An air purifier is only as good as the filter inside it. While some companies may claim to have filters that last for years or even forever, the truth is at some point the filter media will clog up. When the filter clogs you no longer have a machine that cleans air but one that makes noise and wastes electricity. It should be pretty obvious that changing the filter(s) in an air purifier is important, but have you ever wondered exactly why it matters?
Benefits of Timely Air Filter Replacement
There are a few reasons why regular filter replacement service is a wise decision. These include:
- Maintaining the air cleaning efficiency of the air purifier
- Prolonging air purifier service life
- Allowing the air purifier to work efficiently
If you want your air purifier working hard to remove airborne bacteria, allergens, pet dander and other tiny particles you need to maintain the filter(s).
Air Cleaning Efficiency
Each air purifier is designed to work with a specific air filter flowing at a certain air flow rate. In order for an air purifier to perform at its rated Clean Air Delivery Rate (CADR) the filter must flow freely. Fan motors, fan blades, fan speeds, internal ducting, and more are all designed around a certain air flow rate. When filter maintenance is neglected the bottleneck in the system becomes the filter itself. Some air purifiers equipped with HEPA air filters or other high-efficiency air filters use a pre-filter to capture any large particulates before they reach the main filter. In the case of the Intellipure Compact the pre-filter should be cleaned monthly using a handheld vacuum attachment. Don’t forget about the carbon filters used to remove volatile organic compounds (VOCs). These composite filters trap particles and nasty smells. Over time they become saturated and can no longer do their job.
Air Purifier Longevity
Regular maintenance can help your air purifier live a longer mechanical life. A clogged air filter is much more difficult to draw air through than a new air filter. This can lead to overworking the fan motor. It can even cause an overheating issue if the fan motor is designed to be cooled by air passing through the unit.
Energy Efficiency
The better the air filter flows, the easier it is for the fan motor to move air through it. Think of it as breathing through your open mouth versus breathing through a straw. It takes far more energy and effort to move air through a clogged filter (if it moves through it at all). Letting an air purifier run with a clogged filter means air in the room is not being cleaned nor is indoor air quality being improved. Electricity is wasted while the air is not getting any cleaner.
Air Filter Lifespan Factors
The filter change schedules found in air purifier owner's manuals are based on estimates. How long an air purifier filter lasts can be affected by a few factors.
Air Purifier Usage
Air purifier run time impacts how long the filter(s) last. Most air purifiers are designed to run constantly, 24 hours a day, 7 days a week. For people with respiratory issues this is the best method to maintain healthy indoor air quality. Running the air purifier for only a few hours a day or during certain activities can extend filter life and reduce electricity usage. Just remember, the more harmful pollutants an air purifier captures, the less chance those same pollutants end up in your lungs.
Filter Construction Matters
Air filter quality and filter type also matter. Poorly made filters may clog sooner leading to poor air purifier performance. It takes careful engineering to create filter media able to capture tiny particles without impeding airflow. They may also fit poorly allowing air to bypass the filter. Poor filter construction can also lead to uneven airflow.
Volatile organic compound (VOC) filter lifespan can depend on what is in the air. These filters are designed to soak up chemicals and smells. Things like air fresheners, scented candles, cooking odors, even chemical off gassing from flooring can saturate a VOC filter to the point of it no longer working.
Pollution Levels
The dirtier the air is outside, the more likely it is to affect indoor air quality. Outdoor air pollution is eventually indoor air pollution eventually. Areas affected by wildfires are especially susceptible to smoke, ash and soot making their way into the home. Wildfire smoke carries extremely fine particles that make their way into almost everywhere. An air purifier is a great way to remove these tiny particles from the air, but the sheer amount can clog a filtration system if the smoke is especially bad.
Environment
The type of things being filtered from the air can have an impact on air purifier filter life. Environmental conditions such as dry, dusty areas can have high levels of particulates in the air that can quickly clog an air filter. Agricultural activity can also stir up dust. Areas around busy roadways and highways are also hotbeds for higher PM2.5 levels. A HEPA filter can catch these tiny particles, but they will also clog up faster due to the denser filter design.
During pollen season it is easy to see the source of our allergies and respiratory issues in the air all around us. Pollen can range in size from 2.5 microns up to 200 microns. When pollen is in overdrive, so is your air purifier.
Determining Filter Change Frequency
How often you change your air purifier filter depends on a few factors. It is worth taking a few minutes to read over the air purifier owner’s manual to get familiar with the different filters.
Here’s is how often filters need to be serviced for a typical air purifier:
- Pre-filter - 6 months
- Main filter - 12 months
- VOC filter - 6 months
Not every part of an air purifier relies on filter media. Some air purifiers rely on ion emission elements (ion generators) that can actually be a source of ozone, which itself is a pollutant. The Intellipure Compact uses DFS air filtration technology and has been third party certified Zero Ozone so you can breathe with confidence.
Follow The Manual
Your air purifier owner’s manual should mention a typical filter replacement frequency. In reality these manufacturer’s guidelines are an educated guess based on a number of factors. The focus is on having an air purifier that removes airborne pollution as efficiently as possible, even if the filters are changed a little early. It is better than the alternative of having an air purifier that isn’t doing its job due to clogged filters.
Listen To The Air Purifier
One common air purifier feature is a filter maintenance notification reminder. When the filter condition has reached the point of needing replacement, a light will turn on or flash letting you know it is time to change the filter. No guessing needed, when the air purifier says it needs maintenance, do it.
Take In The Broader Picture
Environmental conditions outside the home can have an impact on how often you need to change filters. Urban areas and industrial zones tend to have higher concentrations of pollutants. Wildfires can pump large amounts of tiny particles into the air. If outdoor air quality in your area is constantly in the red it is a good indication that your air purifier usage frequency is likely higher to keep your indoor air clean.
These situations signal that air purifier filter changes need to happen more often. The safest method is to cut the recommended filter change frequency in half. For example, if the owner’s manual says to change a filter once a year, change it every 6 months. If your air purifier is equipped with a VOC filter and you notice bad smells creeping in, it is probably time for a change.
Know Your Filters
Depending on the air purifier design there may be a single filter, or multiple filters. Having more than one filter means filter efficiency can be designed to focus on one stage of the air purification process.
Pre-Filter
The job of the pre-filter is to catch big things like hair, pollen, dirt, and fibers before they reach the main filter. Having a pre-filter helps extend the life of the main filter so it can focus on removing the truly tiny things. Some pre-filters can be cleaned and put back into service, so check your owner’s manual. Some air purifiers are equipped with washable filters, while some simply require cleaning with a handheld vacuum attachment. Do NOT wash any filter unless it is clearly directed in the owner’s manual.
VOC Filter
VOC filters that soak up chemicals and smells can be separate or integrated into another filter. Also known as an activated carbon filter it is made up of special materials that bind to chemicals and odors that pass through other filters. Their effectiveness at pollutant removal is thanks to the physical characteristics of processed carbon. If you looked at activated carbon with a microscope it would look like a sponge, full of tiny holes. Those holes create an enormous amount of surface area in comparison to the fine charcoal grains in the filter. To put it in perspective, 1 ounce of activated carbon can have a surface area of 21 acres! All that surface area makes for an amazingly effective VOC removal tool.
Main Filter
The main filter (typically a HEPA filter or equivalent efficiency) removes the tiny particles that make it past the pre-filter. The main filter is where the most air quality improvement is found. This filter is usually a pleated design which increases filter surface area by making the filter thicker without having to make it longer or wider. If you took apart a pleated filter the filter media would look like an accordian. Main filter media can be made from fiberglass, plastic, polyester, even paper. How the filter is designed depends on which material is best for the intended purpose.
There is much discussion about whether or not you can wash a HEPA main filter and the answer is…maybe. Some air purifiers do claim to have a reusable, washable HEPA filter. If that is the case then you must follow the cleaning instructions exactly. In any other case it must be assumed that the HEPA filter is not a washable filter and must be replaced. Washing a filter that isn’t designed to be cleaned damages the filter media and reduces its ability to capture particles. The filter may seem to flow freely after cleaning, but that is only because it isn’t catching anything!
Maintaining routine filter replacement schedules is the key to proper air purifier filter maintenance. While one filter may have a different filter lifespan than another, it is always good to regularly check your air purifier to make sure it is working properly. Since most air purifiers sit quietly doing their job day after day, it is easy to miss when they are not working as they should.
Filter Replacement Signs
Following the filter change schedule in an air purifier’s owner’s manual is one way to follow air purifier maintenance. But there are other signs that it is time to change your air purifier filter.
Built-In Filter Change Indicator
This one is pretty easy and obvious to follow. If your air purifier has a filter change indicator, use it. The built-in indicator takes air purifier usage frequency into account as well as a host of other factors depending on the unit. It is usually a pretty safe bet on when to replace your filters before reduced effectiveness occurs.
Visual Check
A simple visual inspection can quickly identify a clogged filter. If it looks dirty, then it is dirty, simple as that. But there are other things you need to check when looking at your filter. Is there any physical damage to the media (tears, cracks, dents)? Is the filter seal still intact? If you see gaps around the filter then air is likely bypassing the filter media and not being cleaned. In extreme cases a filter may actually collapse leading to unusual noises (like the fan hitting the filter). If the filter is compromised in any way it should be replaced.
Bad Smells
If your air purifier is equipped with a VOC filter then it should be keeping unpleasant odors away. VOC filters have a limit to the amount of odors and chemicals they can remove from the air before the media is saturated. The VOC filter itself may not experience decreased airflow, but it won’t be removing VOCs as intended. If things smell when they didn’t before, it is time to change the VOC filter.
Dirty Air
If your allergy symptoms start flaring up but you’ve been running your air purifier constantly, the filter may be due for a change. Just because an air purifier is running doesn't always mean it is cleaning the air. Most purifiers will continue to turn the fan even if airflow through the filter is completely clogged.
Air Purifier Maintenance Tips
The best way to maintain your air purifier is to follow the manufacturer’s guidelines found in the owner’s manual. Make sure to keep up with regular cleaning of the air purifier to remove any dust bunnies, leaves, or other large debris that might clog the air intake. Air purifier filters are made to exact filtration specs so only use the filter that is specified for your machine. Understand that filter lifespan can change depending on the volume of pollutants or allergens in the air. Don’t feel bad about changing filters early, think of them as disposable allergen traps that protect your health. If you follow proper maintenance and optimal usage practices your air purifier will be your health partner for years to come.
Changing air filters is simple, so it's easy to protect your investment and your health at the same time.
