The Breathe Easy Blog

HEPA Filter Sales carries true HEPA filtration and genuine ductless mini split filters, and they are not the same thing. Here’s what each filter is, why mini splits don’t use HEPA media, and why “washable” doesn’t mean “permanent” — with sources from the EPA, the Department of Energy, and the manufacturers themselves.

Your central furnace and air conditioning filter does more than keep dust out of the equipment, but only if you choose and change it correctly. Here's what standard filters actually do, how MERV and HEPA ratings compare, and when a central air purifier is the better upgrade for cleaner indoor air at home or work. The Basics of Air Filters A standard HVAC filter's main job is to protect the equipment, not the people in the building. That surprises most people. The thin 1-inch filters sold at big-box stores are often called "boulder catchers." They stop large dust and debris from reaching the blower and coil, but they let most fine particles pass through. If you can see through a filter, it isn't catching the particles you can't see, such as fine dust, mold spores and bacteria. What Should Homeowners and Businesses Do? In a word: upgrade, carefully. If you already use upgraded filters, follow the recommended replacement schedule and adjust for your environment. Living near a busy road, wall-to-wall carpet, pets, active kids and nearby woods all mean changing filters more often. Carpet in particular holds fine dust that gets stirred back into the air every time someone walks across it. Understanding MERV Ratings Most central system filters carry a MERV (Minimum Efficiency Reporting Value) rating from 1 to 16, which describes how well the filter captures particles of different sizes. Higher MERV filters capture more fine particles, but they also restrict more airflow. See the EPA's guide to MERV ratings for the details. That airflow restriction is the catch. A filter that's too restrictive for your system can reduce efficiency, raise operating costs and strain equipment, and many residential duct systems are undersized to begin with. Check what MERV rating your system is designed to handle before upgrading. Ductless mini splits work differently. Their filters are rarely MERV-rated. The main screens are cleaned every few weeks, and many units offer specialty filters to capture fine particles and reduce odors. See our mini split filter buying guide. What Is a HEPA Filter? HEPA stands for High-Efficiency Particulate Air. A true HEPA filter captures at least 99.97% of particles 0.3 microns in size, the size that is hardest to filter, and it captures larger and smaller particles even more efficiently. That includes dust, pollen, mold spores and bacteria. HEPA filters are made from a dense mat of fine glass fibers that traps particles as air passes through. The technology dates back to the 1940s, when it was developed to capture radioactive particles during the Manhattan Project. Because HEPA media is so dense, it's far too restrictive to use as a standard furnace filter. That's where portable air scrubbers and central air purifiers come in. Why Air Filtration Matters Indoors When people talk, cough or breathe, they release particles into the air. Large droplets fall quickly, but smaller aerosols can stay airborne for extended periods until ventilation removes them or a filter captures them. Good filtration, together with outdoor air ventilation, reduces the amount of airborne particles people breathe, which is why health and building guidelines recommend both. A Central Air Purifier May Be the Better Answer Instead of forcing a restrictive filter into your furnace, a bypass central air purifier (CAP) connects to your existing ductwork and cleans a portion of the system's airflow through true HEPA filtration, without choking the main system. It works alongside a moderately upgraded furnace filter, and over time all the air in the home passes through it. A CAP uses layered filtration: prefilters catch larger particles first, which extends the life of the HEPA core, often two to three years. Shop Abatement Technologies Central Air Purifiers. Cleaner Air in Commercial Buildings Commercial HVAC systems also filter air before it moves through the building, and they're usually easier to upgrade because most have filter racks that accept thicker, higher-efficiency filters. Unlike most homes, commercial buildings are required to bring in outdoor air to dilute carbon dioxide and other indoor pollutants. That outdoor air carries its own dust and pollen, which makes regular filter changes and maintenance even more important. Need Help Choosing a Filter? Whether it's a furnace filter, a ductless filter or a HEPA air purifier, we'll help you find the right fit for your system. Contact us with your system's model number.

A brief guide from HEPA Filter Sales on how to navigate air filter ratings on filters such as MERV 13 filters for your business to reopen after COVID 19 restrictions.

If you own a Mitsubishi MSZ-FX or MSZ-FW mini split, the part numbers in your owner's manual may not match the filters your unit actually uses. Here's what each filter is, which ones are in stock now, and what to do about the ones that aren't.

Your Abatement Technologies air scrubber is only as effective as the filter inside it. Before you reach for a cheaper “compatible” replacement, here’s what’s actually at stake — for your equipment, your projects, and the air you’re certifying as clean.

After wildfires, hazardous air lingers indoors, posing serious health risks. Many homeowners and businesses mistakenly turn to Negative Air Machines (NAMs), which pull in outdoor air—bringing in more contamination. Instead, the PRED750 Portable HEPA Air Scrubber offers the best solution, filtering and recirculating indoor air to remove fine particulates, harmful gases, and lingering smoke odors. With True HEPA filtration, optional activated carbon filters, and positive pressure capabilities, the PRED750 is ideal for post-fire air quality remediation. Maintain clean air long-term with replacement filter bundles. Learn more at HEPAFilterSales.com.

Choosing the right Fujitsu Healthy Air Filter can be confusing. FA16, FC03, and FA13 filters look similar but are not interchangeable. This guide breaks down the differences, explains how to avoid look-alikes, and helps you get the correct OEM filter the first time.

Have you checked your air filter in the last 90 days? We’re launching the Dirtiest Filter Contest—a fun, community-driven campaign inviting homeowners, businesses, and facility managers to submit photos or videos of their dirty air filters for a chance to win prizes and be featured in our 2026 content. Every system type qualifies. Learn why filter maintenance matters, how to enter, and how your “gross” filter might actually win you something useful.

Installing a DIY mini split can look easy, but hidden installation pitfalls, restricted warranties, and hard-to-source replacement parts often undermine the savings. From improper line-set coiling to manufacturer service limitations, here’s what homeowners should know before choosing a self-install system or buying a professional unit online.