It’s been proven that COVID can spread in various ways, such as through hand-to-hand touch, by touching something that contains the virus and then rubbing your face, and in other ways, too. A prime transmission route is through contact with virus droplets in the air spread from an infected person speaking, expelling breath or coughing or sneezing.
Last spring, summer and fall, we could partially protect ourselves by socializing outdoors in the fresh air, where it’s more difficult for any COVID-infected droplets to move from one person to another. During warmer weather, opening doors and windows was another precaution Iowans could take to make the spread of the virus less likely.
So this winter, when it’s unlikely we’ll want to live with a cold breeze gusting through open windows, are there steps we can take to put a damper on COVID spread in our home?
Yes, say the experts. And while they caution that taking charge of indoor air quality (IAQ) is only one tool to employ, increasing the flow of air through your home can have a marked impact on viral spread. As a side benefit, better air quality can help those with allergies and can also reduce other noxious pollutants.
There is a caveat: While IAQ solutions can—over time—reduce the virus droplets in your home, COVID safety also requires other standard precautions, including wearing masks, frequent hand washing, using hand sanitizer and maintaining social distance.
The following advice comes from the Environmental Protection Agency (EPA); Scott Bowman, professional engineer and LEED fellow; and The New York Times.
What you can do
Change your furnace filter. If your HVAC system allows it, upgrade to a MERV-13 filter, which catches the virus and particles that the coronavirus attaches to. If your system can’t handle a MERV-13 filter, most systems can handle a MERV-11, which likely filters out about 60% of virus droplets, according to The New York Times.
Run your furnace fan more. Most systems allow you to choose whether to run the fan all the time or only when the HVAC system is either heating or cooling. Running the fan continuously is a plus as systems filter the air only when the fan is running, according to the EPA. Running the fan frequently can also help shift warmed or cooled air equally throughout your home.
Increase the ventilation on your HVAC system. Systems with an energy-efficient air-to-air heat exchanger, heat recovery ventilator (HRV) or energy recovery ventilator (ERV) can make your home safer, per the EPA. This can be added to existing furnace systems too. Creating a positive pressure in a home helps with IAQ and reducing infiltration.
Add air purifiers where possible. Scott Bowman uses air purifiers in his home, with one in his home office and another in the bedroom. Portable purifiers can be used to help clean air in a single room, not an entire home. “Make sure each unit has a HEPA filter, which removes about 99.99% of all air contaminants, including viruses,” he says. His units have several features that do add to the price, including one that has an air ionizer that attracts particles to the filter and another that monitors air quality and ramps up as needed. He advises that you can use an air purifier during a time of higher danger, too, as he deployed one for his daughter who had a contractor working in her home during a remodeling project. He placed it where the work was being done, which helped with COVID and reduced dust and dirt too.
See if UV light makes sense. While ultraviolet (UV) light kills viruses, there are drawbacks as it damages eyes if you look at the light, it’s expensive to install and it’s not an instant fix as UV kills viruses over time as they circulate through your system. Scott says it can be added to any HVAC system as the light does not cause an additional pressure drop. However some experts are wary about UV as an option because they say lights must be carefully engineered during installation so there’s no harm to users. In contrast, Scott believes the UV industry is pretty established and there are all sorts of safeties involved for operations. “A friend found a small unit sized for a small bathroom, and it is always circulating air over the UV light. I got one for my daughter, too, and guess what, it helps with odors, too,” he says.
Raise humidity. Since COVID thrives in dry conditions, using a humidifier system—or even just a simple home humidifier—can keep nasal passages moist enough to slow down viral transmission.
Keep an eye on changes. “As some of these technologies become more mainstream, the technologies should get better and prices should go down,” Scott says. And he notes, there are some interesting developments on the horizon, such as a popular fan company selling a ceiling fan with a UV unit shining up on the ceiling to “sterilize” the room’s air as the fan is circulating it.
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