Although we are 8 months into this pandemic, there are still so many unknowns and fears that plague our communities. When will life get back to “normal?” How can we stay safe as the weather begins to turn around the country? How does the virus spread indoors? How can we reduce the risks of being indoors?
Unfortunately, it will take time before an approved vaccine is available. And it may take even longer for a vaccine to reach mass distribution before we can accomplish herd immunity and resume life as “normal.” However, there are a few things that we have learned over the past 43 weeks of the pandemic that can certainly inform or educate us on best practices. As most of the country is forced to hold everything indoors, there are many solutions to help mitigate risks and mass transmission of airborne viral particles.
How does the virus spread?
According to Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, we do not know how much virus makes an infectious dose and we do not know how much exposure is required to reach that point. However, the Center for Disease Control and Prevention has stated publicly that the transmission of the virus is through aerosol transmission, making actions like sneezing, coughing, and talking more likely to produce respiratory droplets carrying the virus into the air. Larger respiratory droplets fall quickly due to their weight and will not typically penetrate surgical masks, however, droplets less than 5 microns in diameter, called aerosols, can remain in the air for hours (ASH Clinical News).
What are the risks of being inside vs. outside?
Factors such as proximity to the infected person, air flow, and timing all seem to be critical factors for aerosol transmission. Which is why gatherings outdoors have typically presented less threats when social distancing and mask wearing are also utilized. Multiple scientific sources exploring the science of transmission conclude that the risk of transmission of Covid-19 is low in outdoor settings (Weed and Foad 9). The outdoors allows for aerosols to be diluted with fresh air and the wind or air flow allows for aerosols to be moved and not linger in one place. However, the weather is shifting around most of the United States, and as case loads continue to rise, there are increased risks when gatherings begin to shift indoors.
In an article made available through the Wiley Public Health Emergency Collection journals, authors Vardoulakis et al. state that “improved ventilation in indoor spaces, including public transport and nursing homes, needs to be considered as a preventative measure because it can substantially reduce the airborne time of respiratory droplets and aerosols.” What is most interesting from their research is that they suggest that despite the current hype of UV air purifiers or ozone-generating air cleaners they are “unlikely to be effective in suppressing airborne transmission since they need relatively long contact times to inactivate viruses.” Vardoulakis et al. do state that air filtration with common domestic devices, “such as portable air cleaners with HEPA filters, can remove small particles of dust or pollen that may act as carriers of SARS-CoV-2.” Although there is no “zero-risk” situation other than complete isolation, practicing astringent hygiene and sanitation measures, wearing a mask, and social distancing can all help to lower the risk of spreading or being infected by Covid-19. Being indoors does increase potential risks and so many factors depend on overall air flow and ventilation, but, an air filtration system or an air scrubber could help to lower those risks.
How to minimize indoor airborne transmission?
Morawska et al., argue that there is significant evidence to “warrant engineering controls targeting airborne transmission as part of an overall strategy to limit infection risk indoors.” In their findings , from the ScienceDirect database, they focus on indoor environments, because this is where most Sars-CoV-2 spread occurs. Not only should ventilation, the process of providing outdoor air to a space or building by natural or mechanical means be considered, but also air cleaning and disinfection devices could be added as part of an overall strategy to help limit possible contraction. Environments where it may be difficult to improve ventilation would offer many advantages to adding a local air cleaning or disinfection devices, especially when holding events or gatherings indoors is required. Morawska et al. also state that the overall effectiveness of portable devices relies on them being appropriately sized for the space, making it crucial that consumers consider the clean air delivery rate (which is the equivalent to the volumetric flow rate) of particle-free air produced by the cleaner.
What's the difference between an air purifier and an air scrubber?
As more consumers become aware of the increased risk of airborne transmission indoors, there is increased demand over which types and how many units will work best. For example, an air purifier is typically a unit that’s primary cleaning method is through the use of a filter. Most common filters for air purifiers tend to be a HEPA (High Efficiency Particulate Air) filters. Ozone or UV filter units would also be considered air purifiers. However, an air scrubber, which is more common in commercial and industrial applications is best at removing fine airborne particles, such as mold spores, dust, pollen, or viral/microbial particles in the air. According to Christopherson et al., air scrubbers work “as air flows through the filter and in between the fibers, airborne particles—such as respiratory and aerosol droplets” are trapped.
At TentCraft, we have been able to help our clients shift their operations to being held outdoors and efficiently support their efforts in supplying drive-thru screening and vaccines tents. However, as we continually search for ways to improve and help our clients, working with PuraFil, a company with a longstanding reputation of being one of the best at supplying solutions that purify air in the world, since 1969, just made sense. Our offerings are focused on quality solutions, which paired nicely with PuraFil’s expertise on creating antimicrobial, multi-stage filtrations systems that remove 99.99% of aerosols carrying viruses. *
Why Choose a PuraShield 500 Air Scrubber?
PuraFil’s PuraShield 500 is a cabinet style unit, similar in size and shape to that of a household dehumidifier that works to quickly and effectively remove many aerosols carrying harmful viruses and bacteria. PuraFil’s PuraWard patented molecular filtration technology (which is one of the key components to this unit being an air scrubber) contains 22 lbs. of filtration media. The HEPA filter (part of a 4-layer filter) removes harmful particulate matter, however, it’s strength, especially with an airborne aerosol virus, is that the filter also works through a method called chem absorption. What is so unique about this unit, perhaps making it one of the absolute best units to add to any given strategy to limit potential exposure (along with social distancing, proper ventilation, mask wearing, astringent hygiene, etc.) is that chem absorption, which happens when air is pushed through the PuraWard filter, is permanent. This means that there is an irreversible reaction that renders viruses, bacteria, mold, fungal spores, etc. unviable. In addition, the PuraShield filter comes in a self-contained canister, which makes changing the filter (which is recommended every 6-12 months depending on how often you are running the unit) not only easy but safe as it does not present additional risks of exposure when removing or cleaning.
TentCraft is proud to collaborate with PuraFil’s technology and offer our clients the option to purchase the PuraShield 500 cabinet with any existing or new order. The PuraShield 500, when added to a 10x15 tent, for example, provides 9 air exchanges within an hour and cleans the air within 7 minutes. The CDC is currently recommending 2-3 air exchanges in an hour, which makes the PuraShield 500 not only a worthy investment but one of the best units available to consumers on the market. These units, when properly used for the total volumetric footprint of the space, present an additional layer of protection, safeguarding your investment, and more importantly, protecting your people.