Does Air Filter Depth Really Matter?

Learn how depth affects efficiency & life of an air filter & how to choose one for your HVAC system.

Does Air Filter Depth Really Matter?

A deeper depth of air filter can improve filter life and efficiency, as well as make it easier for air to enter and exit the filter. When it comes to air filters, the thickness or depth of the filter is an important factor to consider. Most air filters are 1 inch thick, but some systems can accommodate filters 2 to 5 inches thick. In our tests, we found that the thicker the filter, the better it works and the longer the replacement intervals.

This means it's better for you and your heating, ventilation and air conditioning (HVAC) system. The depth of oven filter sizes range from one inch to five inches. An incorrectly sized HVAC air filter can compromise your entire system. A filter that is too small or large will not create the seal needed to filter all the air.

The gaps will allow dust, dirt and germs to bypass the filter and potentially re-circulate in the air of your home. When it comes to MERV ratings, 4-inch filters cover a higher range than 1-inch filters, with a slight overlap. With a 4-inch filter, you'll get at least 8 MERV rating. With higher ratings of up to 16, you can put controls on supermicro contaminants such as bacteria, viruses and dust particles.

To ensure that the next filter you purchase is the correct size for your system, you must measure the inside dimensions of the air filter inlet. The easiest way to identify the size of the air conditioner filter is to remove the existing filter from its slot and examine the filter frame. There are a number of great options to buy air filters online and have them delivered to your doorstep comfortably. Since HVAC technicians come to your home and evaluate your specific unit, they know what type of filter your oven can handle and what is best for your system. Homeowners who want to upgrade their air filters to a greater depth just need to do a little more work to make it possible. With all the numbers and metrics printed on the oven air filter box, it's easy to feel overwhelmed.

The higher the MERV rating, the smaller the contaminants a filter can trap, which also means that it will clog up faster. If you need a high merv filter for air purity due to respiratory problems, buy an external air purifying device. We are leaders in heating and air conditioning repairs, installations, maintenance and advanced air care solutions. For example, since you will be changing 1-inch high MERV filters more often than 4-inch filters (see maintenance section above), you could save money with a 4-inch filter depending on the MERV you get. If a certain amount of dirty air passes through both, the number of “unclogged” pores will be greater in a coarser filter than in a thinner one. If the old oven filter has already been discarded, refer to the oven owner's manual for this information. For example, Home Depot mainly carries Honeywell brand air filters, while ACE Hardware mainly carries Filtrete.