The Air Filter Plays a Key Role in Your HVAC System; Choose Wisely

You wouldn’t think such an insignificant component would play such a big role in the success of a mechanical system. Yet, air filters that work with your forced-air heating or cooling system are essential to its performance and energy efficiency. In most cases, they cost under $15, and the most common variety costs just a few bucks. Since the work performed by the HVAC air filter is so important, it’s essential that you choose the right filter for your HVAC system and home.

What Does the Air Filter Do?

Is that a trick question? It filters the air, of course. However, there’s a lot more involved in the context of how the HVAC air filter functions in the mechanical process of heating and cooling indoor air in a forced-air system. In other types of heating and cooling systems that don’t rely on circulating conditioned air (e.g. radiant or baseboard heating), air filters aren’t used.

Typically, in a residential forced-air HVAC system, the filter is slid into a slot near where the ductwork connects with the furnace, air conditioner or heat pump. When the system is operating, the filtration media in the air filter sifts out airborne particulates, anything from dust mites to pollen to pet dander to carpet fibers (or generically speaking, dust and debris). High-efficiency air filters will remove mold spores and other tiny contaminants from household air.

Benefits of an HVAC Air Filter

The two main benefits that accrue from an air filter working in your heating or cooling system are:

• Protection of HVAC equipment. When dust and debris are removed from the air before it enters the furnace or AC, they can’t settle on sensitive components of the machinery. Over time, dirty equipment will experience increased friction and won’t operate as efficiently. It also will experience more breakdowns.

• Enhanced air quality. When contaminants are filtered from the indoor air, they can’t circulate throughout your house. This is a benefit to family members who have allergies or respiratory ailments. Some of the contaminants may even be viruses or bacteria, though only higher-efficiency air filters will remove those from the air.

How Does One Find the Right Air Filter

When shopping for HVAC filters (at hardware, home improvement and even grocery stores), look for the MERV (minimum efficiency reporting value) number on the packaging. The numbers run from MERV 1 up to 20, though for the most part, residential air filters don’t exceed 16. The higher numbers reflect higher efficiency. (In this context, efficiency means how well the filter removes the smallest particulates from indoor air.) For regular residential use, filters with a MERV range of 8-14 offer the ability to clean the air while maintaining airflow.

When MERV numbers rise into the mid to high teens, the dense filtration media in the filter may start impeding system airflow. This reduces efficiency and performance, and can lead to more system wear and tear. This is because the HVAC equipment is working harder and longer to push air through the filter.

Avoid buying the cheapest, flat-panel filters, the ones that sell for a couple dollars. For a few more dollars, you can get much-improved efficiency and air quality.

While the MERV rating system is the most common, some air filter manufacturers use other efficiency ratings, including MPR (Micro-Particle Performance Rating) and FPR (Filter Performance Rating). You can find explanations of these systems online.

Don’t Forget to Maintain Your Air Filter

Once you’ve selected the right air filter for your furnace, air conditioner or heat pump, make a commitment to inspect it every month that your heating or cooling system is in use. If it’s full of dust and debris, replace it with a fresh filter, or if it’s a reusable filter, give it a good cleaning.

A dirty or clogged filter will reduce energy efficiency and performance, since the equipment has to work longer and harder to move air through the filter. It has similar detrimental effects to an overly efficient filter that impedes airflow.

Talk to your trusted Cincinnati HVAC contractor about which air filter is best for your forced-air heating and cooling system.