Choose the Right Air Filter for Your Home’s HVAC System

HVAC systems have filters that help to pull dust, debris, and pollutants out of the air. This is partly to improve the air quality in your home, and partly to protect the inner workings of your HVAC system itself. The filter is relatively unimposing and inexpensive, and it serves a crucial role in the continued smooth operation of your air conditioner, heat pump or furnace. Many homeowners tend to lump all “furnace filters” into the same general category, despite the fact that just like any other product, these filters come in a wide range of quality and efficiency.

When choosing an air filter for your home’s HVAC system, it’s important to know the differences between options available in residential filters. That way you’ll be better equipped to choose the best one for your heating and cooling system and the air quality situation in your particular home.

What Role Does the Air Filter Play in Your HVAC System?

Before getting into a discussion of how to choose an appropriate HVAC filter for your home, it’s important to understand the role that the filter plays in your heating and cooling system. The filter is usually located next to the furnace or air handler (for an AC or heat pump), at the spot right before a powerful fan draws “supply” air into the equipment. The filter sifts out airborne particles – including household dust and other, various unwanted contaminants (such as pet dander, hair, dust mites, pollen and mold spores) – before the air gets drawn into the workings of the system and heated or cooled. This protects sensitive HVAC components from dirt and dust, preventing friction and impaired efficiency. In addition, if the filter is sufficiently efficient, it will keep many airborne contaminants out of your indoor air.

How Do You Choose the Right Filter for Your HVAC System?

Before deciding on the proper air filter for your home’s heating and cooling system, consider your needs and priorities. If you have specific concerns about air quality, perhaps due to a family member with respiratory issues or severe allergies, or maybe because of external or internal factors that make your indoor air especially polluted, you’ll want to consider a high-efficiency filter. These filters sift out the vast majority of airborne particulates, including some of the smallest.

If you don’t have special health concerns related to air quality or another factor that makes your indoor air particularly dirty, then a mid-efficiency HVAC filter will likely be sufficient. These remove the great majority of common household contaminants from your indoor air.

It’s important to keep in mind that generally speaking, the more efficient a home air filter is, the more frequently it will need to be changed. If you imagine the filter as a net, collecting everything moving through the HVAC system, then the finer the net, the more quickly it will fill up and become blocked by what it collects. A high-efficiency filter should be checked at least monthly, and maybe even more frequently, depending on the circumstances in your home.

MERV Ratings Can Help with Your Choice of HVAC Filters

When shopping for an HVAC filter for your home’s heating and cooling system, the MERV rating system (Minimum Efficiency Reporting Value) can be a big help. (Of course, the first thing you’ll want to do is look at the filter you’re replacing so you’ll know the proper dimensions. If possible, take an old filter with you when you’re shopping so you can be sure the new one will match the dimensions of your system.)

Cheap, flat-panel fiberglass filters typically carry MERV ratings of 1-4. They’ll remove up to 80 percent of airborne particles 50 microns and bigger, but won’t remove any more than 25 percent of smaller particles in the 3- to 10-micron range. For most homeowners, you want something that does a better job of clearing out the air in your home. A better choice, and one that’s only a few dollars higher in price, is the air filters in the MERV 5-12 range. They remove a significantly higher percentage of particulates without restricting system airflow. (Resist the urge to just buy the “best” filter you can find – filters with a very high MERV rating are probably overkill for most home systems, and may restrict the airflow too much to be good for your HVAC system.)

How the filter affects airflow through your home’s HVAC system is an important consideration when choosing the right filter. A filter that’s “too efficient” – with overly dense filtration media – may impede airflow through your system, which can erode performance and energy efficiency, and potentially damage the equipment. If, for health or other reasons, you need an ultra-high-efficiency air filter for your HVAC system, you may need to consider retrofitting your equipment so it will work with the denser filter without restricting airflow. If this situation applies to you, call your local HVAC company to talk to them about the best way to protect the health of your family while also avoiding damage to your heating and cooling equipment.

When shopping for an air filter, if you can’t find the MERV rating on the packaging – and yes, it can be difficult to find – ask a clerk at the store or look up the product online. If you still can’t find that information, it may be because the manufacturer uses a different rating system for filters (such as MPR or FPR). That alternate rating should be provided on the packaging, with an explanation of what it means. If not, you can find the information online.

Keeping your HVAC air filter fresh and free from obstructions is one of the easiest and most effective ways of maintaining your home’s heating and cooling system. You can make the filter change yourself and save yourself potential headaches down the road. Your HVAC technician will also happily change the filter during their twice yearly heating and cooling system maintenance – but it will probably need to be done more often than those visits.

Here in Cincinnati, you can schedule your regular HVAC system maintenance with us here at Jansen Heating & Cooling. We’re happy to be your partner in your home’s heating and cooling system maintenance.