Are all HVAC air filters the same?

No, HVAC air filters vary due to quality and size, and some have features that others don't. Usually we recommend purchasing the filter your HVAC manufacturer recommends pairing up with your installed equipment, though you could be tempted to try some other filter type for convenience or to remove more debris from your residence.

Filters have MERV ratings, which range from 1-20. MERV is an acronym for "minimum efficiency reporting value". A higher MERV rating means fewer particles pass through, and it blocks finer particulates. This seems obviously good, and it can be, but a filter that stops finer dust and dirt will also clog up more often, and pressure on your unit will increase. If your system has not been engineered to operate with this kind of filter, it can decrease your airflow within your home, impacting your comfort and energy expenses. So what should you do? Unless you're buying for a hospital, you definitely don't need a MERV rating above 13. In fact, most residential HVAC systems are specifically designed to work with a filter with a MERV rating below 13, and frequently you will find that higher end systems have been made to function with a MERV rating of 8 or 11. All filters with a MERV rating of five should catch most of the major nuisances people care about such as pollen, pet dander, and dust. While some filters claim to be able to snag mold spores, we recommend hiring a pro to clean out any mold from your home you find, instead of trying to cover up the issue with a finer filter.

Often the packaging tells how often your filter should be replaced. There are one-month filters and there are 3-month filters. You also have filters that are two dimensional, flat screens, and you have some that are pleated with supporting wire. In our experience, the accordian style filters hold up better, and are worth the extra pennies.

You may also consider washable filters, also known as reusable filters. Some homeowners like the environmentally friendly aspect of it, since they don't want to add to a landfill, and others consider it more convenient to simply slide out the filter and clean it off rather than making a special trip to the local hardware store for a filter of the proper size. These filters are often designed to work several years and will save you cash over those years, though they cost more initially. However, washable filters should be dried out one hundred percent before returning it back to eliminate mold growth in your vents. In addition, most washable filters reportedly have a MERV rating between 1 and 4, and they lose their efficiency over the years. Some washable filters have been built with new technology, such as electrostatic air filters, that are meant to basically improve the MERV rating.

Last, filters are built with different materials. Fiberglass filters are what is commonly used, and are the disposable type. Polyester and pleated filters are known to catch more debris, but also lessen the airflow in your residence. And there are high efficiency particulate arrestance filters, or you might recognize the acronym HEPA. While you may be tempted to use a HEPA filter, just understand that's like putting a MERV 16 filter in your HVAC system and it's very unlikely that your equipment was built to handle that kind of resistance.