An estimated 84% of Americans struggle with indoor allergies caused by breathing in dust mites, pet dander, mold, and other allergens in their homes. But there is some good news for these allergy sufferers. Air purifiers and other devices equipped with HEPA filters can dramatically lower exposure to these allergens.
What Is a HEPA Filter?
HEPA filters are filters consisting of thin fiberglass or synthetic polymers and activated carbon materials. They are not the same as standard air filters, which are filters made up of cotton paper sheets or polyester.
The fiberglass or synthetic polymers and activated carbon-based materials in HEPA filters can trap up to 99.97% of airborne particles as small as 0.3 microns. Standard air filters, meanwhile, capture less than 20% of particles between 3.0 and 10.0 microns.
How Do HEPA Filters Work?
HEPA filters work in concert with the fans built into HVAC systems, air purifiers, and vacuums. The fan helps push air through the thin fiberglass or synthetic polymer filters, removing harmful particles that would otherwise remain in the air. This process happens in three phases: inertial impaction, interception, and diffusion.
All of these help remove the following from the air:
- Bacteria
- Dust mites
- Microorganisms
- Mold spores
- Pet dander
- Pollen
- Smoke
- Viruses
To appreciate what makes HEPA filters superior filters, we need to know more about inertial impaction, interception, and diffusion:
- Inertial impaction – This trapping mechanism captures larger particles that are moving too fast to follow the air stream as it curves around filter fibers. As air bends around the fibers, heavier, larger particles continue on a straight path and eventually get sucked into the fibers in HEPA filters. Inertial impaction primarily removes particles larger than 1.0 microns from the air.
- Interception – This trapping mechanism captures mid-sized particles light enough to follow the air stream as they weave through the HEPA filter network. These are particles that are between 0.1 and 1 microns.
- Diffusion – This trapping mechanism utilizes Brownian motion, the random, erratic movement of particles caused by collisions with fluid molecules, to capture microscopic viruses measuring 0.02 to 0.3 microns that might be circulating in a home’s indoor air.
How Long Do HEPA Filters Last?
Generally speaking, HEPA filters last 6 to 12 months in standard portable air purifiers and vacuums and 1 to 3 years for whole-home HEPA filters. It is worth noting that several things can increase or decrease the lifespan of these complex filters.
How To Extend the Life of Your HEPA Filter
Extending the life of HEPA filters can be achieved with regular maintenance, pre-filter cleaning, ensuring proper airflow, and controlling indoor humidity. For homes with pets, creating pet-free zones can prevent pet dander from clogging HEPA filters in portable air purifiers and vacuums too quickly.
In whole-home HEPA filter systems, checking for and resolving duct leaks can also extend the life of HEPA filters. The same applies to keeping windows closed while operating HEPA-equipped devices.
How Prolonged Usage Affects the Life of a HEPA Filter
The longer devices equipped with HEPA filters run, the more dust, pollen, viruses, and other contaminants those filters can capture, which is great for improving indoor air quality but not so great when it comes to filter life. That’s because prolonged usage causes these advanced, high-tech filters to reach their saturation point much faster.
Signs That Suggest It Might Be Time To Replace Your HEPA Filter
Several signs will present themselves when HEPA filters are no longer working as effectively or efficiently as they once did. At that point, it is best to replace them.
Some of the more notable of these signs include the following:
- Noticeably reduced airflow
- Musty or stale odors
- Increased dust accumulation
- The resumption or worsening of allergy symptoms
- Visibly discolored or clogged filters
- If so equipped, a glowing filter change indicator light
Can HEPA Filters Be Cleaned?
While there are exceptions depending on the manufacturer, most true HEPA filters are not water washable. Most, however, can be vacuumed to remove dust and debris buildup. Washing HEPA filters with water can destroy the tight, intricately woven glass fibers that make them so effective at capturing airborne contaminants.
When Should You Upgrade to a Whole-Home HEPA System?
Whole-home HEPA systems can filter air throughout an entire home, ensuring consistent air quality in every room. They are also better at neutralizing volatile organic compounds (VOCs) and household odors than portable systems.
Bearing that in mind, such systems are a good fit for homes that experience extreme VOC off-gassing or dust accumulation and for homeowners and occupants who suffer from severe allergy or asthma symptoms.
Frequently Asked Questions
Do HEPA Filters Lose Effectiveness Over Time?
As they age and continue to trap airborne contaminants, airflow in HEPA filters can become restricted. And that can make them less effective in terms of improving or maintaining good air quality in a home.
How Do I Know If My HEPA Filter Is Clogged?
HEPA filters become discolored and work less effectively when they become clogged.
Are HEPA Filters Worth It for Home Use?
Because they can remove nearly 100% of airborne contaminants that cause dust buildup and trigger allergy symptoms, HEPA filters are absolutely worth it for home use.
Can a HEPA Filter Damage an HVAC System?
While rare, it is possible for a HEPA filter to damage an HVAC system if the motor in that system is not strong enough to push air through the dense material in the HEPA filter.
Hire a Pensacola HVAC Technician Today
HEPA filters do a remarkable job of purifying air and reducing dust buildup in a home, both of which help keep allergy symptoms at bay. But to achieve these results long-term, you must replace them periodically.
To learn more about HEPA filters, including whether or not a whole-home indoor air quality system is right for you, consider speaking with a Pensacola One Hour Air Conditioning & Heating expert today.