How can you tell if your air purifier is working? Could the clean air you’re breathing be just a placebo? Here are 6 signs you can look out for.

If you’re anything like me, and 60% of the world’s population, you probably live in the city, so you don’t need me to tell you how polluted the air we breathe, really is.

Be due to factory exhausts or rush hour traffic, it’s undeniable that we’re in constant exposure to harmful chemicals.

This is where air purifiers come in.

As you probably already know, these appliances are great at removing unwanted, filthy particles from our living spaces. When working properly, not only do they provide us with cleaner air, but also suck in allergy-causing elements, such as pollen.

They’re truly something else.

Having said that, how can you tell if your air purifier is, in fact, working properly? How can you know that the newfound feeling of clean lungs is not just a placebo?

Simple, you need to watch out for certain signs.

In theory, every air purifier should work straight out of the box, and all models should be equally efficient. But things always go a little different in practice.

I want to help you rule out any abnormalities in your appliance, so that you can be sure that both you, and yours, are breathing the cleanest possible air. This is why I’ve prepared the list below, including all the tell-tale signs of a properly functioning unit.

Are you ready? Let’s dive in!

Man working with an air purifier next to him
Air purifiers can refresh stale air, reducing the chances of health issues caused by indoor pollutants, which can trigger respiratory infections.

Identifying a Malfunctioning Air Purifier

There are many things you can try to verify your machine’s functionality. From something as obvious as listening for the fan noise, to more complex tests like buying an air quality meter from an online marketplace.

As stated above, if you bought your air purifier from a reputable vendor, there’s no reason why it shouldn’t work properly, but there’s always room for human error, and improper operation.

Sometimes your air purifier might be fine, but you could be using it incorrectly. Once we’re done covering the signs of proper functioning, I’ll provide you with a couple of best practices to make sure you’re always using your unit in the most efficient way.

#1 Adequate Airflow

Check the top of your appliance for airflow

This might seem a little obvious, but we’re trying to cover all bases here, right?

The easiest way to tell whether your air purifier is working, is by gently placing your hand over the fan exhaust and feeling for air flow. If you feel nothing, it doesn’t necessarily mean that the appliance is not working. Try setting the fan to the highest level, and test again.

Now, I’d be remiss not to mention that airflow does not mean adequate air cleaning. This sign only means that the unit is, in fact, functional, but in order to determine whether it’s actually cleaning the room, we’ll have to run more tests.

#2 Fan Noise

Listen carefully to your appliance

If you’ve read our other articles about how to make your air purifier quieter, chances are you’ve already implemented the solutions we suggested. If that’s the case, your unit should be operating at low noise levels.

While this is, for the most part, a good thing, it can make it difficult to tell if the appliance is working.

Depending on your fan settings, your air purifier could be running perfectly, but making no noise, thus creating the illusion of a malfunction. Before calling a technician or taking a look at your warranty, make sure to listen carefully.

More often than not, and especially if you set your machine to work on auto mode, it could get louder or quieter as the day goes by, which could be mistaken for intermittent functioning.

Solution: Take 5 minutes from your busy day and approach your air purifier. Turn off the TV and any other unrelated noise sources that could make it hard to listen to your appliance’s fan.

If you still hear nothing, try bumping up your fan levels momentarily, and listen again.

#3 Dirty Filters

Dirty filters could prove your unit is working

Air purifiers need constant cleaning, and dedicated maintenance sessions, there’s just no way around that.

As you probably know, most manufacturers recommend that you clean your filters at least once a month, and change them every three to six months.

This will not only guarantee that you’re always using your machine under the most hygienic conditions, but also prevent other neglect-related problems, such as overheating.

Moreover, checking your filters regularly is not only a best practice to keep them clean, but also an unmistakable sign of adequate operation.

How so? Let me explain.

Let’s say you bought new filters for your air purifier, and have been using your machine for a couple of weeks now. If your unit is working properly, the next time you open it to clean the filter, it should have debris, and dirt on it, right?

Sparkling clean filters that are over a month old are an obvious sign that there’s something not working properly within your air purifier.

#4 Bright Indicator Lights

Inspect your indicator lights

This will vary from model to model, and from manufacturer to manufacturer, but in most cases, you should be able to find some indicator lights at the front of the appliance.

These are in place to let you know that the machine is working, cleaning, or having problems.

Again, some more sophisticated models might have other indicators pertaining to maintenance, and other complex functions, but your everyday air purifier should at least have the one “On/Off” light.

If you keep your appliance in a very bright room, it could be difficult to see these lights during the day. Whenever possible, try to darken the room, and check again. Provided that you’re having trouble reducing the light levels in the area, you can also wait until nighttime.

New model of air purifier with blue led ligths
If your air purifier is in a bright room, it may be difficult to detect the light that says that the appliance is working correctly.

#5 High Air Quality Levels

You can use a meter to test air quality in your home

So far, we’ve only covered the tell-tale signs of an operating air purifier, but even an appliance that turns on, could be failing to clean the air adequately.

This is the main difference between “operational”, and “functional”.

Your air purifier could be showing all the signs of correct operation, such as fan noise, blinking lights, and airflow, but even then, it could still be leaving harmful pollutants in your breathing space.

In theory, all models should work the same, but in practice things can always go very differently.

Just it happens with any other appliance out there, depending on your air purifier’s brand, your unit could be more or less effective at cleaning the air.

And while some people might tell you differently, it’s likely just a sales pitch.

The best way to accurately tell whether your air purifier is actually working and cleaning the air, is by using a CO2 meter. As its name suggests, this meter is great at detecting excessive amounts of carbon dioxide, and other harmful pollutants in a determined environment.

If the CO2 readings on your meter are very high, your machine is not doing its job as it should.

#6 Eradicated Symptoms

Lessened allergy or asthma symptoms are a good sign

Lastly, listen to your body.

If you suffer from any respiratory conditions, such as allergies, or asthma, your air purifier has probably been a godsend.

When working as they should, these appliances should remove pollen, and dust from the air you’re breathing, thus improving your health, and lessening your symptoms. If you feel much better since you bought your unit, chances are it’s working perfectly.

Monitor yourself, and you’ll find the answer.

What Can You Do to Make Your Appliance More Efficient?

As stated above, your air purifier should work wonders right out of the box, but there are definitely some best practices that you can implement while using it that will make it more efficient, and provide you with cleaner air.

Some Of Them Are:

  • Use your unit in small rooms
  • Disable auto mode
  • Clean your filter regularly

Most models are designed to clean specific air volumes, which means that, a unit that effectively removes pollution from a small room, might not work as well in a large living room.

Especially when set to “auto mode”.

I know how this feature might seem very convenient, but there have been several studies that show that this feature is not as effective for cleaning the air, as setting a constant operation level manually.


Your air purifier is truly remarkable, but how can you tell that it’s actually doing its job?

As you’ve learned in this piece, there are several tell-tale signs to look out for in order to confirm that your appliance is, in fact, both operational, and fully functional.

More often than not, all you need to do to find the right answer, is be a little more conscious when operating your machine, and rely on your senses. There’s no reason why your unit should not be working properly, but it’s always better to be sure. 

Thank you for reading. If you found this article helpful, why not keep the learning going through our other incredible resources below?

You can breathe easy now!