If you're looking to replace your air filter, it's important to know the exact size of the filter you need. The easiest way to do this is to measure the length, width, and depth of your current filter. Most air filters have their size printed on the side of the frame, so you can simply look for that. If not, use a ruler or other measuring device to measure the exact length, width, and depth (thickness) of your air filter.
Round each dimension to the nearest integer to determine the nominal filter size. When taking measurements of an air filter, you just need to round the nearest inch to find the dimensions of the filter you need to buy. For example, if your filter is 16x25x1, where 16 is the length, 25 is the width, and 1 is the depth, then you would round each number up or down to get a nominal size of 16x25x1. It's important to note that some HVAC systems require more than one air filter, so make sure you have the correct measurements for all of them. Additionally, if standard sizes don't work for you, you can build a custom air conditioner or oven filter and choose specific dimensions.
When changing oven filters, it's important to know what size oven filter you have. Most ovens have an air filter in the return vent, so changing the filter is easy and can be done from inside your home. Look for where the return duct connects to your oven and there should be a plate that covers the slot where the air cleaner enters. It's also important to keep in mind that improperly sized air filters can put excessive strain on your HVAC system, damage it, and increase your energy bills.
Jamming a large filter where it doesn't belong can damage the HVAC system and won't clean the air properly. Finally, it's important to note that according to Energy Star, filters must be changed every month during peak summer and winter months when your HVAC system is operating at its maximum capacity. This will help ensure that your HVAC system is running efficiently and effectively.