What are the most common air filter sizes?

Let's take a look at the most common oven filter sizes and where to buy oven filters. To the right of the filter, it also includes the actual filter size, which are the true measurements of the filter dimensions by length, width, and depth. When buying an air filter, it's important to keep in mind that the air filtration 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. They are seven times better than a standard filter for removing dust and other particles and have a longer service life than other filters (up to two more years).

If the return grille is in the ceiling, you may prefer to use a filter that has a slightly larger actual size, so that the filter doesn't fall on you when you open the vent. If you can't find your size in the store or need a custom-made air filter, online retailers are probably the best option for you. Most air conditioning and HVAC units use standard-size filters, but some require the purchase and installation of a custom-sized air filter. Unfortunately, that's not the case: there are standard sizes of approximately 20” for air filters and none have the same measurements.

Each mark may have actual sizes and that are different from the nominal size (the size on the label is sometimes a rounded size) that appears on the filter label. Installing several 1-in-a-slot air filters, for example, can cause costly damage to your air conditioning unit, as residential ovens are not equipped to handle this level of airflow restriction. Placing the filter backwards may cause the filter to collapse, which will cause airflow to circulate around the filter. Starting from actual sizes, round measurements to the nearest whole numbers when ordering new air filters.

However, you can choose not to use factory-installed filter grids and have an HVAC professional install an external filter grid to get a coarser filter. Most major retailers, such as Walmart, Target, and Home Depot, offer air cleaners, albeit with a different variety of options and brands to choose from.