High-Efficiency Particulate Air filters, abbreviated to HEPA, are a bit of a mystery to homeowners. Most get that these filters offer superior filtration, but other than that, you may not how they work. There is a bit of confusion on the subject online. As your Canadian HVAC experts, we are here to clear up your misconceptions, so you know exactly what filter you need for your equipment.
What Is a HEPA Filter?
HEPA filters are the gold standard for air purification. They are used everywhere from dirty construction sites to hospitals to keep the air safe and clean. They are designed to capture at least 99.97% of airborne particles down to 0.3 microns, which is the most penetrating particle size. They rely on dense mechanical fiber designs rather than harmful chemicals to trap microscopic irritants like dust, pollen, mold, and bacteria.
How HEPA Filters Improve Home Indoor Air Quality
In order to be a true HEPA filter, a filter needs to catch 99.97% of particulates in the air at 0.3 microns in size. HEPA filters are often installed in air purifiers, which not only use a HEPA filter to remove particles from the air but may also use other types of filters to offer better performance.
Many air purifier systems include features such as:
- A pre-filter to catch larger dust, hair and debris
- Activated carbon to help reduce some odours
- HEPA filtration for fine particles such as pollen, mould spores, dust and smoke particles
- Optional UV light in some systems
HEPA filters are too restrictive to be installed directly in line with the furnace, so they are usually installed with a bypass. Some HEPA filters mount directly to the exterior of the ductwork and have their own internal bypass.
You should always get your HVAC professional’s advice to be sure that you have a true HEPA filter and that it is compatible with your home’s HVAC setup.
Are HEPA Filters Necessary for Homes?
HEPA filters are designed to remove very small airborne particles, not to protect your furnace or air conditioner. For that reason, you still want to have a good quality furnace filter installed in the main airflow of your HVAC system to remove dust, dander and other larger particles.
We think MERV 10 to 13 is often the sweet spot for many homes, but this depends on your specific equipment. A good quality main system filter will reduce how often you need to replace the more expensive HEPA filter.
If you are concerned about cost, you can use a HEPA filter when it matters most to you, such as during allergy season, wildfire smoke events or periods when indoor air quality is a bigger concern. For the rest of the year, a high-quality main system filter may be enough.
Why Use a HEPA Filter?
HEPA filters will improve your indoor air quality by removing many of the smallest particulates in the air. Cleaner air may help reduce exposure to allergens, dust, fine particles, mould spores, pet dander and some smoke particles.
For homeowners with allergies, asthma or sensitivity to poor indoor air quality, this can make a noticeable difference. It is not a cure-all, and it does not replace ventilation, humidity control or regular HVAC maintenance, but it can be an important part of a healthier indoor air strategy.
When Should You Change Your HEPA Filter?
If you are using a HEPA filter, you should not change it only on some preset schedule. You should follow the manufacturer’s instructions and check the condition of the filter.
The HEPA filter itself may last an entire year, but this depends on your system, your home and how often the unit runs. You’ll know it’s time to change your filter when you can no longer see light through it, airflow is reduced, or the manufacturer’s replacement indicator says it is due.
FAQ: HEPA Filters and Indoor Air Quality
Do HEPA Filters Help With Wildfire Smoke?
Yes, HEPA filters can help reduce fine particles from wildfire smoke inside the home. During smoke events, many homeowners use portable HEPA air cleaners in key rooms or whole-home filtration strategies where appropriate.
Can I Put a HEPA Filter in My Furnace?
Usually, no. A true HEPA filter is often too restrictive for standard furnace airflow. Installing the wrong filter can reduce airflow and strain the system. Whole-home HEPA filtration is typically installed as a bypass system or separate air cleaning unit.
Is a HEPA Filter Better Than a Regular Furnace Filter?
It depends on the job. A furnace filter protects your HVAC equipment and captures larger particles in the main airflow. A HEPA filter is designed for much finer particle filtration. Many homes benefit from using both, as long as the system is designed properly.
Improve Your Indoor Air Quality with ClimateCare
Increasing your indoor air quality and your comfort is our specialty. For more information about HEPA filters and how they can help your family, contact your local ClimateCare today.
