Air conditioning and HVAC units require a specific size filter to operate correctly and efficiently. Most units use standard-size filters, but some require the purchase and installation of a custom-sized air filter. Filters are labeled with three-part dimensions, which include the length, width, and depth or thickness. The easiest way to identify the size of the AC filter is to remove the existing filter from its slot and examine the filter frame.
Typically, the filter size is printed along the edge of the filter frame. Note that the size shown in bold type on the filter frame is the nominal size of the filter, which is likely to differ from its actual size. If the actual dimensions do not appear in small print on the filter frame, it is recommended to measure the filter to check. When purchasing a custom-sized air filter, it is important to remember the difference between the nominal and actual size. The actual size of your air filter should be 0.25 -0.5 smaller than the slot or frame itself.
If you have to jam the air filter to install it, try a different brand of oven filter or a custom-sized air filter with a slightly smaller actual size. Central return air grilles are usually found in the hallway, ceiling, or hallway wall of your home. If the return grille is in the ceiling, you may prefer to use a filter that has a slightly larger actual size, so that it does not fall on you when you open the vent. The most common AC filter sizes and oven filter sizes are 16x20x1 air filter, 20x20x1 air filter, 16x25x1 air filter, and 20x25x1 air filter. If you have a system that uses a whole-house filter, you may have a choice from MERV 8 to MERV 16, depending on your HVAC system.
If you have a system that has the option of a highly efficient MERV 15 filter, such as Bryan and Carrier, offer germicidal air purifiers. Changing the filter regularly will improve the efficiency of your HVAC system, so it cools, heats or cleans the air with less energy. When buying an air filter, it's important to keep in mind that industry standard is to make filters measure a little smaller than their slot or frame, so they can easily slide into place without bending or breaking. Honeywell, Hunter and Whirlpool have several models of room air purifiers available, so it's important to check compatibility before purchasing a replacement. To ensure proper fitment for your HVAC unit or oven, make sure to round down to the nearest integer when determining nominal size and select an actual size that is 0.25 -0.5 smaller than its slot or frame. Improperly sized air filters can put excessive strain on your HVAC system, damage it, and increase your energy bills.
If you're looking for a retailer near you that sells custom-sized air filters, you might struggle to get lucky. Lennox filters show part number X0583 and Honeywell part numbers FC100A1029 and FC35A1001 on their frames along with compatible filters. Oven filters sizes for standard sizes (also known as standard AC and oven filter sizes) and hard to find are included in lists with actual sizes and MERV options. For many people, air filtration is a confusing topic where questions are often not asked or answered. It's best to have a little wiggle room in the slot of your HVAC unit so you can easily slide the filter in and out without it bending or breaking.
When purchasing an oven or AC filter, make sure it fits snugly into its compartment with a little space around its edges.
