How Long for an Air Purifier to Clean a Room?

Lawrence Bonk Avatar

Written by:

Updated Jul 7, 2022 1:52 PM

If you are thinking of buying a top-rated air purifier or replacing a pre-existing model, you may be wondering just how long for an air purifier to clean a room? We are here with answers to this question and more.

KEY TAKEAWAYS:

  • Generally speaking, an air purifier can clear pollutants from an average-sized or small room in 15 to 30 minutes.
  • For larger rooms, the purifier could take longer. We recommend keeping entry doors and windows closed for best results.
  • You should also be aware of furniture placement and other obstacles, as both can impact the efficacy of an air purifier.

How Long Does it Take for an Air Purifier to Clean a Room?

This metric will vary depending on a list of factors, see below, but a standard air purifier will take around thirty minutes to two hours to purify the air in a room.

Factors That Decide How Long an Air Purifier Takes

There are several things to consider when trying to calculate how long it will take for your air purifier to fully purify the air in your living space. Based on your needs, you can also decide how long you should keep your air purifier on.

Room Size

Of course, the size of the room itself will greatly impact just how long the air purifier takes to do its job. If you have placed an air purifier in a smaller room, such as an infant’s bedroom or a sunroom, the purifier can be finished with a purifying cycle in just 15 to 30 minutes or so. To speed the process up, you may want to keep any doors that lead to the room shut, and the same should be said of windows.

Insider Tip

If you have placed an air purifier in a smaller room, such as an infant’s bedroom or a sunroom, the purifier can be finished with a purifying cycle in just 15 to 30 minutes or so.

Purifying Power

The overall power and efficiency of your air purifier should also be considered as you calculate the time it will take for it to clear a room of polluted air. If you are deciding which air purifier to buy, take a look at the model’s rate of air changes per hour (ACH.) A high-quality air purifier should be able to clean a room four to five times per hour, though the industry standard is once every twenty minutes, which translates to three air cycle changes per hour.

Furniture Placement

When an air purifier advertises a set number of air cycle changes per hour, it is referring to tests performed by the manufacturer. These tests, however, were usually conducted in perfect settings in bare rooms with little to no obstructions. In the real world, there will be furniture, bizarre room shapes, and many other factors that can lower the purifier’s overall metric. If you have large items of furniture blocking many parts of the room, you may want to think about reshuffling the design of your room to better suit the air purifier.

Insider Tip

If you are deciding which air purifier to buy, take a look at the model’s rate of air changes per hour (ACH.)

Purifier Maintenance

Performing regular maintenance tasks on the air purifier and its air filters will increase its efficiency and its room air cycle change rate. We recommend cleaning the air purifier about once a month, and making sure to wipe away the vents with a microfiber cloth. HEPA filters last up to one year. You should remove and replace HEPA filters every six months to one year. As for reusable filters, you should remove them and clean them once every month according to the manufacturer’s instructions.

Pollutant Level

When a manufacturer is testing out the efficacy of an air purifier, it is typically tested to handle the average amount of air pollution. If you are experiencing an extremely high level of air pollutants in your home, you may notice that the purifier may struggle to keep up. The causes of these pollutants can vary, from wildfire smoke to intense mold outgrowths, and more. If the exterior environment is polluted, we recommend shutting your windows and trying to limit the amount of outdoor air that enters your home. Fan speed can affect an air purifier, but only if you’re running harder than recommended.

Take a Look at the CADR

Another metric to consider when measuring the efficacy of an air purifier is the clean air delivery rate, otherwise known as the CADR. This metric illustrates how much air a purifier can push into a room and how far its reach can go. Look for an air purifier with a CADR rating of 300 CFM, which will clean a room of 300 sq ft much faster than an air purifier with a CADR rating of 200 CFM or lower.

Warning

If you have large items of furniture blocking many parts of the room, you may want to think about reshuffling the design of your room to better suit the air purifier.

F.A.Q.

Someone in my household has a pet allergy. How can air purifiers help, and are they an effective solution?

Absolutely. Modern air purifiers have been purpose-built to reduce the severity of pet-related allergy symptoms.


How does my indoor air quality relate to the local outdoor air quality in my area?

There is an extreme correlation. Windows and doors lead to the outdoor, after all, so try to keep these entryways closed if you are experiencing poor outdoor air quality.


Where are HEPA filters used?

HEPA filters are used in a wide variety of air purifiers, vacuums, air conditioning units, heaters, and other major appliances. You will also find them in hospitals and related medical settings.



STAT: The CADR is a standardized test that shows how many cubic feet per minute an air purifier is able to move to clean out 80% of the pollutants in the air. (source)

Lawrence Bonk Avatar

Learn More About Air Purifier