Air purifiers are used in many different environments to help people breathe easier. They are typically used for and evaluated by their ability to remove harmful particles, such as allergens, from the air. With so many different filters and varying technologies, we are left wondering if and how air purifiers help with smells.

What Even Is a Smell?

In order to understand more about what air purifiers are capable of, we first need to break down what odors actually are! According to an article from the American Chemical Society, what we experience as an odor is actually a set of molecules in the air that travel into the nose. Via specialized receptors in our nose, electrical signals are sent to the brain that allow us to experience thousands of familiar odors—from fresh-baked cookies to stinky fish.

Common sources of household odors are:

• Food/cooking
• Pet odors
• Cleaning products
• Laundry
• Garbage disposals
• Trash
• Body odors
• Restrooms

Are Odors Normal?

It is common for indoor environments such as homes to have some sort of odor. The type of odor or smell is unique to the habits and cleanliness level kept in the home. Not all smells are worthy of investigation; however, there are some bad smells that need immediate attention if you notice them in your space.

These odors are usually on the foul, sour, or sulfurous side of the spectrum. One such odor is the smell of rotten eggs. When living in a home with gas appliances or heating, a foul-smelling odor is a warning sign. In this case, calling a local utility to check for leaks is advised as a chemical is added to utility gas to help with leak detection.

How Do VOCs Relate to Odor?

Odors themselves are not typically carrying the organisms that cause illness. In fact, bacteria are many times larger than an odor. Bacteria and organic compounds, such as VOCs, cause irritation and illness. Volatile Organic Compounds (VOCs) are defined by the EPA as gases from specific solids and liquids that contain carbon molecules.

Outdoors, the EPA regulates levels of VOCs for the protection of the environment, health, and the ozone layer. However, indoors, a chemical may not be considered a VOC because it is not regulated outdoors by the EPA. At this time, there are no enforceable guidelines from the federal government regarding the use of and exposure to VOCs indoors. It is important to know what chemicals are in use in the home and it is recommended to increase ventilation when using any of the listed sources of VOCs. Always follow the directions when using a chemical in the home, especially those known to be sources of VOCs.

Common sources of VOC include:

• Solvents
• Wood treatment chemicals
• Aerosols
• Cleaners and disinfectants
• Air fresheners
• Pesticides
• Dry cleaning
• Construction materials
• Glues

VOCs are known to cause irritation and discomfort—ranging from mild symptoms to more severe reactions—in the nose, eyes, throat, and skin. The EPA states that VOC concentrations are (at minimum) doubled in concentration inside homes when compared to outdoor air. Interestingly enough, the EPA also states that there is virtually no difference in the indoor concentration of VOCs even if you live in a remote area.

Some VOCs are worse than others. According to the Berkeley Lab’s Indoor Air Quality Findings Research Bank, some VOCs are known to cause cancer in animals at high concentrations. Formaldehyde and benzene are two VOCs that are considered by some regulatory authorities as probable carcinogens. The exact risk factors are difficult to determine with concrete data based on varying environmental uncertainties.

Knowing what smells or odors are connected to specific VOCs and their effects is a topic requiring further research. However, even low levels of continued exposure to VOCs are known to be harmful to health.

How Do Most Air Purification Systems Capture Pollutants?

The simplest form of an air purifier is essentially a fan with a high-performing HEPA air filter that captures airborne particles such as smoke, dust, mold, pollen, and bacteria. As air is circulated continuously, the number of particles in the air is reduced with each exchange. Air purifiers with this basic operating system will vary based on their ability to exchange the air in your home. This naturally leads us to define a term commonly used when researching air purifiers - CADR.

What Is CADR?

The Association of Home Appliance Manufacturers defines CADR as Clean Air Delivery Rate. This means that a device is rated for a specific reduction of solid particulate over a period of time, and this measurement is dependent on the size of the room. In testing, CADR is measured in a uniform-sized chamber with known particulates, but real-life CADRs vary significantly. The maximum CADR possible is a value of 450 CADR for pollen and smoke and 400 CADR for dust.

As CADR is directly related to room size (sq ft), air purifiers must be selected based on a room’s square footage to be effective. Efficient large surface area filters effectively trap and continuously exchange air as a large surface area allows more particles to flow through the filter media with lower air resistance. The lower resistance means that more air passes through the fibers with less effort from the motor—aiding in energy efficiency. As this cycle repeats, the amount of space that allows a particle to freely exit the filter decreases, cleaning the air more and more. CADR rates are an effective measure of how well an air purifier will remove particulates at full capacity, therefore air flow is critical to CADR. However, CADRs do not measure an air purifier's ability to reduce gases, odors, or microbial contaminants. To target odor, you also might want to look for activated carbon filters.

What Are Activated Carbon Air Filters?

One popular odor reduction technology involves the use of activated carbon filters. It is common to use activated charcoal filters as part of an air cleaning process. As a bonus, these filters also help remove VOCs from the air by molecular diffusion! Essentially, harmful pollutants (gases) are pulled through the activated carbon until their components are trapped in the layers of the activated carbon filter itself. This process is how foul odors such as cigarette smoke are filtered down and trapped. Pet odors are also reduced when an appropriately sized air purifier with activated carbon is used.

Final Thoughts

Air purifiers, when selected properly, are able to reduce odors in the home and even remove some VOCs that are harmful to health. Investing in clean air is a worthy investment in health that reduces asthma symptoms, allergies, and more, and leads to greater overall comfort.

Finding an appropriate air purifier is worth the effort. This information on air purification technology helps you select the proper device to meet your needs. For more help, talk with an Air Purification Expert here on Curated.