As we continue to manage life alongside COVID-19, there comes a time to brave crowded indoor spaces again. For building managers and administrators in higher education, this societal re-entry to the great indoors requires careful attention to indoor air quality (IAQ).
With ageing HVAC, inefficient ventilation, and even some well-meaning but ill-performing short-term fixes widely marketed to address IAQ, it seems hurdles are everywhere in the face of an airborne pathogen. Infection rates soar in closed indoor areas with insufficient ventilation, and as the virus mutates and becomes more infectious, building administrators are clamouring for better solutions.
One extreme, if common, solution deployed in higher education settings is the replacement of HVAC systems for more modern infrastructure with better air filtration. This wholesale approach to improving IAQ can be time- and resource-intensive, driving some administrators to seek smaller-scale, portable air filters to save time, resources, and space.
However, not all portable filtration systems are created equal, and significant variability in IAQ can be a huge safety challenge in the age of COVID-19.
According to a survey of 500 higher education workers in the U.S., no less than 78 per cent of schools upgraded their HVAC systems to improve filtration. However, only 40 per cent deployed portable HEPA filters, despite these being vastly less expensive and significantly more efficient air purifiers. Perhaps most regrettably, 14 per cent of respondents implemented ionization solutions that are under increased scrutiny from researchers for not being effective.
Though we now have accurate knowledge of how SARS-CoV-2 is transmitted, and the tools to defend against it, many universities are still struggling to determine the best course of action regarding IAQ. What is most effective, what makes the most sense for a specific space, and what can be deployed efficiently must all be balanced in the final safety equation.
RELATED: 3 ways schools can address poor IAQ
Identifying relevant specifications
Effectiveness can be difficult to ascertain if you focus too much on marketing terms commonly deployed within the air quality product sphere. It is all too commonplace to see terms like CFM, HEPA, and 99.99 per cent in isolation, but understanding what these specifications mean in context is the key to selecting the right product for the job.
The air purification industry on the whole does not make this calculation easy. Dr. Jeffrey Siegel, an engineering professor at the University of Toronto, estimates these products to be 50 to 75 per cent illegitimate. “You’re dealing with an industry that doesn’t want consumers to understand these devices and how they work,” warned Siegel recently.
Take HEPA specifications, for example. It’s tempting to base a buying decision on the efficiency of the filter. However, the efficiency of the entire system will determine how well the equipment performs. To evaluate efficiency, pay attention to Clean Air Delivery Rate (CADR), which reflects the airflow measured in cubic feet per minute (CFM) multiplied by the efficiency of the entire system.
What use is having an efficient HEPA filter specification and high CFM, if a significant percentage of the airflow is not running through the filter? If the CADR is not within one per cent of the CFM on a product’s specification, beware. The solution will not deliver the expected Air Changes per Hour (ACH).
Approaching IAQ in a space-specific manner also requires savvy administrators to be wary of new technology that makes bold claims about safety yet has very little real-world evidence to back these claims up. Always prioritize solutions that have been proven to be efficient in operational conditions that mimic the exact environments in which they will be used (an office floor, a classroom, a training centre, etc.).
Another key consideration is the efficiency of the solution for your bottom line: the cost of ownership of these devices, which includes filter costs. The annual consumable replacement costs can be 50 per cent of the upfront machine cost. Many consumer-grade filters get clogged every few months and so need to be replaced multiple times per year. This is not only costly but a significant maintenance headache. Driven by COVID-19, industrial specification HEPA solutions that are designed for professional workplaces are now available. These systems are 99.99 per cent efficient and require filter changes only every one to two years.
Buyer beware: without considering effectiveness, your space needs, and cost efficiency together, it’s easy to make a high-profile mistake. The disappointing recent purchase of HEPA units by NYC Schools cost at least US$43 million, yielding devices that ultimately were “definitely underpowered,” in the words of Dr. Siegel.
Bottom line
Universities that have been sitting stagnant for over a year due to COVID-19 are starting to bustle again with activity. It’s more important than ever to keep students, staff, and the larger community healthy by improving IAQ in the buildings they use every day. Portable, professional-grade air cleaning systems are a powerful tool to help us achieve this, but we need to educate ourselves and better understand whether or not these devices are truly working. Cutting through the misinformation will deliver clean and safe air, helping everyone breathe more easily.
Paul de la Port, CEO of Omni CleanAir, has been delivering commercial-grade air purification systems to eliminate airborne illnesses in office buildings, schools, hospitals, and nuclear power plants for over 35 years.
