The Ultimate Guide to HEPA Air Filters: What To Know

If you want to know how HEPA air purifiers can improve your health and the quality of your indoor air, you’ve come to the right place. There’s a great deal of information about air purification systems with various gimmicks, but to clean your air reliably, it’s best to stick to scientific data. An air purifier fitted with a HEPA filter is an empirically proven method to reduce air pollution indoors.

What do you need to know about HEPA air filters as you shop for purifiers? With this ultimate guide from Smarter HEPA, you’ll have the information you need to choose the ideal air purifier for your unique needs.

What Is a HEPA Filter and How Does It Work?

HEPA is an acronym for High-Efficiency Particulate Air; a HEPA filter is remarkably adept at pulling particles of various sizes out of the air. Early HEPA filters originated in the 1940s, and to this day, their construction is not particularly elaborate. They are generally made of either glass or synthetic fibers aligned randomly to catch particulate matter.

A high-quality HEPA filter can pull particles like smoke, pollen, viruses, bacteria, and PM2.5 particulate matter out of the air. These particles often vary in size, and HEPA filters are desirable for air purification because they can catch multiple particle sizes simultaneously. How do they do it?

10 Microns or Larger: An Easy Catch

By HEPA filter standards, a particle at least 10 microns in diameter is pretty big and easily caught by the random arrangement of fibers that comprise the filter. Smoke particles are often fairly large, so a HEPA filter will catch the vast majority of them in the first pass.

0.3-1 Microns: A Tricky Size

Particles that fit into this category often include microscopic bacteria. They’re small enough to squeeze between gaps in the filter fibers, but their weight brings them down. The HEPA filter intercepts these particles because they don’t move quickly enough to evade those randomly arranged fibers.

Less Than 0.3 Microns: What Is Brownian Motion?

The smallest pollutant particles in your indoor air may seem like they’d pass right through your HEPA filter. However, particles that small don’t travel in a straight line. In a phenomenon called Brownian motion, they bounce around haphazardly when they come into contact with gas molecules.

Thanks to Brownian motion, HEPA filters can easily capture these tiny particles. As they bounce around like microscopic pinballs, they get trapped in the filter fibers, so you won’t breathe them in.

HEPA vs. Non-HEPA Filters

While HEPA filters are one of the best investments you can make for your respiratory health, they’re far from the only air filters out there.

MERV Filters

The HVAC system in your home is likely fitted with air filters that follow the Minimum Efficiency Reporting Value (MERV) rating system. The MERV scale ranges from 1 to 20, categorized by the percentage of pollutant particles the filter can grab in a single pass.

HEPA filters are similar to MERV filters, but they adhere to a much higher standard for removing particles. For example, an H13 HEPA filter is similar in effectiveness to a MERV 17 filter. As you shop for HEPA air purifiers, you’ll notice a numeric rating with an H in front of it. Here’s what the most common ratings mean:

• H11: Removes 95 percent of particles larger than 0.3 microns in one pass.
• H12: Removes 99.5 percent of particles larger than 0.3 microns in one pass.
• H13: Removes 99.97 percent of particles larger than 0.3 microns in one pass.

Carbon Filters

Many highly efficient air purifiers use both a HEPA filter and a carbon filter because they target different pollutants in the air. While HEPA filters focus on removing particulate matter, carbon filters adsorb dangerous gases and volatile organic compounds (VOCs) out of your indoor air.

For highly efficient air purification, especially in areas with lots of air pollution, use an air purifier fitted with both a HEPA filter and a carbon filter.

Why Use a HEPA Air Purifier?

You’ve probably gathered by now that running a HEPA air purifier in your home is good for your health. Which specific benefits can you expect with high-quality air purification?

Improved Cognition

Harvard University performed a study on office workers in six countries that found a correlation between high PM2.5 levels and reduced cognitive function, including slowed response times. Because a HEPA air purifier removes more than 99 percent of PM2.5, using one in your home can improve brain function overall.

Asthma and Allergy Relief

If you or any members of your household suffer from allergies or asthma, an air purifier with a HEPA filter will reduce the severity of those symptoms. The Journal of Allergy and Clinical Immunology published a double-blind study on the effects of air purification on individuals with allergies. Their results demonstrated significant relief from symptoms after just a few weeks of HEPA air purification.

Reduction of Diabetes Risk

Scientific research in recent years has uncovered a significant link between PM2.5 air pollution and the risk of developing diabetes in adulthood. A study on the Danish Nurse Cohort found that individuals who live in more polluted areas are more likely to develop diabetes. However, with a HEPA air purifier, you can get your indoor PM2.5 levels under control and reduce your diabetes risk.

When To Replace Your HEPA Filter

For your air purifier to work correctly, the HEPA filter should be clean and in good condition, with no holes or tears. How can you tell when you need a replacement HEPA air filter for your purifier?

Read Your Manual

When you purchase your air purifier, hang on to the user manual, as it has plenty of information specific to your purifier’s make and model. There is no one-size-fits-all guideline for replacing your filter, as that timeline depends on where you use the purifier and how much pollution it’s filtering out. However, the information in the user manual will provide a useful starting point.

Use a Calculating Tool

Smarter HEPA carries a variety of air purifiers manufactured by Smart Air, like the Sqair and the Blast Mini. If you’re using a Smart Air purifier, enter all relevant information into this calculating tool for more tailored advice on when to replace the HEPA filter.

If you’re unfamiliar with the technology of HEPA air filters, this ultimate guide provides what you need to know before you purchase an air purifier. Choose purifiers and replacement filters based on your unique circumstances, like air pollution levels and health concerns. Air purification with HEPA filters can significantly improve your quality of life, so don’t put it off any longer!