The best way to deal with any type of virus is to prevent it from getting into your home in the first place. In the lockdowns that we are experiencing at the time of writing this article, it is difficult to keep your home virus free. Adopting habits such as self isolation, wearing a mask, and washing clothes after a trip outside can help, but they are not infallible. We may wash our hands regularly, avoid touching our faces, and follow social distancing protocols, but this only goes so far. Sadly, the most likely place for Covid-19 to reside is in your lungs, and obviously, there is no way to clean your internal organs. Investing in good PPE with an N95 or better mask and using hand sanitizer is essential, but what about the air filtration for your home? In this article, we will look at the efficacy of various types of air filtration systems to deal with Covid-19 and other viruses.
High Efficiency Air (HEPA) Filters
Some of the best HEPA air filters can capture a particle that’s only 2 microns in diameter. These means that they can filter particulates, such as allergens, mold spores, dust particles, and pet dander, out of the air. This drastically improves the indoor air quality (IAQ), but how does is handle Covid-19 and other viruses? The problem is that the majority of viruses are far too small to be trapped by conventional air filters, no matter how efficient they are. The very best HEPA air filters can deal with particulates down to 0.3 microns in diameter with an efficiency rate of 99.97%. But, most viruses are smaller than this, and so they can even pass through the best HEPA filters. Now, you may have heard that HEPA filters are frequently used in hospitals, and this is true. But, it’s important to note that medical facilities do not rely on HEPA filtration, and they use other methods to sanitize the air. Some larger viruses can be captured by the best HEPA filters, but generally speaking, they will not offer much protection against Covid-19.
Electronic Air Filters
An electronic air cleaner traps particulate that are traveling within your air. A prefilter deals with most of the particle, and any that get past are directed into a second filter that’s charged with electricity. The electronic air filter has a pair of oppositely charged plates that charge the contaminants. Some electronic air filters also have a further process that generates ozone, these oxygen molecules are then attached to the contaminants such as bacteria, viruses, and molds spores, and this kills them.
The Journal of Natural Science, Biology, and Medicine have stated that ozone generating filters can kill coronaviruses. This method has proven to be effective against SARS, which shares many characteristics with Covid-19. Ozone filtration can destroy up to 99% of may virus cells if the exposure time is sufficient. Although ozone has not been extensively tested on Covid-19 at this time, we have no idea about the true efficacy of this method.
The EPA has stated that there is data to support the theory that low levels of ozone can reduced concentrations and inhibit the growth of certain organisms. But, there is a caveat, the ozone concentrations must be 5-10 times higher than recommended by current public health standards to fully decontaminate air. So, low levels of ozone created in an electronic air filter can reduce the threat of viruses (including Covid-19), but they may not eliminate it entirely.
Ultraviolet (UV) Lights
UV lights bathe an area with a spectrum of light that can kill bacteria and viruses, including SARS and MERS. But, it takes time for UV light to work, the light damages the DNA of the virus and then prevents it from replicating. Many UV lights are located in a stationary position somewhere along the incoming stream of air. But, just like the sun, the UV rays can be harmful to the skin after contact, and they must be treated with respect. UV light his highly effective at killing viruses, bacteria, and mold on a surface such as an evaporator coil. But, imagine Covid-19 traveling through a duct system at around 450 cubic feet per minute. At this typical speed, the UV lights would not have sufficient time to kill a coronavirus as it passed through the ductwork.
UV light has not been proven to kill Covid-19, but it does work on other coronaviruses such as MERS and SARS. So, although we don’t have definitive confirmation at the time of writing this article, it is likely that UV light would work on Covid-19. The main problem is the UV light exposure time that is required to kill the virus. So, it’s not likely that UV lights are the best option to remove Covid-19 from the duct system as air enters your home.
There are many types of air scrubbers on the market; these air purification systems sanitize the air by drawing oxygen and water molecules present in the air into the unit. The air is then passed through a matrix where the molecules are transformed into oxidizers that are then introduced back into the air stream and into the home. The oxidizers attach themselves to airborne and surface contaminants in your home. These oxidizers can kill many contaminants, such as E.coli, strep, staph, swine flu, avian flu, and they can even eliminate volatile organic compounds (VOCs).
Air scrubbers have not been tested on Covid-19 at the time of writing this article. But, this system has a number of advantages over others found on our list. This air purification method is extremely effective at killing bacteria, viruses, and mold, and this occurs very quickly when compared to UV light. It’s worth mentioning that certain air scrubbing systems include a UV light source for extra protection.
No consumer grade air quality products have been extensively tested with Covid-19. Most of the air filtration methods on our list are effective against coronaviruses with various degrees of efficacy. But, in certain applications, they may be less effective due to the exposure time required and other factors. IAQ is very important for health generally, and it makes good sense to clean the air that is circulating throughout your home. If you want to learn more about eliminating viruses, bacteria, and mold to improve your IAQ, contact a local HVAC specialist for expert advice today.