Get The Right Size Furnace Filter Every Time
By: Krysten C.
Spring is quickly approaching. Allergens are prepared for battle. Now is the time to change furnace filters. However, knowing the size of your furnace filter is crucial to replacement as well as a positive shopping experience.
HOW DO I KNOW WHAT SIZE MY FURNACE FILTER IS?
The easiest way to find the size of a furnace filter is to look for a part number or size on the furnace filter that is currently in use. When looking for the size of furnace filters, we are really looking for the nominal dimensions.
NOMINAL VS ACTUAL DIMENSION
The nominal dimension is the actual dimension of a furnace filter, rounded to the nearest inch. If your furnace filter has the actual dimension of 15 ½ x 20 ¼ x ¾, the nominal dimensions would be 16 x 20 x 1. The nominal dimension is what you want to use when searching online or in store for a replacement furnace filter.
Some websites, like DiscountFilters.com, will list both the nominal and the actual dimensions for the furnace filter since it is typical for the actual size to be undercut ½”.
If you can’t find the part number or nominal dimensions, find them yourself. Use a tape measure and record the exact measurements of your furnace filter. You can do so by measuring the length, by the width, by the depth/thickness.
Note: If you don’t want to pick up the measuring tape, then pick up the phone. When in doubt, customer representatives are available to assist you and make sure what you need is what you get.