Humidity levels and temperatures that are too high can cause bacteria and mold growth in particulate filter media, such as HEPA. If the filter is not properly maintained, it can even introduce more contaminants into the home, which is the last thing anyone wants. By using HEPA filters in both vacuum cleaners and air purifiers, people can reduce the amount of allergens and airborne pollutants in their home. Manufacturers of high-quality HEPA filters voluntarily test and certify their filters to meet DOE standards, labeling them as “absolute HEPA” or “true HEPA”.Unfortunately, allergens can enter the home through open doors and windows, so even if a single drafty window allows millions of particles to enter the air, using a HEPA filter cannot guarantee the removal of all allergens.
The two studies included in the systematic review only focused on the use of air filters on bacteria in the air, not on viruses. Randomized controlled trials are needed to demonstrate the effects of portable HEPA air filters on the incidence of respiratory infections, including those caused by SARS-CoV-2.HEPA filters trap most of the particles in the air, so they tend to clog more quickly than traditional filters. No studies have been found that investigated the effects of air filters on the incidence of respiratory infections. Additionally, no studies have been found that investigated the effects of commercially available portable air filters on the incidence of respiratory infections in the community. Carbon filters fill by weight, so if there are more contaminants in your environment, you'll need to change the filter more often.
To keep your family safe on an ongoing basis, it's important to keep control of your household HEPA filter. It's also important to note that for many home HVAC systems, investing in a HEPA filter is not limited to just purchasing and installing it. If someone in your household suffers from allergies or asthma, investing in a household HEPA filter will help reduce and eliminate airborne particles that cause or may worsen symptoms. According to the EPA Home Air Purifier Guide, using HEPA air filters in portable air purifiers and HVAC systems can help reduce allergy and asthma symptoms. I would recommend that authors expand their research criteria (such as including a centralized HVAC system with air filter studies, etc.).
MERV-13 air filters are generally the best filter upgrade for residential use for typical HVAC systems. The experimentally contaminated air was filtered using a portable device that combined HEPA filtration and UV light.