Do Air Purifiers Work?

How Do Air Purifiers Work?

With the increased interest in indoor air quality, many people are asking the question, “How does an air purifier work?” In general terms, air purifiers can be as simple as a mechanical filter which uses some sort of mesh material to physically trap particles. More sophisticated types apply an electronic charge to airborne particles, so they are attracted to an oppositely charged media. Adsorbent filters are effective at mitigating odors, and UV purifiers use ultraviolet light to kill bacteria and mold growing on your HVAC’s indoor cooling coil. So, how do air purifiers work? Let’s take a closer look at the five main types:

• Mechanical Filters: Mechanical air filters are typically made of a mesh material designed to capture or trap airborne particles as they pass through the material. Mechanical filters can be basic 1-inch furnace filters that can attract dust, pet dander and other larger particles. Higher efficiency pleated filters of various thicknesses (4-inch pleated filters are common) can provide more effective filtration due to having a larger surface area. The most effective mechanical filter is the HEPA (high efficiency particulate air) filter which must be certified to trap 99.97% of particles sized 0.3 microns in diameter. Mechanical filters offer a wide variety of effectiveness, and must be replaced per the manufacturer’s recommendations, often every 1-3 months. Leaving a mechanical filter in place too long can cause your HVAC system to lose efficiency.
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• Electrostatic Precipitators (ESPs): These electronic air cleaners use an electrostatic process to charge airborne particles, which are then attracted to oppositely charged surfaces such as collector plates or other media. As the collector plates or media become more particle laden, they start losing efficiency – so proper cleaning of collector plates or replacement of filter media will be the key to maintaining efficient filtering.
• Ionic air purifiers: Sometimes referred to as a negative ion air purifier, these air purifiers place a charge on airborne particles so that they are attracted to surfaces such as floors, tables, walls, and even the room’s occupants. Some ionic systems are set up to also collect the charged particles back into the unit. These systems can be effective at removing smaller airborne particles such as those found in smoke, however they may be less effective at removing larger particles like dust or pollen.²
• Adsorbent filters: Adsorbent filters are similar to mechanical filters in that they collect airborne particles as air passes through the adsorbent material. Adsorption is a process by which selected materials, such as volatile organic compounds, are attracted to the surface of the adsorbent material, often activated carbon. Activated carbon filters are best suited to controlling odors from VOCs commonly found in home construction and renovation. Keep in mind that not all odors are attracted to adsorbent filters.
• UV purifiers: UV purifiers use ultraviolet lamps to kill microorganisms such as fungal spores, bacteria and viruses. In residential use, UV purifiers are typically used to treat interior surfaces of HVAC systems – specifically the indoor coil used in central air conditioning or heat pump systems – where organic matter tends to accumulate. UV lamps need to be replaced annually as they become less effective over time.

Air Purifier Criticism

In the world of air purification, be aware that not all technologies are alike, and consumers should be wary of claims that seem to be too good to be true. Before purchasing any air purifier, be sure you are purchasing from a trustworthy source and using filtering systems or technology that have been tested and proven to be effective. For example, to be called “HEPA”, filters must be certified to be 99.97% effective at trapping particles sized 0.3 microns. These filters can be very effective when used as recommended.

As you consider your options for air purification in your home, understanding the types of air purifiers as described in the previous section is a great way to start the decision-making process. It will also help to understand industry terminology used to compare filtering capabilities, such as MERV or CADR. MERV is an acronym for Minimum Efficiency Reporting Value – the higher the MERV rating, the better the filter – with 16 MERV being roughly equivalent to HEPA filtration. Carrier filters are rated up to 15 MERV, and our Infinity^® air purifier not only filters the air, it inactivates 99% of select airborne germs and viruses trapped in the MERV 15 filter, including coronavirus, human influenza, the common cold and bacteria that causes strep throat.³. CADR, or Clean Air Delivery Rate, indicates an air cleaner’s capabilities in terms of the volume of filtered air it delivers. The higher the number, the faster it works. Also, CADR has separate scores for tobacco smoke, pollen and dust.

To learn more about Carrier portable air purifiers and filter check out our Carrier products for your home.

Do Air Purifiers Really Work?

We hope we’ve answered the question of do air purifiers really work! While there are a number of high-quality options available, remember to keep your expectations realistic. No air purifier can remove 100 percent of airborne contaminants, but there are a number of reliable options for mitigating many of the contaminants in the home, including some odors. Remember that selecting the right air purifier for your home involves understanding the types of pollutants you likely have inside. Stick to the tested and proven solutions like HEPA (or other high-efficiency media) filters and ESPs for particle collection, and adsorbent media like activated carbon for odor control.

The Carrier Infinity air purifier offers exceptional filtration along with its patented Captures & Kills^® technology to inactivate select airborne pathogens. This option provides whole-home purification. For a portable option that can provide effective, three-step filtration for both airborne particles and odors, our standard and smart room air purifiers are also worth a closer look.

Disclaimers:

¹ https://www.epa.gov/report-environment/indoor-air-quality
² https://www.epa.gov/indoor-air-quality-iaq/what-are-ionizers-and-other-ozone-generating-air-cleaners
³ The Infinity air purifier has demonstrated effectiveness against the murine coronavirus, based on third-party testing (2020) showing a >99% inactivation, which is a virus similar to the human novel coronavirus (SARS-CoV-2) that causes COVID-19. Therefore, the Infinity air purifier can be expected to be effective against SARS-CoV-2 when used in accordance with its directions for use. Third-party testing (2012, 2007) also shows =99% inactivation for the type of virus that causes common colds, Streptococcus pyogenes and human influenza. Airborne particles must flow through your HVAC system and be trapped by the MERV 15 Infinity filter to be inactivated at 99%. The Infinity air purifier achieves a MERV 15 rating based on third-party testing (2012) showing 95% of particles size 1.0 to 3.0 microns captured and 85% of particles size 0.3 to 1.0 microns captured. Learn how it works.