How does a busy shopper find the right size air purifier for a room they want to clean? The U.S. Centers for Disease Control recommends aiming for five air changes per hour, a metric known as ACH. When looking at an air purifier, pay attention to the airflow in cubic feet per minute at the lowest setting. When measuring the cubic meter area of your room, you need the area of the room multiplied by the height. Imagine a 30cm Styrofoam cube. How many cubes fit in a room?
Anyone buying an air purifier also has to look for two acronyms and terms. First, look for CARB certification, which means the air purifier meets the strict standards of the California Air Resources Board. Next, check the filter type. Below we explain the differences. Also, don’t forget to unpack your filter! It’s a real horror when you realize that you’ve been using your air purifier with a HEPA filter wrapped in plastic.
HEPA filter: This is a highly efficient particulate air filter that can remove at least 99.97 percent of dust, mold, pollen, bacteria and airborne particles up to 0.3 microns in size. It’s a great option for people who suffer from allergies or breathing problems because it can help remove airborne particles that can trigger symptoms like sneezing, sore throat, difficulty breathing, coughing, and more. However, it is worth noting that HEPA filters do not remove volatile organic compounds from the air like activated carbon filters. However, these are typically combined with carbon filters.
Activated carbon: Activated carbon filters (also called activated carbon) are highly effective because they are very porous and have a large surface area, which allows the filters to absorb gas pollutants, odors and VOCs. They are best for removing fumes, smoke and chemicals from the air. However, these filters may need to be replaced more frequently depending on the environment. For example, if a forest fire breaks out in your area and the air purifier is working more intensively than usual, it is important to replace a saturated filter to prevent toxic gases from being released back into the air.
Washable air filters: Some of the air purifiers listed in this guide come with washable pre-filters in addition to a HEPA and/or carbon filter – which is what you’ll typically find. These are the most cost-effective because you don’t have to buy new filters every time you need to replace a filter. Simply remove it, scrub it with soap and water and let it dry.
UV-C disinfection filter: Ultraviolet filters use UV light to kill viruses, parasites, mold spores and bacteria. They cannot remove airborne particles, VOCs or gas pollutants and are therefore only fully effective when combined with a HEPA filter. According to the U.S. Environmental Protection Agency, UV light without proper lamp coating has the potential to emit ozone. We recommend checking this list from the Association of Home Appliance Manufacturers for air purifiers proven to emit little to no ozone.