We are past one of the darkest periods of the 21st century – the disease, death, and social disruption of a novel airborne virus. But the world is always susceptible to other airborne pathogens, even multiple ones striking concurrently.
That’s why health care facilities, as well as schools, homes, and businesses, have welcomed a landmark new indoor air quality standard from the HVAC industry. The new standard provides important guidance for architects, facilities managers, risk managers, COOs, and other leaders to make one’s building safe from airborne transmission of COVID, the flu, and other pathogens.
Nowhere is riskier in this respect than health care facilities with sick people both introducing airborne pathogens and being more susceptible to them. Also among the susceptible are strained health care staffs who are exposed to viruses every day and can’t afford absences due to illness.
ASHRAE 241 – A First
The ASHRAE 241 standard, as it is known, is billed by its creators as groundbreaking and “the first consensus-based, code enforceable standard of its kind.” It details requirements for indoor air to bring disease transmission risk down to one transmission in 1,000 occasions where people share rooms.
It goes beyond existing general standards for ventilation-focused indoor air quality by defining the amount of equivalent clean airflow met by a combination of ventilation, filtration, and air cleaning necessary to substantially reduce the risk of disease transmission during infection risk management mode. That is the operating mode when increased protection from infectious aerosol exposure is needed, such as in the COVID pandemic.
“The COVID-19 pandemic, together with the evidence that poorly ventilated buildings can be high risk environments for airborne infection transmission, brought the adequacy of existing IAQ standards under heavy scrutiny,” writes ASHRAE, formerly known as American Society of Heating, Refrigerating and Air-Conditioning Engineers.
“ASHRAE rose to the challenge of creating a comprehensive, consensus-based, code enforceable standard to mitigate the risk from respiratory pathogens by assembling a committee of international experts that spent thousands of hours in development and addressing more than 1,000 comments received.”
An Ominous Gap In Building Safety
Especially in the early days of the outbreak, the pandemic revealed a lot of ignorance and confusion about what constitutes safe indoor air quality both during an outbreak and in normal times. ASHRAE 241 settles such questions.
The new standard smartly sets out metrics for airflow that can be trusted to make spaces free of infectious aerosols. These metrics account for occupancy count and intensity of use. For example, airflow requirements will be higher for a busy Peloton studio than a quiet warehouse.
Answers Arrive
Finalized last July, ASHRAE 241 was created by 48 international experts working six months straight (a blink of an eye in standards terms). Like any other proposed standard – say, your local fire and building codes – enforcing it requires jurisdictions to adopt it, which is likely.
New standards are generally welcome. Building operators are eager for guardrails and guidance as long as they are reasonable. Owners and operators are especially eager to have a clear, simple pathway to compliance without getting mired in planning and red tape.
How To Comply
The traditional method for pursuing indoor air quality requires a long slog: assessments, planning, research, tables, and calculations based on hypothetical airflow rates, equipment rating, building use, and occupancy levels. You needed to invite (and pay) special assessment teams to validate your design.
A consensus emerged in the writing of ASHRAE 241: Isn’t there an easier way? Can’t we just test the clean airflow directly?
That question arose during standards development, and the writers listened. Critically, ASHRAE 241 allows a speedy yet unassailable end-around for clean air quality validation that’s actually more accurate than the mathematical models. You test the actual air.
As part of ASHRAE 241, a new testing protocol was designed based on the methods that have been used in the aerosol research field. This test uses particle releases into the space and measures the rate at which they’re diluted with clean air.
New Easy Test Arrives
You set up a test area equivalent to 10% of your space. You use a nebulizer to spray particles into the air. If your air tests clean (equivalent clean airflow checks out), you are good. Kits are available to run ASHRAE 241-compliant tests, download results, and have your space certified as compliant.
If you fail, however, you need to ventilate better or clean up the indoor air. The default solution is to bring more outdoor air inside through your HVAC system, which can be expensive, disruptive and time consuming. Other approaches include filtration and advanced ultraviolet devices.
New Revolutionary Technology Destroys Pathogens
One of the simplest and most effective approaches is harnessing the power of oxidation. Unlike HEPA filters that trap but don’t eliminate airborne pathogens, this new technology destroys them.
In this process, UV-C lamps use ultraviolet light convert oxygen in the air (02) to ozone (03). The newly created ozone destroys any microorganisms flowing through the device. The ozone is then converted back into oxygen, which is then reintroduced into the room as clean, fresh air. Virtually no ozone escapes the unit. In fact, testing proves that ozone levels leaving the unit are lower than levels in the ambient room air. Vetted units come in mini size (up to 200CFM,), mobile (up to 310 CFM) and ceiling/wall mounted ( up to 200 CFM).
In independent testing, the technology has achieved a 99.998% reduction of live COVID-19 Delta Variant in a single pass of approximately 1.2 seconds. Efficacy on RNA virus, MS2 virus, and other pathogens has also been proven in independent testing. The technology has also earned 510(k) Class II clearance from the U.S. Food and Drug Administration.
Once your space is deemed compliant, you can document your solution for your building readiness plan outlined in the standard.
At that point, you’ll know you’ll be more prepared than ever. You’re ready for the next pandemic or maybe just better equipped to avoid the common cold and flu.