Are all HVAC air filters the same?

No, HVAC air filters vary by quality and size, and some have technology that others don't. Mostly we recommend using the filter your HVAC manufacturer recommends pairing up with your installed system, but you may be tempted to try a different filter type for convenience or to remove additional pollutants from your home.

Filters have something called MERV ratings, which range from 1-20. MERV is an acronym for "minimum efficiency reporting value". A higher MERV rating equates to fewer particles pass through, and it captures finer particulates. This sounds fantastic, and it can be, but a filter that stops finer dust and dirt will also build up more often, and pressure on your system will increase. If your system has not been designed to work with this kind of filter, it can reduce your airflow around your house, affecting your comfort and energy costs. So what should you look for? Unless you're buying for a hospital, you probably don't need a MERV rating above 13. In fact, most residential systems are specifically designed to work with a filter with a MERV rating below 13, and frequently you will discover that higher end systems have been made to function with a MERV rating of 8 or 11. All filters with a MERV rating of 5 should block most of the everyday nuisances people care about such as pollen, pet dander, and dirt. While some filters claim to be able to catch mold spores, we recommend hiring a pro to clean out any mold from your home you find, instead of trying to delay the issue with a finer filter.

Often the packaging indicates how often your filter should be replaced. There are one-month filters and there are 3-month filters. There are also filters that are made flat like screen windows, and you have some that are ridged with supporting wire. In our experience, the accordian style filters hold up better, and are worth a little extra.

You may also consider washable filters, also known as reusable filters. Some homeowners like the environmentally friendly aspect of it, since they don't add to a wasteyard, and others consider it more convenient to simply yank out the filter and hose it off rather than making a run to the local hardware store for a filter of the proper size. These filters are often designed to endure several years and will save you cash over those years, though they are more expensive initially. However, washable filters have to be dried out thoroughly before placing it back to eliminate mold growth in your ducts. 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 tech, such as electrostatic air filters, that are meant to basically improve the MERV rating.

And lastly, filters are composed from different materials. Fiberglass filters are what we see most often, and are the disposable type. Polyester and pleated filters normally catch more debris, but also lessen the airflow in your house. And there are high efficiency particulate arrestance filters, or you might recognize the acronym HEPA. While you may be tempted to buy a HEPA filter, just consider that's like putting a MERV 16 filter in your HVAC system and it's very unlikely that your unit was made to handle that kind of resistance.