Why Is My Air Purifier Crackling?

Air purifiers are an essential household appliance in many American homes. While you can ignore some sounds they make as they work, others like crackling may be uncomfortable. So, why is your air purifier crackling? 

The occasional crackling sound occurs when the air purifier traps a larger particle. You can compare it to when a bug zapper contacts a bug. Constant crackling is a sign to clean the device or dry all the parts properly. 

This article considers whether it’s okay that your air purifier is making some noise. I also discuss why your air purifier is crackling and popping and how to fix a noisy air purifier.

Is It Okay That My Air Purifier Is Making Some Noise?

Noise is an unwanted sound, and it is subjective—your noise is someone else’s sound and vice versa. Air purifiers work by sucking in air, trapping pollutants, and releasing clean air into a space. Since there’s no absolute way to tiptoe air, air purifiers will make some noise.

They produce background or ambient noise while working, which is normal. However, an air purifier makes various sounds or noises, and some indicate problems with the device.

To know the noises that should concern you, here’s a description of noises an air purifier can produce:

  • Whispering and humming: These are the device’s normal operating noises when running at a low fan speed or just working.
  • Beeping: Beeps and flashes are a standard means of communication for air purifiers. A beep is typically a short high-pitched tone, often showing the need to replace your filter. It may also come with a persistent flashing light. A beeping noise from a working purifier can also mean you need to reset the device.
  • Crackling: This sounds like a short series of sharp, brief noises. If your air purifier crackles, bursts or sparks while operating, it means that it has trapped a large particle.
  • Rattling or clicking: This describes a sharp, brief, and normal motor noise the device produces during calibration.
  • Whistling: Damaged or defective air filters are the source of whistling noises. It is especially so if the whistling starts before the filter has worked enough to get dirty or right after installation. If the unit begins to whistle after the filter gets dirty, it’s probably clogged in a pattern that’s causing it to whistle.
  • Hissing: It’s usually because of the air purifier’s fan turning off, and it’s a harsh sound. It comes from the sensor as it slows down when you turn off the air purifier.

 In essence, humming, whispering, and beeping are normal operational noises. On the other hand, hissing, rattling, whistling, or crackling noises usually require repairs or routine maintenance.

Factors Affecting the Noise Volume

Air purifiers typically have differing noise volumes, and these are the factors responsible:

The type of air purifier 

You’re more likely to notice the noise from a portable air purifier than a whole-home air purifier. Whole-home air purifiers install into your home’s HVAC (heating, ventilation, and air conditioning) system—often away from the living spaces. 

The basement, utility closet, garage, or other housing for the HVAC usually contains whatever noise the unit produces, making it less noisy.

The air purifier’s operation speed

An air purifier’s fan is an integral component of the unit that can affect its air cleaning efficiency. Running the unit at the highest fan/operating speed results in more noise, and it’ll clean the air in a room faster. In contrast, using the air purifier at the middle or lowest fan/operating speed results in less noise and slower cleaning efficiency.

The air purifier model

Some models are louder than others, which may be because of the type of purification technology it uses. For example, air purifiers with a HEPA filter (on high speed) are louder than ionic air purifiers with the fan turned off. 

The Vornado AC is probably the loudest model. Its volume at the middle or low fan speed is higher than other models’ highest speed. Conversely, users have crowned the Levoit Vital 100 Air purifier as one of the quietest in the market.

The air purifier’s location

If you place an air purifier in your bedroom when sleeping, it’ll be noisier than in a room not in use. This is because a room with wood floors and high ceilings will amplify the air purifier’s noise. On the other hand, a room with furnishings and carpets will absorb the noise.

Why Is My Air Purifier Crackling and Popping?

Crackling and popping sounds are especially common in electrostatic air purifiers. They create an electric field to charge particles in the air sucked in by the unit’s fan. These charged particles proceed to a second chamber, falling on oppositely charged plates.

There’s a burst of energy when each particle hits the plate. A large particle hitting the plate can create enough energy to produce an audible pop or crackle. It’s the same sound a bug zapper makes when it hits bugs.

While these sounds are normal, excessive crackling and popping may point to issues with your air purifier. Two causes of excessive crackling and popping noises are:

A dirty filter

When your electrostatic air purifier begins to sound like a bug zapper in the Amazon rainforest, it usually means dirty filters. Of course, if the air is dry and dusty, it’s more proof of a dirty filter. Cleaning the filters or plates may be easy, but it’s best to consult the manual for instructions on dismantling. 

To make things easier, you can also take pictures before removing a part so you can remember how to reassemble it.

Moisture in the air purifier

The popping noise you hear with dry air doubles up in high humidity. Moisture in the air can short-circuit the system by condensing on the electrode wires and electrodes. If you don’t dry the plate properly after cleaning, the residual moisture can also contribute to short-circuiting the system.

Consequently, the pops occur so closely together that they become a crackling noise. Wiping the electrodes and their wires with a dry rag will stop the crackling.

How Do You Fix a Noisy Air Purifier?

Fixing a noisy air purifier is possible and easy when you know the noise source. Below is a discussion of some causes of noisy air purifiers and how to fix them:

Incorrectly installed filters

Besides your air purifier’s filter indicator light, excessive noises can point to an incorrectly installed or malfunctioning filter. If the problem with the filter is extreme, the air purifier may stop working altogether. Fixing this issue involves:

  • Turn off your air purifier and unplug it from the power source.
  • Open the air purifier’s front or rear grill and remove the air filter from the housing.
  • Check if you installed the filter correctly—the airflow arrow should point in the right direction.
  • If you installed it wrongly prior, reposition the filter correctly.
  • Close the front grate cover carefully.
  • Reset the air purifier by pressing the Clean/Reset filter button.

Dirty or clogged filters

A clogged filter will overload the air purifier’s engine. As a result, the engine has to work twice as hard to suck in and recirculate the air in the room. It results in unusual noises like spitting, coughing, and popping.

Besides the discomfiting sounds, your filter won’t work at optimum capacity, leaving your air dirty. As usual, your air purifier’s filter indicator light will come on when it’s time to replace the filter. Here’s how to replace your filter:

  • Turn off your air purifier and unplug it from the power source
  • Open the front or rear grill cover and remove the old filter—it’s probably gray or black.
  • Slot in the new filter and ensure the arrow points in the right direction. If the filter doesn’t have an arrow, follow the manual for the correct installation instructions.
  • Close the grill cover and reset the filter change indicator according to your model.

Debris in the air purifier

Debris comprises fragments from an object that’s been destroyed, and it can increase an air purifier’s noise if it enters the unit. Therefore, a general caution for all air purifiers is to avoid inserting or putting foreign objects into the device.  

They disrupt the normal dynamics of your air purifier and, if left in place, they may destroy the device. Here’s how to solve the debris problem:

  • Turn off your air purifier and unplug it from the power source.
  • Open the grill cover of the air purifier or dismantle the entire unit if necessary.
  • Check for debris and foreign objects or dust within the housing.
  • You can use a brush attachment with your vacuum cleaner to clean within the housing. If your filter isn’t clogged, you can also clean it with a vacuum cleaner.
  • Close the grill cover or reassemble the unit.
  • Reset the air purifier.

 Other causes of a noisy air purifier are the model, fan speed, and location. If your model is loud, you can replace it with a lower decibel (dB) model. You can also alter your air purifier’s fan speed and location according to your requirements.

If the noise persists after troubleshooting with the methods above, contact the manufacturer for further help. Most importantly, look out for the noise level of an air purifier when making a purchase. Since manufacturers aren’t mandated to state their product’s noise levels, I recommend selecting models that display theirs.