How to Read an Air Filter Size: A Comprehensive Guide

Are you looking to replace your air filter but don't know how to read the size? Don't worry, it's easier than you think! The size of a pleated air filter is always presented in a chain of three numbers: the first number represents the length, the second number represents the width, and the last number represents the thickness. Knowing the size of your air filter is essential for timely replacement and ensuring that your heating, ventilation, and air conditioning system (HVAC) system is running smoothly. In this article, we'll explain how to read an air filter size and what to do if you don't know what size air filter you need.

Checking the Size of Your Air Filter

Most filters have the sizes listed on the side printed on the side, including the length, width, and depth in inches.

They usually appear in that order. If your oven is missing the air filter and you don't know what size it should be, you can check the dimensions listed on the sides of the air filter frames or those printed with the largest size on the air filter package. These are usually referred to as nominal dimensions.Understanding Nominal DimensionsIt's important to note that the actual size of the air filter will be smaller than the nominal size of the air filter. This means that if an air filter is too small, air gaps will be created and contaminants will bypass the filter material.

As for depth measurement, standard air filters are nominally 1 (0.75 reais), 2 (1.75 reais) and 4 (3.75 reais) in depth.

Finding Out What Size Air Filter You Need

The first (and easiest) way to find out what size oven filter you need is to check the size of your old air filter. On air filter packages, this number usually appears below or next to the nominal size, and usually appears in a smaller font size. Once you know this number, you can easily buy a new filter with the same dimensions.Measuring Your Air Filter SlotIf it is easily accessible, measure the slot in your air filter housing or refer to your boiler's instruction manual for more information. A filter that is too small will leave a space where debris and particles can enter; a filter that is too large will not fit in the slot.

Basically, when you take measurements of an air filter, you just have to round it to the nearest inch to find out what size of filter you need to buy.

MERV Rating

Finally, keep in mind that a higher MERV rating means that your filter better maintains air quality and removes environmental contaminants. So when shopping for a new air filter, make sure to check its MERV rating as well as its dimensions.

Ericka Boughner
Ericka Boughner

Certified travel junkie. Infuriatingly humble twitter geek. Hardcore food scholar. Award-winning travel buff. Award-winning travel lover. .