When it comes to furnaces, there are a variety of types and sizes. It's important to know what size and type of filter you need before replacing your filter. To determine the size, look at the old oven filter and take note of its size and type. The oven filters should fit securely, but there is no need to force them into position.
If you have to force the filter into its slot, it's probably too big. Inserting an incorrectly sized filter can cause it to deform, damage it, or reduce its ability to function properly. The filters are slightly smaller than their slot for easy replacement. In some cases, HVAC units may need a filter with unique or unusual dimensions. In these cases, it is necessary to order a custom filter.
The easiest way to identify the size of an air conditioner filter is to remove the existing filter from its slot and examine the filter frame. If the ventilation grille is on the roof, you may prefer a filter that has a slightly larger actual size, so that the filter doesn't fall on you when you open the vent. To make sure that the next filter you buy is the correct size for your system, you must measure the interior dimensions of the air filter inlet. For common brands of air conditioning systems such as Goodman, Lennox, Trane, Rheem York, Coleman and Carrier, most standard air filter sizes will work. The actual size is the actual dimensions of the filter by length, width, and thickness. It's important to understand the difference between nominal and actual filter sizes.
If you have an old filter from your oven on which the dimensions are printed, then determining the size is not a problem. When you buy a filter online, the actual size appears at some point in the product vignette or in the product description. For example, a size of 20x30x1 may appear on the filter label, but if you measure the filter you will see that the actual size is smaller than the nominal air filter size of 20x30x1. If you have to clog the air filter to install it, try a third-party oven filter or a custom-sized air filter with a slightly smaller actual size. You can find the recommended filter size for your unit model in tables titled “Find your air conditioner and oven filter by brand, model number, and size”.
Please note that the sizes of the air conditioner and oven filters must be smaller than the measurements of the filter compartment. If the filter isn't the right size, either too small or too large, air will flow around the filter instead of through it and, as a result, not all of the air will be filtered. By learning more about air conditioning and heating filter sizes, you can make sure you find the perfect size for your home. As an expert in furnace filters, I recommend taking careful measurements before purchasing a new one. Make sure that you know what type of furnace you have and what type of furnace filters it requires. Additionally, be aware of nominal versus actual sizes when ordering online so that you get exactly what you need for your system.
