Are all HVAC air filters the same?

No, HVAC air filters vary due to quality and size, and some have specs that others don't. Mostly we recommend using the filter your HVAC manufacturer recommends pairing up with your installed unit, however you may be tempted to try some other filter type for convenience or to remove extra debris from the air.

Filters have something called MERV ratings, which range from 1-20. MERV means "minimum efficiency reporting value". A higher MERV rating tells you that fewer contaiminants pass through, and it captures finer particulates. This seems obviously good, and it can be, but a filter that stops finer dust and debris particles will also build up more often, and pressure on your unit will rise. If your system has not been designed to function with this kind of filter, it can reduce your airflow within your home, impacting your comfort and energy bills. So what should you look for? Unless you're buying for a hospital, you simply 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 usually you will find that higher end systems have been made to work with a MERV rating of 8 or 11. All filters with a MERV rating of five should block most of the everyday nuisances everyone cares about such as pollen, pet dander, and dirt. While some filters claim to be able to capture mold spores, we recommend removing any mold from your residence you find, instead of trying to cover up the issue with a finer filter.

Often the packaging shows how often your filter ought to be replaced. There are one-month filters and there are 3-month filters. There are also filters that are one flat piece, and you have some that are pleated with supporting wire. In our experience, the accordian style filters hold up better, and are worth it for the extra durability.

You might also consider washable filters, also sometimes called reusable filters. Some homeowners like the environmentally friendly aspect of it, because they don't add to a wasteyard, and others believe it's more convenient to just slide out the filter and hose it off rather than making a run to the local hardware store for a filter of the right size. These filters are often designed to work several years and will save you cash over the long run, though they are more expensive initially. However, washable filters have to be dried out all the way before returning it back to stop 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 a period of time. Some washable filters have been built with updated technology, such as electrostatic air filters, that are meant to effectively improve the MERV rating.

Last, filters are made of different materials. Fiberglass filters are what we see most often, and are the disposable type. Polyester and pleated filters are known to catch more debris, but also decrease the airflow in your residence. And there are high efficiency particulate arrestance filters, or you might recognize the acronym HEPA. While you could be tempted to put in a HEPA filter, just consider that's like putting a MERV 16 filter in your HVAC system and it's not unlikely that your equipment was made to handle that kind of resistance.