You would be hard-pressed to find a house without its own unique smell, but many of these smells are undesirable and even embarrassing. Some of these smells are distinct—especially pungent cooking smells, pet dander and musty mold smells. Can an air purifier remove these odors? If so, which ones are most effective? You will have to dig a bit further to determine how an air purifier can help with lingering smells and odors in your home.



What makes up common odors?

Human beings are capable of habituation, a fancy way of saying your sensitivity and ability to discriminate odors diminishes over time with exposure. The brain tends to ignore those smells that you are constantly immersed in, focusing instead on scents and odors that are different than your accustomed environment. That is why you may not notice the animal smell of your beloved pets but absolutely notice the smell of rotting food.

The common odors that make up our day-to-day life are actually airborne chemicals, and many of the scents arise from volatile organic compounds (VOCs). Some VOCs, such as formaldehyde, may cause a range of adverse health effects. However, many dangerous substances are odorless, meaning the smells that prickle your nose might be far less dangerous.

What are these bad smells, exactly?

The human nose can detect and distinguish thousands of scents, even if exposed to extremely small amounts of airborne chemicals. But what are these chemicals?

For example, when you smell roses, lavender or geraniums, you are getting a big whiff of their natural chemical mixtures of VOCs. If you were to smell each one blindfolded, it might be hard to tell the difference because all three contain large proportions of geranyl acetate, a natural organic compound commonly used in the production of perfumes, soaps and candles.

When you peel a banana, your nose is bombarded by isoamyl acetate, the organic compound giving bananas and pears that signature fruity smell and taste. Called “aroma compounds,” all the world’s scents and flavors come from chemical compounds hitting our olfactory receptors. There are many classifications within aroma compounds, to an extent dizzying even to chemists.

Where do unpleasant odors come from?

Every family has different habits when it comes to hygiene and domestic cleanliness, but the bad odors that you cannot seem to eradicate are not simply happenstance. They are the result of chemical compounds in the air, whose volatility makes them noticeable to your olfactory senses. These nasty smells are not only a nuisance but represent tangible air pollution capable of causing adverse health effects, according to the CDC.

An air purifier may be the solution to some of these unwanted scents, by removing particles that cause odor from the circulation of indoor air.

However, some air purifiers are more potent than others in getting rid of lingering smells. Here is a look at all the options currently available to consumers, as well as an exploration of where unpleasant odors may come from in your home.

Most smells, pleasant or otherwise, are the result of receptors in your nose detecting a chemical in the air, a job your nose does extraordinarily well—even if you wish it did not. Airborne chemicals are generally much, much smaller than many others found in your home, making filtering them from the air a challenge for most air purifiers.

Pet odor

Pet dander, or tiny flakes of skin, is a common source of sometimes unpleasant odors in our homes. A national pet owners survey in 2017 found that 85 million US households own a pet – that means a pet can be found in nearly 65% of US households.

Your pet’s skin secretes tiny proteins, oils, and other substances, and all animals with fur or feathers will shed dander. It can create an odor in your home and also pose a legitimate threat to those with allergies.

The awful mustiness of mold and mildew

Preventing mold and mildew from forming is always the best option. But if you smell that horrible musty smell in your home, do not panic. There are numerous ways to remove fungi like mold and mildew, which should be done quickly after discovery to avoid health risks.

Household fungi can have similar smells but are treated differently, so their identification is important. Their musty smell comes from VOCs they emit during various stages of growth and while their spores may be toxic and pose risks themselves, their smell serves as a useful indicator that your home has a problem.

Smoke

Made up of particulate matter and gaseous pollutants, smoke is both an odorous nuisance and extremely dangerous to inhale. Because smoke cannot be entirely filtered out of the air by conventional air filters alone, taking the necessary steps to protect your home from smoke is critical. Additionally, it is important to remember that while some air purification technology can remove smoke from the air, it should not substitute direct measures to stop smoke at its source.

Cooking odors

Unfortunately, the delicious meal you may have cooked up may end up lingering in your kitchen and home long past its welcome. The smells you associate with pungent food are aromatic compounds, tiny airborne chemicals to which our noses are notoriously sensitive.

Bacon, for example, smells strikingly specific when frying in a pan. As it sizzles, it releases volatile organic compounds and hydrocarbons like the pyroligneous acids found in hickory wood, all of which are too small and difficult for traditional HEPA filters to remove from the air.

General odors in the home or office

An unpleasant combination of odors in a home or office could lead you to consider popular fragranced products like air fresheners. However, in an attempt to remove annoying and potentially embarrassing strong smells, adding fragrances into the air to mask the problem could introduce additional VOCs, which can increase your risk factor for a number of health problems.

Nobody likes a stinky home or workplace, but the latest science shows that living, working, or shopping around pronounced smells has a demonstrable effect on human health and decision-making. In study of over 1,000 American adults, 34.7% reported health problems when exposed to fragranced products in the workplace. 20% stated they would leave a business as quickly as possible if they smelled air fresheners or fragranced products, and 50% prefer that hotels, health care facilities, business professionals and airplanes were fragrance-free.

Why odors are so difficult to filter from the air

Odors are difficult to filter from the air because traditional air purifiers (such as HEPA) simply are not designed to remove gases like VOCs from the air. Instead, most air purifiers are designed to filter larger particles such as dust, dander and pollen. Traditional air filters, referred to as mechanical filtration, serve to collect these particles on a filter surface, and do not remove gaseous elements such as VOCs. However, as you will see below, carbon filtration is one type that can remove VOCs, though it does have its drawbacks.

Air purifiers’ effectiveness in controlling odors – a comparison

HEPA filters

While HEPA (high-efficiency particulate air) filters are designed to deal with large particles, they do not remove odors, chemicals, gases or VOCs. This means they are primarily ineffective for odors. Making matters worse, HEPA filters may actually serve as a source for musty, unpleasant odors. When pollutants such as bacteria and mold are trapped on HEPA filters, they may multiply over time if filters are not replaced, which can increase unpleasant smells.

HEPA filters with UV-C light

Whereas a pure HEPA filter may serve as the dark, damp, breeding ground of choice for bacteria, mold, and mildew, HEPA filters equipped with a UV-C germicidal lamp may be better served. UV-C stands for ultraviolet-C, a type of light which kills microorganisms by effectively making it impossible for them to reproduce. However, the effectiveness of UV-C light air purifiers remains unclear, as it would require a high dose of light and contact time for mold and bacteria to be destroyed.

Even as this option may claim to be better for reducing musty odors in your home, the effectiveness of using UV-C to reduce odor is ambiguous at best and has been shown to produce ozone, a harmful pollutant. So all in all, HEPA filters with or without a UV-C light are not viable options when seeking to reduce odors in a room.

Carbon air filters

Filters that use activated carbon to absorb airborne chemicals, specifically VOCs that make up odors, are a viable option for removing some odors from the air. However, their effectiveness is dependent on a few factors, which should be considered when using this method.

Firstly, the amount of carbon used in the air filter will drastically change the effectiveness of carbon air filters in removing odors, and the complexity (thickness) in carbon structures within the air filter itself has a massive effect on the filter’s overall capability. Oftentimes, the thin and inexpensive carbon filters common on the market are quite ineffective at removing odors, chemicals and pollutants from the air. Therefore, you may want to consider the amount of activated carbon (in pounds) that is present in the air purifier when it is an option.

Secondly, carbon air filters have potential drawbacks because of a process known as off-gassing. This is when the carbon inside the filter becomes saturated or otherwise disturbed by a rapid change in humidity or temperature, for example, which may cause the filter to release the VOCs back into the air. If carbon filtration is preferred, it is recommended to get a higher weight of carbon and to replace filters when saturation occurs, though off gassing may occur regardless of the weight and saturation of the filter.

Molekule (PECO) technology

Though carbon filtration is a decent option for odors, there is another long-term option that can help deal with odor-causing VOCs in the air by destroying airborne chemicals at the molecular level. This method of air purification, called Photo Electrochemical Oxidation (PECO), was developed over two decades by research scientists and enables the Molekule air purifier to help remove odors from the air. This becomes even more important when the VOCs in the air are harmful, as the Molekule air purifier will destroy these harmful airborne chemicals by breaking down molecular bonds.

Molekule PECO technology eliminates odors by generating free radicals that break down all VOCs, including those that cause smell. This means that Molekule destroys bad smells which range from unpleasant to physically harmful, and unlike carbon filters, Molekule does not simply trap gases but actually destroys them.

To learn more about independent testing and confirmation of Molekule vs. VOCs, see “Third-Party Confirms Molekule Air Purifier Destroys VOCs” here at this link.

Odors are airborne chemicals too small for most air purifiers

The smell of rotting food and the toxic gas giving cigarette smoke its distinct scent are examples of volatile organic compounds (VOCs), which traditional HEPA filters cannot mitigate. Carbon filtration is one decent option for odors, though it requires a good amount of carbon and drawbacks include the possibility of VOCs off gassing, or re entering the air in everyday scenarios.

Because the gases that imbue our homes with the occasional bad odor are so tiny, mechanical filtration like HEPA filters cannot remove them, and traditional gas-phase filtration like carbon filters simply trap and do not permanently remove them. The Molekule PECO technology is the only air purifier technology that can effectively destroy VOCs, the airborne chemicals that make up odor.

Air purifiers may combat some odors, but cannot act alone

The answer therein is not to mask odors with other more pungent fragrances, or to use an ineffective HEPA filter, but to address the entire problem by first removing the source of the smell as much as possible. Using an air purifier that is effective against odors will help you deal with lingering and unpleasant smells in your home after everything has been done in terms of removing mold, etc. and regular cleaning. Because even today, the best air purifiers still will not do your laundry.

Our solution

Alongside direct intervention to remove the source of the smell, whether it be mold or strong kitchen odor, using certain types of air purification technology can help. The Molekule (PECO) technology is the only air purification solution that effectively destroys volatile organic compounds (VOCs), which are the airborne chemicals that make up bad smells in your home. Molekule destroys mold, bacteria and pet dander as well, which can also contribute to unpleasant smells. Bad odors are not a mundane problem but a legitimate one, a part of a family of airborne chemicals called VOCs, many of which are harmful and we should not be breathing.

Smells are tricky, and not all air purifiers can be trusted to remove unpleasant odors. Luckily, emerging technologies are facilitating change in the way we clean our homes and our air, and Molekule is excited to be at the forefront of improving indoor air quality.