Are all HVAC air filters the same? No, HVAC air filters vary due to quality and size, and some have technology that others don't. In most cases we recommend purchasing the filter your HVAC manufacturer recommends pairing up with your installed unit, however you could be tempted to try another filter type for convenience or to remove extra debris from the air. All filters have MERV ratings, which range from 1-20. MERV is an acronym for "minimum efficiency reporting value". A higher MERV rating tells you that fewer particles pass through, and it catches finer particulates. This sounds fantastic, and it can be, but a filter that catches finer dust and dirt will also stop up more often, and pressure on your HVAC equipment will rise. If your system has not been designed to operate with this kind of filter, it can reduce your airflow within your residence, putting the hurt on your comfort and energy bills. So what should you know before you buy? Unless you're buying for a hospital, you simply don't need a MERV rating above 13. Truth be told, most residential systems are specifically designed to work with a filter with a MERV rating below 13, and usually you will learn that higher end systems have been made to operate with a MERV rating of 8 or 11. All filters with a MERV rating of at least five should eliminate most of the major nuisances we know about such as pollen, pet dander, and dust. While some filters claim to be able to capture mold spores, we recommend hiring a pro to clean out any mold from your residence you find, instead of trying to cover up 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. Additionally we have filters that are made flat like screen windows, and you have some that are built accordian style with supporting wire. In our experience, the accordian style filters hold up better, and are worth the extra pennies. You might also consider washable filters, also called reusable filters. Some homeowners like the environmentally friendly aspect of it, because they don't want to add to a landfill, and others consider it more convenient to quickly yank out the filter and wash it off rather than making a special trip to the local hardware store for a filter of the proper size. These filters are often created to last several years and will save you money over the long run, though they are more expensive initially. However, washable filters should be dried out one hundred percent before inserting it back to prevent mold growth in your ductwork. In addition, most washable filters typically have a MERV rating between 1 and 4, and they lose their efficiency over time. Some washable filters have been built with updated technology, such as electrostatic air filters, that are meant to basically improve the MERV rating. Finally, filters are built with different materials. Fiberglass filters are what is commonly used, and are the disposable type. Polyester and pleated filters normally 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 buy a HEPA filter, just understand that's like putting a MERV 16 filter in your HVAC system and it's highly unlikely that your equipment was built to handle that kind of resistance. Back To Frequently Asked Questions