The following article from the Journal of Occupational and Environmental Hygiene makes a compelling case for adding HEPA filtration to indoor environments in order to greatly reduce the chance of Covid spread.
The article has a couple of important points.
Based on their model, an office worker has a 40% chance of contracting Covid when sharing an office with an infected worker “Even with use of N95 masks in this scenario” after 1 week of exposure !
By combining HEPA filtration (12 Air Change per Hour – 12 ACH), the probability of contracting Covid from the office environment over a 6 month period drops to 0.003%.
Conclusion: Use HEPA filtration in indoor environments in this time of panemic, and continue to use to avoid other airborne pathogens.
Arising out of our personal and professional need for high quality portable air filtration during the COVID-19 pandemic, the inspiration and launch of the the newest member of the Airscape family was born.
We noticed an absence of cost effective and high quality portable indoor air filtration products utilizing critical core attributes:
*high number of air exchanges
*quality filtration media: MERV pre-filter and HEPA filtration
*particulate level filtration appropriate for airborne size micro-droplets (i.e. COVID-19, influenza etc.
*quiet operation (suitable for conference rooms during meetings)
*efficient energy utilization (speed controllable, low energy use ECM motor)
We utilize this product in our headquarters and trust it to keep our team safe.
Our CFB HEPA Filters are currently being used by a number of hospitals to create negative pressure isolation rooms for COVID-19 patients. They are typically paired with an inline fan to exhaust the contaminated air from those areas, filter and then discharge it safely outside. Discharging the air without any filtration is considered risky since you are spreading/distributing the virus particles extracted from the patient areas. If you have questions on how to build negative pressure isolation rooms give us a call.
What is a HEPA?
HEPA stands for high-efficiency particulate arrestance. To be classified as a HEPA, the air filter must remove at least 99.97% of particles whose diameter is equal to 0.3 μm. Classification at 0.3 μm is important because this is the weakest point in the filter’s performance – typical HEPA filtration efficiency increases for particle diameters both less than and greater than 0.3 μm.
Image courtesy of the National Institute for Occupational Safety and Health (NIOSH)
Virus particles, due to their small size, typically fall in the diffusion regime of HEPA collection efficiency. Specifically, the virus that causes COVID-19 is approximately 0.125 μm in diameter. That diameter is perfectly within the particle-size range that HEPA filters capture with great efficiency: 0.01 μm and bigger (see the NIOSH diagram above).
Want to ready more about HEPA and how they filter particles the size of viruses? We found the Submicron and Nanoparticulate Matter Removal by HEPA-Rated Media Filters by NASA study is a great source of reliable technical info. Page 7 of the paper has an excellent illustration of filter efficiency as a function of particle diameter for sizes 0.01 μm and above.
A few weeks ago our sister company AirScape Fans (airscapefans.com) was ramping up whole house fan production for the summer season. Now they are very busy making HEPA filtration units for hospitals, and yes, observing Covid safety protocols. Masks [check], distancing [check], good ventilation [check], doors open for extra air dilution [check], hand sanitizer [check], outdoor breaks in the sun [check]. They (as did we!) spent a lot of time writing procedures on how to stay safe.
