How Do Air Purifiers Work?

With more people working or “going to school” at home, there has been a rise in popularity of healthier indoor environments. As a result, many people are asking themselves, “How do air purifiers work?” It's a great question, and with the growing number of air purifiers on the market, the answer may vary from product to product.

In this post, we will break down the different types of air purifiers available and how they work to help provide cleaner, healthier indoor air. We will also expand on how to purify the air in your home, and in doing so will help determine the best way to purify air in a home. And for those who already use an air purifier, we will explain how to know if your air purifier is working and how to maximize the benefits of using it.

How air purifiers work: Most air purifiers operate in a similar manner. A fan draws air into the unit, airborne pollutants are trapped in a filter or filters of some kind, and cleaner air is returned back into your living space. The biggest differences between air purifiers are the type and quality of filtration, the strength of the air circulating fan, and any additional features that may be built in, such as air quality monitoring or Wi-Fi® connectivity. To help you compare the capabilities of air purifier units, look to see if the manufacturer publishes the CADR (Clean Air Delivery Rate). The higher the CADR number, the more particles the unit can filter and the larger the area it can.

Filtration technology: Air purifiers typically rely on either mechanical or electronic filtration for the removal of airborne particles such as dust, dirt, mold spores and pollen. Mechanical filters can be quite effective, especially HEPA (High Efficiency Particulate Air) filters that can trap 99.97% of airborne particles as small as 0.3 microns in diameter. Electronic filters such as electrostatic precipitators (ESPs) also offer highly productive filtering capabilities. For odor removal, adsorbent media filters such as activated carbon filters combine mechanical filtration and a chemical process. Finally, to kill or inactivate microorganisms such as bacteria, viruses and fungal spores, ultraviolet germicidal irradiation (UVGI) may be used as well.

Additional features: Air purifiers may also include multi-speed fans with automatic or selectable speed settings, air quality monitoring, replace filter indicators, LED displays, and “smart” operation accessible via Wi-Fi with a connective device.

Most air purifiers combine more than one of the above technologies to “purify” the air. For example, Carrier air purifiers use a three-layered approach. The first two layers are mechanical filters – a pre-filter that captures larger particles like dust, dirt or pet dander and a second, more advanced, high-efficiency filter that traps better than 99% of airborne particles as small as 0.3 microns. The third layer is an activated carbon filter that helps remove odors. Carrier air purifiers continuously monitor air quality and can automatically alter fan speeds to achieve your targeted results.

How to Purify the Air in Your Home

Purchasing a high-quality purifier from a reputable manufacturer can be a great start towards answering the question of how to purify the air in your home. However, even the best, most efficient air purifier can use a little help in reducing indoor air pollution. Removing sources of air pollution is one of the most effective techniques you can put in place. Limiting or eliminating tobacco smoke, reduced usage of toxic cleaning products, removing clutter such as throw pillows or stuffed animals, or even replacing carpet with a hard flooring are good examples. During the warmer months, consider spending more time cooking outside on a grill to reduce potential sources of odors or smoke from meal preparation. Increasing ventilation helps as well – anything from running your furnace fan more frequently, adding a whole-home ventilator for controlled intake of outdoor air or something as simple as having open windows when the weather allows it. Keep in mind that when introducing outdoor air to your home, you may be introducing additional pollutants, depending upon the outdoor air quality in your area.

Other ways you can help improve your indoor air quality include:

• Regular dusting and vacuuming can help reduce build-up of dust and pollen. Because both activities can also stir up dust particles, consider wearing a mask or using a HEPA or certified asthma and allergy friendly vacuum.
• Consider steam cleaning carpets – the heat can actually kill dust mites.
• Turn on exhaust fans in your kitchen and laundry room when appliances are running, especially if you have a gas stove
• Limit the use of candles which can add soot and volatile organic compounds into the air.
• Be sure that any gas, wood, oil, kerosene or coal-burning appliances are properly vented and used in accordance with all operating instructions to reduce the introduction of nitrogen dioxide (NO2).
• Controlling humidity – some microorganism thrive in humid environments. Maintaining relative humidity levels below 60%, and ideally between 30% - 50% can help improve indoor air quality.
• While less effective than a mechanical air purifier, certain plants can act as natural air purifiers while adding a touch of nature to your home.

Best Way To Purify Air in a Home

The best way to purify air in home locations is to use an air purifier that is properly sized and rated for filtering airborne pollutants. Air purification products by Carrier can be an effective option for most homes and homeowners. As you research the air purifiers available, we recommend getting up to speed on standard ratings and terminology that can help you make an informed decision. Here are some items to consider when shopping for an air purifier for you home:

• CADR – This is an acronym for Clean Air Delivery Rate and is a standardized rating for how quickly an air purifier can remove pollutants from an area. The higher the rating the better. An air purifier can have different CADR ratings for smoke, pollen and dust. However, not all manufacturers publish CADR ratings.
• Size of the model/size of room – Most manufacturers will identify a maximum room size for which the air purifier is ideally suited. Be sure you are purchasing a unit that is adequately sized to purify the air in the space you intend to use it. Keep in mind that not only will you need to measure the square footage of the room, ceiling height will need to factored in as well.
• HEPA – This is an acronym for High Efficiency Particulate Air. True HEPA filters can trap 99.97% of airborne particles as small as 0.3 microns in diameter, and are considered the gold standard of mechanical air filtration. Some manufacturers will market “near HEPA” capable filters, which usually means they simply have not received certification of performance. These can still be considered quite effective at trapping airborne particulate matter.
• MERV – This is an acronym for Minimum Efficiency Reporting Value. The MERV value assigned to a mechanical filter indicates its ability or efficiency at removing airborne particles of a certain size. The higher the number, the more particles and smaller diameter particles a filter can contain.

As a part of your search, we recommend taking a closer look at air purification products by Carrier. Carrier air purifiers combine a three-step mechanical filtration process with an 18-speed fan to provide versatile and efficient removal of airborne particulate matter down to 0.3 microns. A built-in air quality monitor rates the quality of the air in your space, allowing you to manually adjust fan speeds for more or less filtration as needed. It can also be set to automatically adjust fan speeds as conditions change, and a Wi-Fi® connected model can be operated from an internet-connected device.

For those you who already own one, you may be asking yourself, “how do I know my air purifier is working?” Unlike surface mold and mildew which can be seen easily, airborne pollutants are largely unseen by the naked eye. As a result, you’ll need to resort to a little more investigation to determine how well your air purifier unit works in your home.

• Start by checking the manufacturer’s specifications for the model you own. Is it properly sized for the room? If not, consider moving the purifier to a space that better matches the unit’s capabilities.
• Be sure the unit is placed properly – typically, this means in a location that allows for unimpeded airflow into and out of the unit, and not in a corner. Also, because they are portable, consider moving the air purifier to the space you are occupying as long as it still meets room sizing requirements. And, if possible, place it near a source of airborne pollutants.
• Inspect and check the filter media regularly. If you can see a visible buildup of dust, dirt or the like, it is doing its job. In the same vein, be sure you are following the manufacturer’s recommendation for filter replacement or other maintenance. Carrier air purifiers make this easier with an LED screen that lets you know when it’s time to change the filter.
• Check to be sure the unit is working properly. For example, is the fan creating airflow into and out of the unit, or is the unit making unusual noises? If the unit does not seem to be operating properly and you cannot resolve the issue yourself, contact the manufacturer.
• Is it running? The more you operate your air purifier, the more time it spends cleaning the air, and the more airborne particles it can remove.

If you need to replace your current model or simply want to supplement your current purifier with a new one, Carrier offers an air quality quiz on its website. To take the quiz, go to our Carrier at home consumer website and look for the “take the quiz” link under the headline “healthier air starts with knowing what’s in it.”