How to Buy the Right Furnace Filter for Your HVAC System?

Photo by Mikhail Nilov:

If you are like most people, you probably don’t pay much thought to your furnace as long as it’s heating and cooling as it should. However, to maintain it running to its optimum performance — and to help prevent a possible failure — you need to either change or clean your furnace filter regularly. This will allow you to keep it working to its optimal performance.

Although it may sound simple, there are quite a few choices available for furnace filters. By selecting the wrong one, you could risk causing more harm to your furnace than good, and it is even possible that it will stop working altogether.

What to Look for When Purchasing Filters?

Your furnace filter’s main job is to shield your heating system from the dirt, debris, hair, and other impurities drawn into the system through the return duct. Your respiratory health can also benefit from improved IAQ (indoor air quality) in your house, provided by the filter.  

There are various kinds of furnace filters on the market. It can be perplexing to pick the right one, so we suggest that you do your research before buying.

Furnace Filter Types 

Some of the most common types include:

  • HEPA Filters: These high-efficiency filters can capture as much as 99 percent of the airborne particulates floating in your house. Although these HVAC filters are more expensive than other options, they have been proven to catch contaminants with a particle size of 0.3 microns or greater.
  • Pleated Filters: These are the kind of filters employed by most households since they are the most cost-effective and can be utilized in most settings. Although they do not perform as well as HEPA filters, they are significantly cheaper to purchase.
  • Electrostatic Filters: The fact that these home air filter systems may be cleaned makes them permanent in all but name. The filters’ electronic charge attracted to dust, smoke, and pollen allows them to remove contaminants from the air effectively.
  • Fiberglass Filters: These filters are good at capturing big dust particles, which is why they are most frequently seen in furnace systems. Compared to the other types of filters, this particular sort typically has the lowest price.


As there are many different kinds of filters, there are also many different sizes. The size is determined primarily by the furnace that you have. If you have paid attention to the measurements on the box that contains your filter, you will have seen that it is sized by thickness or depth, height, and length. For example, you may specifically need a 16x25x4 furnace filter. You can get the accurate filter size for your furnace by consulting the instructions provided by the manufacturer; alternatively, if you already have a filter, you can examine the filter’s frame to see if the size is printed or written there.

MERV Ratings

Minimum Efficiency Reporting Value (MERV) is a rating system that categorizes filters based on their density. The values of most filters vary from one to sixteen, with the higher number indicating the filter with the greatest thickness and density.

When figuring out what MERV rating is optimal for your furnace, it’s best to check with an HVAC professional.

The Bottom Line

There is a wide variety of sizing, thickness, and efficiency ratings available for filters. You must select the appropriate filter for your house’s HVAC unit since selecting the wrong kind of filter can cause harm to the heating system. So, choose wisely!