Air Filters Buying Guide Determine which replacement air filter fits your HVAC system and improves air quality High-efficiency air filters are a cost-effective way to help improve indoor air quality, which may be beneficial to family members sensitive to allergens and other particles in the air. This guide will help you understand The Home Depot’s Air Filter Performance Rating system so you can easily choose the air filter that best fits your needs. Tip: Air filters help keep your furnace’s coils and heat exchangers clean, which may prolong furnace life and keep it running efficiently. SHOP ALL AIR FILTERS The Home Depot Air Filter Performance Rating (FPR) System The Home Depot Air Filter FPR ranks all brands of filters we sell by measuring their ability to capture large and small particles, and weight gain over the filter’s lifetime. The Home Depot Air Filter Performance Rating System creates a weighted average for each filter, which is then ranked on a 1-10 scale: 1 being the lowest performance, and 10 being the highest performance air filter.

Filters are rated using the following weighted scale: Large Particle Capture: 60 percent Small Particle Capture: 30 percent Weight Gain/Lifetime: 10 percent • Large particles like household dust, lint, dust mites, pollen and pet dander• Small particles like bacteria and mold spores• Smoke, smog, microscopic allergens plus particles that can carry viruses• Particles that carry odors • Large particles like household dust, lint, dust mites, pollen and pet dander• Small particles like bacteria and mold spores• Smoke, smog, microscopic allergens plus particles that can carry viruses • Large particles like household dust, lint, dust mites, pollen and pet dander• Small particles like bacteria and mold spores • Large particles like household dust, lint, dust mites, pollen and pet dander Common Airborne ContaminantsCommon Airborne Contaminants Filtered by Premium (10), Best (8), Better (6) and Good (4) filters Filtered by Premium (10), Best (8), Better (6) filters

Filtered by Premium (10) and Best (8) filters Electrostatically charged filters provide the highest level of filtration for small particles Fiberglass, polyester, washable, pleated and electrostatic filters each offer different air filtering capabilities. Tip: While most filters are disposable, some may be cleaned with water or by vacuum. An advantage of disposable filters is you’re not exposed to the trapped contaminants during cleaning.used central ac units prices Good for capturing large particles like lint and dustdifferent brands of ac units Can be cleaned and reusedtypes of ac units available Require replacement only every few years Protect furnace motor and trap larger particles Larger surface area captures more particles

Disposable or reusable options Charged fibers help to capture small and large particle Filters are sized in two ways: nominal and actual. Nominal is the approximate size of the filter, rounded up to the nearest inch. Actual is the filter’s exact size. Air filters vary by thickness. They can be less than 1-inch thick, or up to 6-inches thick. The filter should fit snugly in the chamber; loose filters may let air pass around the filter instead of through it. Make sure your filter is sturdy. The frame should be strong enough to withstand pressure caused by the air that moves through it. Check the frame after installation to see if it is intact and that the joints are secure. Whole House Water Filters Ask A Home Depot ExpertNo question is more likely to stir up a hornet’s nest of debate (if not brawl) among heating, cooling, and air conditioner (HVAC) professionals than “Which air filter should I use for my home?” Opinions vary so widely because over the years technicians have seen everything that the wrong kind of air filter can do to a home’s HVAC system: from coils, motors, and blowers too clogged by weak filters to burnt-out motors and controls because of too-restrictive filters.

HVAC air filters are important for removing contaminants from the air to improve your home’s air quality. The better the air quality, the better your HVAC system runs and the better your family’s health. Air filters are rated according to their Minimum Efficiency Reporting Value (MERV). Created by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), it’s a porousness scale that goes from 1 to 16, with most home air filters ranging from 4 to 13 MERV. The higher the MERV, the more contaminants that are removed from the air. Air filters are made from different materials in different thicknesses and sizes. These factors effect their MERV. Unfortunately, one of the biggest selling filter products, 3M’s Filtrete, do NOT use MERV, preferring its “Microparticle Performance Rating” (MPR) instead. Fortunately, there is a place to compare the numbers. Be aware, too, that some retailers also use their own rating system instead of MERV.

A decade ago, it used to be that if you had an HVAC system that used panel filters rated 6 through 9 MERV, putting in a MERV 11 or higher filter would restrict airflow (known as filter pressure drop). In turn, this would lengthen the system’s run-time, adding to your heating and cooling costs. This assumption is not entirely the case anymore. Newer pleated filtering media increases the filter’s surface area so that while the filter might be finer, there’s more area for air to pass through. The more pleats per foot, the better. The thicker the filter, the more surface area per pleat. So, while the filter pressure drop issue still has some impact, a 2009 Home Energy experimental test concluded that “…if no accommodations are made for the greater pressure drop of high-MERV filters, air flow and energy penalties are not likely to be severe — at least, not until the filter is loaded with dirt.” If you are renting and do not have allergy problems or pets or live in an area with excessive dust, then buying cheap spun fiberglass filters with a cardboard frame every three months should work out fine.

They’re not a good investment if you own your home because these filters are flimsy and prone to leak dust into the HVAC system. That dust can build up on coiling coils and motors and threaten to cost more over time in repairs than you might save from using cheaper filters. If you are going to invest in washable filters, then expect to pay more than $20 each for a 8 MERV filter. Cheaper washable ones will have loose filter media, especially after washing, and thus will perform poorly there after (caveat emptor). Keep in mind that disposable filters are more hygienic because all the dirt gets removed from your home when you toss out the filter. Higher MERV pleated filters do a much better job now that in the past. While the key to better filtration vs pressure drop lies in getting the most pleating per foot, it’s safe to say that newer filter designs have less air flow issues at higher MERV. More important, they are more effective than the median-grade pleated filters at improving indoor air quality (and potentially better health) for you and your family.

All the same, you still need to replace them every three months so price is a concern. For a standard sized 16″x25″x1″ 11 MERV filter, expect to pay $5 or more per filter but you can save a little when you buy them in packs of 12. Antimicrobial or electrostatic treatments also add to the filter’s cost. Some top brands within this general size range are Filtrete, Purolator, and Nordic Pure. Replacements for thicker (two to five inches) pleated 11+ MERV filters that require compatible framing to the air handler (see photo) and should follow the manufacturer’s recommendation because a thinner, cheaper filter won’t fit properly and so won’t work. While these filters are expensive – $45-$100 – they last a full year and work very well When it comes to air filters, all systems, homes, and air quality needs are going to be different. Ask yourself if the current type of filter you’re using is doing what you need it to do: filter dust and irritants from the air to protect your HVAC system and your family’s health.