How to Tell if an Air Purifier is Working

Modern air purifiers are very efficient machines when it comes to improving air quality and the difference is usually noticeable after the first 30 minutes of use. But, we sometimes tend to be less objective when we’re messing around with a new device we had just bought, so we need some foolproof ways to check if the air purifier is doing its job properly.

Oftentimes we’re either overly excited about a new air purifier and attribute some positive change to it, or we’re too skeptical and think that nothing is happening. When the unit is active, the change in air quality isn’t visible to the naked eye, so how can you know if it’s working?

In this article, we will discuss the methods that you can employ to correctly test your air purifier, but if you’re in the market for a brand new whole-house air purifier, check our guide and reviews.

The Indicator

Most new, albeit more expensive air purifiers, feature air quality indicators on the device itself. But, if such a feature is not present on your unit, you can always check the filter replacement indicator. If it’s lit up, it means that the filter inside needs cleaning or replacing and that the air purifier isn’t working up to its maximum capacity. If that was the case, though, we’re pretty sure you’d notice the decrease in performance.

Manually Check the Filter

If in certain instances, the indicator isn’t working properly or you’re someone who prefers a more hands-on approach, you can always manually check the filter inside.

Simply disassemble the air purifier on a plastic sheet, or outside, to prevent spilling the built-up dust. If there’s a lot of it on the filters, chances are the device has been working properly for some time now and it’s due for a filter change. Keep in mind that backed up filters can be a source of air pollution as well and replacing them usually resolves the issue.

On the other hand, if there’s not that much debris and weeks have passed since your purchase, it probably hasn’t been doing its job and you might want to contact the manufacturer.

Chemical Tests

One of the external tests you can conduct is via a chemical test kit. These come in many different versions and can test for mold, formaldehyde, and other VOCs in the air. You can easily find these products on Amazon or in retail pharmacies.

The optimal way to test if your air purifier is working correctly with a chemical kit is to turn it off for an hour or two, then conduct one test. Make sure you write down the results and wait for at least 24 hours. After 24 hours have passed, turn your air purifier on and let it run for about 30 minutes. Following that, do the second test and compare the results. If the results from the second test are worse or similar to the first one, your air purifier might not be functioning properly.

Air Quality Monitor

Another external testing you could conduct is through a digital air quality monitor. Nowadays these are included in most of the more advanced air purifiers, but if that’s not the case, or if you’re second-guessing their accuracy, you can opt for a separate air quality monitor.

Digital air quality monitors can give you an accurate representation of the amount of particulate matter, both indoors and outdoors. In terms of features, these devices vary a lot, ranging from basic particulate counters to devices with wi-fi connectivity, mobile apps, etc.

This is by far the most expensive option and it’s not very practical since it involves buying a whole separate device. But, if you want on-hand data about the air quality in your room from multiple sources, you might want to opt for it and have a reliable revision system for your air purifier’s efficiency.

Other Checks

If none of the above seem suitable for you, there are other simpler checks you can do to discern whether your air purifier is working properly.

In lieu of the chemical test, you could simply introduce foreign particulates in the air and see how well the air purifier deals with them. If, for example, you’re living in an urban area, open the windows for a while, then close them and turn the device on. If you notice a difference within 30 minutes, the air purifier is probably doing its job.

Another check you could do involves examining the airflow. Filter based air purifiers have a fan that draws in air from the room and then blows it out after passing it through its filters. You ought to check both sides and see if there’s sufficient airflow. If the unit is on, but you can’t feel the ‘breeze’ on one side or the other, then the purifier isn’t working properly. The best way to perform this check is on the air purifier’s maximum speed setting.


As you may have read, there are many checks you can perform to tell if an air purifier is working accordingly. It all comes down to which one you deem the most trustworthy and whether you want to conduct an extensive examination or just get a ‘second opinion’ on the air purifier’s efficiency.

If you happen to own a device with air quality indicator features, it’s a no-brainer to go by those indications unless you can truly sense that something’s off in regards to its function. After all, that’s why those indicators are included.

But if your air purifier doesn’t have such facilities, you can check the filter by disassembling the device, check the airflow near its fans or opt for more external inspection methods. These include buying an air quality monitor or chemical test kits.

We hope you found this article helpful and that now you have all the know-how necessary to tell if your air purifier is working. Should you want to read up on more information regarding air quality or find yourself looking to buy a new air purifier, visit our blog where we have a variety of useful articles and reviews!

Last update on 2024-07-17 / Affiliate links / Images from Amazon Product Advertising API