When it comes to air filters, size matters. It's important to choose the right size air filter for your home in order to ensure that your HVAC system is running efficiently and that you're getting the best air quality possible. But how do you know what size air filter you need? It's a combination of knowing how to measure an air filter and understanding that the dimensions you see may not be those of the actual size. When buying a custom-sized air filter, it's important to remember the difference between nominal and actual size.
The nominal size is the rounded measurement used to match the correct filter to the air cleaner slot of the accessory. The actual size is the actual size of your air filter, but not necessarily the size that appears online or on the air cleaner packaging. It is always best to take the measurements yourself with an accurate measuring device. Money may not be the only thing you'll save; changing air filters helps prevent premature oven failure.
By using a properly sized filter and changing it regularly, you can experience cleaner indoor air and fewer system problems. If the filter is too small, it will loosen and some of the air (and dirt) will not pass through the air filter. So 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. In this case, you'll want to round down to the nearest integer to determine the nominal size of the air cleaner. These numbers relate to the standard size of your home's return ventilation grilles, responsible for controlling the movement of air to and from your HVAC unit.
Starting from actual sizes, round measurements to the nearest whole numbers when ordering new air filters. You can also scroll down and use the air filter size chart to choose the right size and pay quickly.
How To Measure An Air FilterWhen purchasing a custom-sized air filter, it's important to remember the difference between nominal and actual size. Once you determine the exact dimensions that work best for you, place an order for your filter size with the exact fraction or decimal of your preferred measurements. Otherwise, you may get a different actual size than you expected. This is a standard size air filter chart.
Note that the actual size of the filter is smaller than the size printed on the oven air filter.