To determine the correct filter size for your HVAC system, follow these simple steps:
1) Locate the existing filter: Find the location of your current HVAC filter. The filter is typically located either in the return air grille or in a lot near the air handler or furnace. (Make sure your HVAC system is turned off before measuring).
2) Remove the old filter: Carefully remove the existing filter. The dimensions should be printed on the side of the filter.
3) Measure length, width, and thickness: If the dimensions aren’t labeled, place the filter on a flat surface. Use a measuring tape or ruler to measure the length and width from edge to edge. To measure the thickness, determine the distance between the front and back surfaces of the filter.