When used correctly, air and HVAC filters can help reduce airborne contaminants, including viruses, in a small building or space. Cleaning or filtering the air alone is not enough to protect people from COVID-19.What you need to know to keep you and your building safe Can building air filtration protect me from contracting COVID-19? What filter should I use to protect people in my building from COVID-19? Why shouldn't you use the most efficient filter you can find? I know hospitals have good filtration, why don't we all use systems like these? What about ultraviolet (UV) lamps? Do they work? What about portable air filters Doesn't filtration require droplets that cause COVID-19 to be in the air? I've heard that these are large droplets, what precautions should I take when changing filters? What about ionizers, ozone generators, plasma and other air cleaning technologies? Where can I go for more information? As we all socially distance and stay at home amid the COVID-19 pandemic, some may wonder what else they can do to “flatten the curve”. While hand washing and staying at home remain the most effective means of limiting the spread of the virus, conflicting information is emerging about the role and effectiveness of air filters. Can building air filtration protect me from contracting COVID-19? Leakage in building heating, ventilation and air conditioning (HVAC) systems may be part of a general risk mitigation approach, but it is generally not considered a solution on its own.
There is no direct scientific evidence of benefit, but reduced exposure can reasonably be inferred based on the ability of some filters to remove particles containing a SARS-CoV-2 virus. For filters to have any impact on the transmission of infectious diseases, transmission must occur through the air route, filters must be properly installed and maintained in systems suitable for treating recirculated air, and filters must be designed appropriately for the building in which they are used. More importantly, in most buildings and in most situations, filters can be significantly less effective than other infection control measures, such as social distancing, isolation of known cases, and hand washing. What filter should I use to protect people in my building from COVID-19? Hospitals (and many health centers) have specially designed mechanical systems that can adapt to the levels of filtration they need.
They are often based on other control systems and strategies (e.g. Most importantly, they have dedicated staff who operate and maintain this equipment to provide maximum benefit. What about ultraviolet (UV) lamps, do they work? What about ionizers, ozone generators, plasma and other air cleaning technologies? None of these technologies have been shown to reduce infection in real buildings, even if they are promising based on tests conducted in a laboratory or in an idealized environment. Some of them have substantial concerns about secondary issues (such as ozone production).
What About Portable Air Cleaners Yes, most public health guidelines suggest that transmission of COVID-19 is predominantly associated with large droplets. This is why air filtration is only a small part of a solution, since it generally does not address transmission by contact with the surface or by close contact between people. However, the distinction between droplets and in the air is the size of the particles. We know that (a) droplets can remain in the air for long periods of time (for example,.
In addition, DNA and RNA from other viruses, which are generally associated with droplets, have been found in the filters used. What precautions should I take when changing filters? In general, it is prudent to assume that filters have microbiological active material on them. It is not known if this represents a significant risk of infectious disease from viruses, but the precautionary principle would suggest that care should be taken. This becomes particularly important in any building (including a home) where there are known or probable cases of an infectious disease, including COVID-19, and it also extends to portable air purifier filters and vehicle cabin air filters.
Filters should be replaced with the system turned off, with gloves, with respiratory protection if available, outdoors if possible and discarded in a sealed bag. Where can I go for more information?. Scientific advances in filter design and manufacture have reduced the amount of increased pressure drop and its resulting impact on HVAC operations, but not all filters have adopted the newest technology. Use protection when changing the filter, as particles inside the filter may contain live viruses.