Can air purifiers prevent colds and the flu?

In the midst of the winter season, cold and flu viruses seem to be omnipresent in public places. Although it may be impossible to avoid falling ill, a great way to reduce your risk is to invest in an air purifier in your home or workplace. How are colds and the flu spread? Can an air purifier for colds and the flu help reduce transmission of these common illnesses? Read on to learn more about how an air purifier can contribute to a healthier indoor environment during cold and flu season.

A man with his hand on his head sitting on his bed

Cold and flu season

How do colds and the flu spread?

The common cold and the flu (or ‘influenza’) spread in the same way that many pathogens and virus particles do, including COVID-19. When a person infected with an illness talks, sneezes, coughs, sings, or even breathes with an open mouth, infected aerosols are released from their mouths into the air. These contaminated, microscopic respiratory droplets are then inhaled by another person in close proximity, especially in public places with high crowd density. Aerosols may also land on surfaces and/or objects and once another person touches the infected surface or object, the infection can easily make its way into an uninfected person’s body.

Infected respiratory droplets also stay airborne for extended periods of time, often long enough to reach ceiling ventilation. Additionally, sneezed aerosols can travel further than expected. A 2014 study by MIT found that droplets that measure 100 micrometres in diameter emitted by a sneeze travel five times farther than previous studies had anticipated, and droplets measuring 10 micrometres travel 200 times farther1!

What is cold and flu season?

We all know the symptoms well: a runny and stuffy nose, coughing, sneezing, headache and/or sinus pressure, and a sore throat. With such similar symptoms, it may be hard to tell the difference between a cold and the flu. Although they are both extremely contagious respiratory illnesses, they are, in fact, caused by different viruses.

The flu is caused by the influenza virus. The common cold may have a host of different viral causes, some of which may include rhinoviruses, seasonal coronaviruses, and parainfluenza. The flu usually has a much more intense impact than a cold does, and a typical giveaway in differentiating between the two illnesses is that infected individuals are significantly less likely to have a runny nose with the flu than those with a cold. The flu may also lead to serious complications like respiratory tract infections and even respiratory death, especially in vulnerable individuals2.

The common cold is typically more common in winter, but it can be spread and caught all year round, regardless of age or health status. The flu can also be caught all year round, but flu activity is elevated from October to April, especially in winter, in the Northern Hemisphere.

Comparison of cold vs flu symptoms

Source 2

Who is at risk and what are the major contributors?

Anyone can catch a cold or the flu, regardless of health status. On average, most adults will come down with a cold two to four times per year, with children impacted by colds six to nine times per year on average. School children, employees working in schools, and office employees in general are at the highest health risk, with colds responsible for millions of sick days every year.

Some of the biggest contributors to falling ill with a cold are:

  • Exposure to a high density of people, especially children, particularly in public places
  • Accumulation of dust in the home or office
  • Exposure to air with humidity levels that are too low or too high (cold and dry air), an environment in which studies have shown that viruses and bacteria thrive (especially COVID-19)3,4

The flu is also quite common with around a billion registered cases of seasonal influenza per year5.

How indoor air pollutants impact illness?

Studies have shown that the presence of indoor air pollutant particles can make it easier to contract illnesses and for them to be aggravated and prolonged. One 2020 study found that indoor air pollution and poor indoor air quality (IAQ) lead to more serious illness and lethal forms of COVID-19. Chronic exposure to air pollutant particles also aggravates health risk, making it more complicated to recover from and to be reinfected by COVID-19 and other respiratory viral infections6.

A woman sitting on the floor blowing her nose

How to reduce the risk of colds and the seasonal flu?

Create healthy habits in your indoor environment

Maintaining a healthy indoor environment in both public and private places is essential for reducing the impact of colds, the flu, and other pathogens. There are several measures you can take to promote respiratory health and ward off infection of respiratory illness:

  • Regular cleaning: keep your home clean and free of dust and debris by hoovering and dusting regularly, paying close attention to areas where dust and allergens may accumulate (carpets, curtains, and upholstery)
    • Wipe down and disinfect keyboards, phones, and other high-touch items and surfaces regularly – germs can live on surfaces for up to 24 hours!
  • Ventilate: ensure adequate ventilation in your home and office by opening windows whenever possible to allow fresh air to circulate and reduce indoor air pollutants
  • Maintain ideal humidity levels: do not drop humidity levels below 30% nor exceed 50%
  • Practice good hygiene: keep your hands clean by practicing diligent handwashing with soap and use alcohol-based hand rub/sanitisers
  • Be diligent when you are sick: protect those around you from contamination by covering your mouth whilst coughing or sneezing and/or wear a face mask and avoid contact with others/stay home from work or school
  • Boost your immune system: get a good night’s sleep, eat a balanced and nutritious diet, avoid stress, exercise regularly, take hot showers with lots of steam, and take vitamin C supplements

Prevent the flu at school

As mentioned above, public places like schools are breeding grounds for cold and flu transmission. In order to reduce health risk at school, be sure to regularly clean doorknobs and taps. Ensure that your child’s school or childcare program adheres to routine cleaning procedures, especially for touched objects and surfaces. Your child’s school should also be well-equipped with tissues, soap, paper towels, alcohol-based hand rubs and sanitisers, and disposable wipes. Most importantly, if there is an outbreak of the flu or a cold is going around, sick students and staff members should stay home. It is also recommended to receive a flu vaccination for both children and adults.

Prevent the flu at work

It is also common for workplaces to experience high cold and flu transmission. Reducing cold and flu transmission at work follows the same principles as those for reducing outbreak of illness in other public places. Frequently-touched surfaces and objects like doorknobs, keyboards, and phones should be wiped down regularly with disposable wipes. Your office should be well-stocked with soap, tissues, paper towels, and alcohol-based hand rubs/sanitisers. During outbreaks of the flu, clean your mobile phone and avoid handling it if possible. Stay home if you are feeling ill.

Use ventilation and an air purifier to fight colds and the flu

One of the best forms of flu prevention during flu season is to make a healthier indoor environment. This will reduce the spread of seasonal illnesses like common colds and the flu virus caused by airborne viruses and also illnesses caused by bacteria. This can be done in two ways:

  1. Ventilate your space and encourage air flow. An indoor space with insufficient ventilation leads to a build-up of infected particles, other airborne contaminants, and even humidity where germs thrive. This increases the risk of inhaling infected respiratory droplets.

  2. Use an air purifier for colds, the flu, and other pathogens. Air purifiers containing medical-grade filtration systems can help reduce germ transmission by removing airborne microorganisms. In addition to viruses and bacteria, air purifiers also help eliminate other airborne contaminants that can exacerbate respiratory issues and weaken the immune system. Dust and dust mites, pet dander, pollen, and mould spores are common allergens and irritants that can trigger allergic reactions and respiratory symptoms, especially asthma attacks. By performing continuous filtration of these pollutants, air purifiers create a cleaner and healthier indoor environment, reducing the likelihood of cold and flu transmission.

A woman putting on a mask

How to choose the right air purifier for cold and flu season?

Consider its filter

Not all air filtration devices are capable of combatting harmful airborne particles like viruses and bacteria and warding off infection. The two most important technologies in an air cleaner to seek out when fighting against germ transmission are 1) a medical-grade HEPA filter and 2) UVC sterilisation technologies. HEPA filters are third-party tested to guarantee the removal of 99.97% of air pollutant particles down to a size of 0.01 microns in a single pass. This includes all microorganisms found in your indoor environment. UVC sterilisation technologies are commonly used in hospitals to keep pathogen transmission low.

Eoleaf, for example, offers devices containing 8 different air filtration technologies as part of its medical-grade filtration system. This also includes an activated carbon filter to eliminate harmful odours, gases, and chemicals like volatile organic compounds (VOCs).

Consider room size

Air purifiers must be properly sized in order to properly filter all of the air in your indoor space. This is why Eoleaf offers three sizes, allowing our devices to cater to rooms of any size:

Consider air purifier performance

Two metrics to keep in mind when choosing an air purifier for colds and the flu are Clean Air Delivery Rate (CADR) and Air Changes per Hour (ACH). CADR is used to measure the performance of an air purifier and indicates whether or not the device will be powerful enough to clean your entire space. The higher the CADR, the better! ACH indicates how many times an air purifier can filter a room’s volume of air per hour. The CDC recommends an ACH rating of at least 5 in occupied spaces, especially during cold and flu season, for optimal air filtration. Similarly to CADR, the higher the ACH, the better.

Consider noise level

A high-quality air purifier should always be quiet. It should never disturb you whilst you work, study, or sleep. The decibels of an air cleaner should never exceed 60 dB, even when left running on its highest fan speed.

Protect your indoor spaces from germ spread with Eoleaf

Air purifiers play a crucial role in creating a healthier indoor environment and reducing the risk of cold and flu transmission. Let our air purification experts here at Eoleaf team provide you with peace of mind peace of mind during cold and flu season. Reach out to our team anytime with questions regarding your specific needs. We have also created an in-depth Buying Guide to help you consider all of the factors required in choosing an air purifier.

Eoleaf's AEROPRO 100 air purifier next to a white chair

Frequently asked questions

How often should air purifier filters be changed during cold and flu season?

Eoleaf devices come equipped with high-quality filters that only need replacing once a year. However, it is very important to change your filter on a regular basis. Continuing to use an air purifier with a saturated filter could release air pollutant particles back into the air!

What is the ideal placement for an air purifier to prevent infections from colds and the flu?

An air purifier is best placed in a location where it will not be impeded by furniture, corners, or shelving. It should have optimal air flow to allow it to properly filter the air in the whole room. Place your air purifier in a room that you use regularly: the kitchen, the bedroom, and/or the living room are all excellent choices.

Can an air purifier replace other flu prevention measures?

An air purifier helps eliminate airborne germs from the air, but it does not and should never replace regular cleaning and sanitising measures. During periods of seasonal epidemics or pandemics like COVID-19, the CDC recommends using an air purifier in tandem with mask-wearing for optimal protection from pathogen spread.

What are healthy habits to help protect against flu infection?

A few things you can do to ward off the flu and other pathogens are to ensure that you get lots of sleep, eat a healthy diet, exercise regularly, keep a clean home, wash your hands thoroughly and frequently, ventilate your home, and stay home when you are not feeling well to protect those who are vulnerable. Reducing concentrations of indoor air pollutants with an air purifier is also an excellent way to protect yourself against the flu.

Are there any specific features to look for in an air purifier for flu season?

An air purifier for cold and flu season should contain two technologies in particular: 1) a HEPA-certified filter and 2) UVC sterilisation technologies. These technologies are your first line of defence in removing airborne germs. It is even better if your air purifier is equipped with other technologies (Eoleaf’s devices contain 8!).

Is it safe to use an air purifier around children and the elderly during flu season?

Absolutely! Using an air purifier around children and the elderly is an excellent and highly-recommended way to protect two of the most vulnerable population groups against pathogen spread and the dangers of indoor air pollution. Pregnant women and immunocompromised individuals are also highly vulnerable and should be protected from indoor air pollution with an air purifier.


1 Dizikes , P. (2014, April 8). In the cloud: How coughs and sneezes float farther than you think. MIT News.

2 Centers for Disease Control and Prevention. (2022, September 29). Cold versus flu. Centers for Disease Control and Prevention.

3 Marina Nieto-Caballero, Ryan D Davis, Eddie Fuques, Odessa M Gomez, Erik Huynh, Alina Handorean, Shuichi Ushijima, Margaret Tolbert, Mark Hernandez. Carbohydrate vitrification in aerosolized saliva is associated with the humidity-dependent infectious potential of airborne coronavirus. PNAS Nexus, Volume 2, Issue 2, February 2023, pgac301.

4 Yang W, Marr LC. Mechanisms by which ambient humidity may affect viruses in aerosols. Appl Environ Microbiol. 2012 Oct;78(19):6781-8. doi: 10.1128/AEM.01658-12. Epub 2012 Jul 20. PMID: 22820337; PMCID: PMC3457514.

5 World Health Organization. (2023, October 3). Influenza (seasonal). World Health Organization.

6 Domingo JL, Rovira J. Effects of air pollutants on the transmission and severity of respiratory viral infections. Environ Res. 2020 Aug;187:109650. doi: 10.1016/j.envres.2020.109650. Epub 2020 May 11. PMID: 32416357; PMCID: PMC7211639.

Eoleaf's range of air purifiers

1 of 4