When you’re shopping for an air purifier, you’ll probably come across the word “HEPA.” It’s touted as the ultimate solution to air filtration problems, but what does it mean? How do HEPA filters help consumers, what do they do, and what are the drawbacks?
Choosing the right air filter technology can be a matter of life and death for those with severe allergies and respiratory conditions. Knowing what’s in your air purifier or HVAC is crucial. Many different devices use HEPA filters, but the filter always performs the same essential function. Not all HEPA products are created equal, and some offer additional benefits and superior filtration. You need to look at more than just the filter in order to make an educated purchase, but it’s an important place to start. We’ve put together a guide to help you better understand HEPA products, their uses, and how they fit into the bigger picture of air filtration.
What Does HEPA Mean?
The letters of HEPA stand for High-Efficiency Particulate Arrestance. HEPA filters are not a brand, and the name covers a range of different filtration products from various manufacturers. Think of HEPA as a title rather than a name. Whenever a product has HEPA certification in the title, it’s proof that the filter meets regulated air filtration standards. The Institute of Environmental Sciences and Technology controls the standards for HEPA filters, and only products that meet exacting criteria get to call themselves certified HEPA products. To qualify for certification, a filter must remove 99.97 percent of airborne particles with a diameter of .3 microns or larger.
The best products exceed these standards, but this the bottom threshold for HEPA labeling ensures reasonable quality and performance. Since it’s difficult to tell how many particles a filter actually captures, HEPA gives consumers a reliable standard to judge products by. While you shouldn’t judge a product purely by the fact that it contains a HEPA filter, this does give you a place to start.
HEPA filters physically trap particles. Filtration technology is fairly diverse, and includes everything from ionization to carbon in order to catch allergens, odors, car emissions, and anything else that passes through. Multi-stage filtration tends to work the best, because each of these processes targets particles in different ways, but HEPA filters all use the same principle technology. Tightly packed fibers make a web to trap particles within the filter itself. They physically catch passing particles, and when they’re dirty, they have to be replaced.
What Is the Advantage of HEPA Filtration?
The primary advantage of looking for HEPA filters in air purifiers and other products is the ease of recognition. The letters are difficult to miss. Certified HEPA filters will always remove 99.97 percent of particles .3 microns or larger. It’s similar to FDA approval. You know it meets basic standards.
The physical design of HEPA filters is also a classic filtration technology. As manufacturing processes grow more advanced, the tried and true methods improve. Webs are tighter, and new materials attract and capture more particles. Forcing air through a HEPA style filter is still the most efficient way to clean particles from the air.
What Are the Disadvantages?
Although it’s easy to see that a product meets basic standards through HEPA labeling, that doesn’t mean it’s necessarily a good product. Some companies squeak by the regulations and use an average filter in a poor product. It’s easy to see the HEPA label and assume you’re getting a quality product when you’re actually getting something else. Some products also use HEPA type filters. These work in the same way as a certified HEPA filter, but have not been tested. Unfortunately, some manufacturers take advantage of how easy it is to confuse these terms. This is why thorough research and product reviews are important for consumers.
Apart from these issues, however, there are fairly few problems with the system, and HEPA technology has more advantages than disadvantages. Technological advances necessitate changing standards, though. The existing HEPA requirements are not particularly rare or advanced, and in order for HEPA to maintain its relevance, new standards should be applied in the next few years.
Where Are HEPA Filters Used?
Home Air Purifiers
Air purifiers are the most obvious product to use HEPA filtration. They make life easier for consumers with upper respiratory conditions, allergies, and persistent home odors. Many people choose to use air purifiers not just to relieve existing symptoms, however, but to generate cleaner, better smelling air. HEPA filtration only traps a limited amount of, since odors are carried by particles but for the most part are smaller than .3 microns. Look for a HEPA filter that works alongside an activated carbon filter to remove stubborn odor.
Vacuum cleaners collect dirt through suction, and the suction process requires the machine to send the air it pulls in back into the environment. Top of the line vacuum cleaners use HEPA filters to keep collected dirt and dust inside the machine. By keeping the tiny particles inside rather than letting them enter the recirculation process, vacuums act as a temporary air purifier. Vacuums with HEPA filters leave rooms cleaner, from the carpets you walk onto the air you breathe.
Home HVAC systems
Home HVAC systems are filtration systems that go into a home’s existing air conditioning and heating systems. Ventilation systems cycle air through the entire home, adding HEPA to HVAC turns the entire system into a massive air purifier. While it isn’t as efficient as a freestanding air purifier for an individual room, it does process a greater volume of air and improves air quality in the entire house. The HEPA filter plays the same role in an HVAC that it does in a free standing air purifier. The only drawback is that HVAC systems require stronger fans than regular ventilation systems because the system is forcing the air through the filter, and not just empty vents.
Automotive and Aerospace
Cars cycle air through an air conditioner and heater. Specialized HEPA filters fit into many cars’ filtration systems, which then gives the occupants fresh, filtered air whenever they drive. Since highways are full of toxic car emissions, car filters help many users breathe easier during long commutes. HEPA filters also help scrub the air passengers breathe on almost every commercial aircraft.
Are Some HEPA Filters Better than Others?
The short answer to this question is: yes. We talked about this briefly in the sections above, but there are many different HEPA filters from many different manufacturers. They use different web patterns to most efficiently trap particles, advanced materials that attract irritants, and even different shapes to maximize filtration time.
Blueair pairs ionization with a HEPA grade filter, which charges the particles so they are attracted to the filter’s material. IQAir units trap particles as small as .003 microns. And, that is literally a hundred times more effective than the basic HEPA regulations require. RabbitAir, which markets heavily to families with children, uses materials they claim sanitize the particles captured in the filter. Alen also makes top notch purifiers that combine odor fighting features with an awesome HEPA filter. A HEPA filter can cater to more needs than you realize, and finding your ideal filter requires some very careful research. As a general rule, however, the best HEPA filters come from companies like those listed above, who expand on the basic principles and requirements of HEPA regulations. In this purifier range we also recommend that you look beyond CADR claims and focus on finding a quality product.
What to Consider Beyond the HEPA Filter
A great filter doesn’t always equal a wonderful product. Even if you’ve found an air purifier or vacuum with a high quality filter, you need to do some more investigation. The filter’s housing is very important, as is the machine that surrounds it. You can have the best HEPA filter on the market, but if the supporting product is shoddy, look elsewhere.
Filters rely on fans in order to work. It takes more pressure to force air through the filter than empty space. If air can find an alternate route, it will take it. A slight gap or crack around the filter renders strong fans and good filters are useless. If the filter is not properly sealed, the majority of the air will go around rather than through the filter. It takes exacting construction standards to seal a replaceable filter into a product. Cheap products often fail to thoroughly seal the path between the fan and the filter, which ruins the entire process.
As great as HEPA filters are, they function best as part of a team. The best air purifiers use anywhere from three to five different filtration steps. By filtering out large particles before they can reach the HEPA filter, you increase the filter’s lifespan. HEPA filters are meant to catch small particles, so multi-stage filtration allows them to function at peak capacity.
HEPA certification is a standard, but it’s a pretty basic standard. It gives consumers a place to start when analyzing a potential purchase. Unfortunately, many products with HEPA filters are relatively ineffective, and consumers need to review the product’s full list of features in addition to customer sentiment before committing.
Although many products use HEPA filtration, few need to live up to the same standards as air purifiers. While clean air is important wherever you go, many air purifier owner’s need extremely clean air in order to live normal lives. HEPA labeling may be enough to let you know a car’s air filter will work well, but air purifiers require more attention and multiple stages of filtration. HEPA is only one of those steps, even if it is the most thorough.