters, knocks out) airborne contaminants (undesirable particles, microbes, odours) in a room (a defined space with imperfect boundaries like gaps and openings).

Room air purifiers come embedded with multiple technologies, but the gold standard component in the vast majority of air purifiers today undoubtedly is the HEPA filter. A “true” HEPA system will effectively capture COVID particles, to as much as 99.97% give or take a few 0.01’s, no matter their size in aerosols or in the air.

That being said, there are also other technologies that can be stand-alone or complementary to the HEPA filter in an air purification system. More to come on that in a separate post.


A Room Air Purifier should augment your existing system.

Room air purifiers alone are not robust enough to ventilate a large space, but there are certain conditions that make them an ideal complement to your existing ventilation and HVAC systems:

  • If contaminants are unacceptably high, based on measurement, assessment or perception
  • If changes to your overall ventilation and HVAC systems aren’t enough to get you to your end goal, or aren’t feasible or warranted or cost-effective otherwise
  • If a careful assessment of your situation tells you there’s a worthwhile measurable or calculated benefit

If you ask authorities, you will get a fairly clear answer on whether or not Room Air Purifiers can help improve your indoor air quality overall.

According to ASHRAE’s Position Document on Infectious Aerosols:

  • “When appropriately selected and deployed, single-space high-efficiency filtration units (either ceiling mounted or portable) can be highly effective in reducing/lowering concentrations of infectious aerosols in a single space.”
  • Add portable room air cleaners with HEPA or high-MERV filters with due consideration to the clean air delivery rate (AHAM 2015).”

The CDC also published official guidance pertaining to the use of room air purifiers:

Infection prevention and control (IPC) practices during the COVID-19 pandemic:

  • “Explore options to improve indoor air quality in all shared spaces.”
  • “Optimize air-handling systems: ensuring appropriate directionality, filtration, exchange rate, proper installation, and up to date maintenance.”
  • Consider the addition of portable solutions (e.g. portable HEPA filtration units) to augment air quality in areas when permanent air-handling systems are not a feasible option.”


So, do I need a Room Air Purifier?

We haven’t really answered the question yet, have we? Let’s see if we can give you a more definite answer. The real answer is that we can’t definitively tell you whether or not you need a Room Air Purifier; no one can, without seeing your space and understanding your goals. But we can help you towards an answer by giving you some good questions to ask.

To help you determine whether or not you need a Room Air Purifier, we recommend that you do a proper assessment of your space. You can do this yourself, or seek out some expert to help you (shameless plug – we do that here at BGE!) to answer these questions:

  • What is your indoor space used for? Who accesses it regularly and why?
  • How many people – workers, customers, etc. – generally occupy the space, and for how long at a time?
  • How much outside air is getting into the space? And what is the quality (and filtering/purifying) of any recirculating HVAC air into the space?
  • Can I otherwise implement practical and cost-effective changes to my ventilation and HVAC systems that will go a long way towards answering my concerns and fulfilling my goals?
  • What are air flow patterns in the space? How will they change with the addition of an air purifier(s) – improved or worsened? Where would/should I put the air purifier(s) in the space for best benefit?
  • What is my budget and is it realistic enough to obtain a system that can be calculated or demonstrated to be a big enough improvement and best bit specifically for my space?

Adding an air purifier(s) to a space improperly may not help at all, and could even make things worse if it causes degraded air flow patterns! By answering these questions, you can determine with confidence whether or not a Room Air Purifier will add to your indoor air quality, and you can start thinking about features, budget, and placement of your units to complement your existing indoor air systems.