How clean is your home’s air? You may be surprised to learn that sweeping and vacuuming regularly won’t result in a dust-free home. In fact, the average home racks up as much as 40 lbs. of dust each year from animal dander, dead skin cells and other debris. Gross, right? That’s why many people invest in HEPA air filters for air purification.
THE BASICS: WHAT ARE HEPA FILTERS?
High-efficiency particulate air filters, commonly called HEPA filters, trap tiny particles of dust and debris. All filters are designed to do this, but HEPA filters have tightly woven mesh that captures 99.97 percent or more of airborne particles with a diameter of at least 0.3 micrometers. This makes HEPA filters a practical choice for a number of functions, including capturing allergens and blocking the circulation of toxins.
HEPA filters may seem like a recent trend, but they’ve actually been around since the 1940s. They were originally invented to prevent radioactive particles from spreading. Over time, HEPA filters have evolved for use in homes, schools, medical facilities and warehouses.
Not all filters are HEPA filters. You can identify HEPA filters by reading their packaging and checking if the filters have an accordion-like design. The accordion-style folds trap dust rather than simply capturing it. This helps create fresh, clean air for people and pets.
TYPES OF HEPA FILTERS
HEPA filters are available for business and home use. There are six different types: A, B, C, D, E and F.
Testing shows that D and F filters typically capture the most debris. These filters trap up to 99.999 percent of dust particles, with D capturing particles 0.3 micrometers or large and F capturing particles as small as 0.1 micrometers. C filters capture up to 99.99 percent of particles measuring at least 0.3 micrometers. A, B and E filters are slightly less effective, capturing 99.97 percent of particles that measure at least 0.3 micrometers.
HEPA filters come in different sizes and shapes depending on their purpose. Vacuum cleaners often have small HEPA filters shaped like rectangles or squares. Furnaces have large HEPA filters, but the biggest filters are found in airplanes and motor vehicles. When you get your car’s oil changed, the mechanic may ask if you want a HEPA filter. He’s referring to the air filter under your hood that prevents debris from damaging your engine.
HOW DO HEPA FILTERS WORK?
When you install a HEPA filter in an appliance, it often uses a combination of three particle-capturing mechanisms: interception, impaction and diffusion.
- If you’re a sports fan, picture HEPA interception as a football interception. Medium-sized dust particles follow the flow of air through a filter and are grabbed by a fiber as they pass by.
- Impaction occurs when larger particles are too heavy to follow the air flow through a filter and instead collide with a fiber and become trapped.
- Diffusion works on the smaller particles. They move erratically through the air flow eventually coming in contact with a fiber.
Particle movement is generally blocked by interception or impaction.
The accordion-inspired design of HEPA filters helps trap dust and allergens. Traditional filters have loose weaving that allows for ample airflow. HEPA filters have tightly woven fibers and folds that trap tiny particles. These tiny particles generally sneak through traditional filters and end up recirculating through the air.
WHAT ARE THE BENEFITS OF HEPA FILTERS?
HEPA filters capture microscopic particles that pollute the air in your home, office or vehicle. Traditional filters also capture debris, but they aren’t as effective as HEPA filters. They don’t capture as many microscopic particles as HEPA filters, which means you’re still breathing in tiny particles that can make you sick.
HEPA filters help block the circulation of dust mites, dead skin cells, pet dander, dirt, indoor and outdoor allergens, mold spores and bacteria. They may enhance the health of people with various medical conditions and diseases, including:
- Chronic bronchitis
- Reactive airway disease
- Environmental allergies
- Cystic fibrosis
- Chronic obstructive pulmonary disease (COPD)
HEPA filters are also a popular option in warehouses and medical facilities due to their dependable performance. When installed correctly, a HEPA filter helps block the flow of hazardous particles and infectious viruses. This is important in facilities where workers or patients may come in contact with disease-causing particles.
Parents often use HEPA filters to protect their family from harmful particles in the home. HEPA filters are also useful for pet owners, especially if their pets shed often or track in excessive amounts of dirt and pollen.
WHAT ARE THE DISADVANTAGES OF HEPA FILTERS?
While HEPA filters have numerous advantages, there are a couple minor disadvantages. HEPA filters do not filter some gasses, including chemical vapors and cigarette smoke. These filters also fail to neutralize odors, so your home or business may still smell unpleasant even after many of the particles are removed.
However, you can tackle this potential problem by using a second filter with your HEPA filter. Choose a filter made from activated charcoal if odor absorption is a priority.
You can also use a HEPA filter with a prefilter. A prefilter goes in front of a HEPA filter and can capture large particles, such as hair or chunks of dirt. Smaller particles pass through the prefilter and become lodged in the HEPA filter.
It’s also worth noting that HEPA filters are fragile. It’s easy to break or damage a HEPA filter if you drop it or insert it into your appliance too roughly. HEPA filters may also come with higher price tags than other types of filters, though the benefits arguably outweigh the extra cost. You may even save money on medical expenses if your HEPA filter captures particles that trigger asthma attacks or allergic reactions.
CHOOSING THE RIGHT HEPA FILTER FOR YOUR NEEDS
When shopping for a HEPA filter, consider your budget, health and personal preferences. Keep in mind HEPA filters are not permanent; you must change them at least once a year, sometimes as often as once a month. It’s also important to install HEPA filters correctly or find someone who can. A poorly installed HEPA filter does not effectively capture microscopic particles.
The United States Department of Energy requires HEPA filters to meet strict guidelines before receiving HEPA classification. Watch out for brands that attempt to pass off knockoff filters as authentic HEPA filters. Clues include terms such as “HEPA-like” or “HEPA-style” on the packing. Air filters with these terms are not authentic HEPA filters even though they mimic the style and design of HEPA products.
Many homeowners install HEPA filters in their furnaces so they can trap unwanted particles. If you have allergies or a respiratory condition, you may also want to use HEPA filters in your vacuum and air purifying systems. Keep in mind that HEPA filters capture particles, but they do not kill live microbes. You may want to combine your HEPA filter with an antimicrobial layer of protection.
- HEPA filters typically capture particles as small as 0.3 micrometers, though some HEPA filters block debris as small as 0.1 micrometers.
- These filters help protect the health of kids, adults and pets.
- You can install HEPA filters in your furnace or vacuum, but filters are also available for motor vehicles and air purifiers.
- Prices for HEPA filters are often higher than traditional filters, but the benefits may outweigh the additional cost.
If you decide to purchase a HEPA filter, install it carefully and be prepared to change it according to the manufacturer’s recommended schedule. This helps prolong the life of your filter so you receive the maximum benefits of its filtration-friendly design.