Can you run an air purifier and humidifier at the same time?

This article discusses whether it is good to run an air purifier and a humidifier at the same time. Furthermore, this article also talks about how each of these devices work, and how to get the best out of them.

Can you run an air purifier and humidifier at the same time?

No, you should not run an air purifier and a humidifier at the same time. This is because both devices perform completely different functions, and running them together can impede the efficiency of both devices.

What do air purifiers do and why do you need one

Air purifiers, as the name suggests, are devices that are responsible for cleaning the indoor air, by getting rid of the pollutants present in it.

There are mainly two types of air purifiers, namely:

  • High efficiency particulate air (HEPA) filters
  • Air ionisers

These air purifiers can have additional components, such as a UV light chamber, activated charcoal filter, and so on, which are mainly designed for widening the spectrum of the device’s efficacy against various pollutants.

Many people wonder whether an air purifier is the right investment. However, in the current scenario, where air pollution is prevalent and worsening with each passing day, especially in urban areas, air purifiers are very vital.

Air pollution is the presence of undesired substances in the form of solids, liquids, or gases, which are suspended in the ambient air, and can adversely affect human health.

These pollutants can be especially harmful if present in the indoor environment. The average human being spends more than 90% of their total lives in an indoor environment, with more than 80% of it inside a building.

Indoor air, just like outdoor air, is susceptible to pollution. Indoor air can get polluted when pollution from outdoors infiltrates through openings such as doors, windows, cracks, seeps, etc.

Indoor air can also get polluted from indoor sources, which can arise from things such as furniture, household items, solvents and dyes, spores from mold and mildew, combustion of fuels and firewood, and hobbies/activities such as smoking, etc.

The pollutants generated from these sources have been shown to adversely affect human health, and continuous exposure to elevated concentrations can cause many serious issues, such as cancers, respiratory and cardiovascular disorders, and even death.

This is where air purifiers come in. They help to get rid of the pollutants in the indoor air, thereby keeping it clean and fit to breathe.


Working mechanism

Humidifiers are devices that increase the humidity of the indoor environment. These are generally used in dry seasons such as winter, when the relative humidity levels dip below the optimal range, which typically is between thirty to fifty percent.

There are two different types of humidifiers: cool-mist humidifiers and warm-mist humidifiers, which are also known as steam vaporisers.

They both contribute moisture to the air in the same way. Aside from personal choice, there isn’t always a benefit to one over the other.

Cool-mist humidifiers break up water into tiny particles that then enter your air as water vapor. The water starts cold and stays cold, so they can help cool your air, too.

Steam vapourisers heat normal water to its boiling point, then cool the steam and release them in the indoor environment. They can also be used with inhalants or essential oils that may be helpful for people with allergies or asthma.

How humidifiers help

As mentioned before, humidifiers make the room humid, which is essential in dry seasons. This is because dry air can act as an irritant to the nasal passage and the respiratory passage.

Furthermore, dry air can also contain particular allergens that can trigger asthma flare-ups, as well as cause issues such as:

  • Sore throat
  • Nosebleeds
  • Bronchitis
  • Sinus inflammation (sinusitis)
  • Cold
  • Influenza

Which type of humidifier should you invest in

Cool-mist humidifiers are safer than hot-water humidifiers because they do not utilise hot water, which might burn you if you drop it. As a result, they are safer to use in the presence of youngsters.

However, if the humidifier isn’t cleaned regularly or correctly, cold mist might transmit airborne germs or virus material. Before releasing steam, steam vaporizers boil away germs or pathogens in the water.

If you have children or if you have pets, a cool-mist humidifier may be the best option. If hot water from steam vaporizers is spilled, it might cause burns.

Why you should not run humidifiers and air purifiers together

As we’ve seen from above, air purifiers remove particles from the air, while humidifiers add moisture to the indoor air. When you run both devices together, the following things can take place:

  • Reduction in the efficiency of air purifiers
  • May not help with mold problem in the house

Let us discuss these in more detail.

Reduction in the efficiency of air purifiers

Excess humidity can cause a reduction in the efficiency of an air purifier when it comes to getting rid of indoor air pollution. This is because humid air is heavier than the air with the optimal moisture content.

Furthermore, humid air can also cause clogging in the filters of the air purifier, as shown in a study by Joubert et al in 2010, which investigated how humidity affected the HEPA filters in a nuclear reactor.

It was found that in the presence of excess humidity due to the steam produced in a nuclear reactor, the chances of a HEPA (High Efficiency Particulate Air) filter to get clogged, since humidity caused a pressure drop within the filters.

Similarly, if one runs an air purifier along with an air humidifier, the moisture can cause a pressure drop in the HEPA filters, which are the most common types of filters used in an air purifier. This in turn will reduce the efficiency of the device.

May not help with the mold problem in the house

Mold is defined as fungal colonies that grow in the form of multicellular filaments. Most of them are harmless in nature and cause minor allergic reactions other than the odor, but some can have serious implications on health if inhaled.

Mold growth usually occurs in a dark, humid, and cool temperature condition. Under such conditions, the growth of mold and bacterial microorganisms is favoured.

Certain areas in the house, such as basements, bathrooms, kitchens, and so on, harbor such conditions, thereby being an ideal spot for mold growth to take place.

Mold itself does not spread to other parts of the house. However, the spores that emerge from mold, which are basically the seed, are responsible for transmission of mold to other places.

However, since these spores typically have an aerodynamic diameter which lies in the cut-off range for an air purifier, these particles can be picked up from the indoor air, thereby reducing the risk of infection.

Not only this, but this also helps to keep in check the growth of mold and its spread to other parts of the house, since the spores that are responsible for doing so have been removed from the environment, thanks to the air purifier.

But when one uses an air purifier along with a humidifier, they not only reduce the ability of the former to remove the spores that are suspended in the indoor air, but also provide the adequate conditions for mold to grow and proliferate.

On the contrary, doing so can make the air purifier an ideal breeding ground for mold itself, since humid and dark conditions prevail within the air purifier itself, due to the humidifier.

This in turn can cause the mold spores trapped within the filter to start growing within the air purifier itself, which not only harms the device, but also can adversely affect the air quality of the indoor environment.

What is the ideal way of using an air purifier as well as a humidifier

If you want to bring the best out of both devices, it would be ideal to use the air purifier first for a while. Once the air quality improves, you can turn the purifier off for a while and then use the humidifier.

On doing so, your indoor air gets cleaned first, which also would help to get rid of any mold spores that could have infiltrated from the outdoor environment.

Once the indoor relative humidity level falls within the optimal range, it would then be ideal to turn off the humidifier, in order to prevent excess humidity from accumulating in the indoor environment, which in turn could also harm your health.

Other FAQs about Air Purifiers and Filters that you may be interested in.

Can air purifiers help with mold?

Should I turn on the ionizer on My air purifier?

How air purifier towers work?


It is not advised to run an air purifying device as well as a humidifier at the same time. This is because not only will the efficiency of the air purifier decrease due to clogging, it will also lead to growth of mold in the air filters.

Therefore, it is ideal to run the air purifier first in order to get rid of the pollutants from the indoor air, turn it off, and then run the air humidifier until the humidity levels reach an optimal level.

Air purifiers to consider

Air humidifiers to consider


Do humidifiers prevent mold and mildew formation?

No, humidifiers do not prevent the formation of mold and mildew. On the contrary, they can exacerbate the condition even more.

Mold and mildew only grow in humidity levels of more than 50 percent. However, using a humidifier will further provide the humidity levels required by the mold and mildew to proliferate, and also spread to other areas of the house.

Can humidifiers and air purifiers help to prevent COVID-19?

Yes, humidifiers as well as air purifiers can help to prevent COVID-19. The novel coronavirus can survive longest under conditions of low humidity levels and in polluted air.

Air humidifiers help to ensure that the humidity levels are at optimal levels so that the SARS-CoV-2 virus cannot survive for long.

Air purifiers, on the other hand, entrap the particles from the air that may contain the virus on their surface. However, both devices can only provide up to a certain level of protection and aren’t a foolproof solution.

Therefore, it is ideal to follow the safety protocols such as social distancing and practicing good hygiene habits in order to ensure that you as well as your loved ones are safe from contracting the virus.


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