Air filters are not designed to fit snugly into a system. In fact, if you have to force an air filter into or out, it's the wrong size, which is why standard sizes are usually half an inch smaller than advertised. It is essential that the filter is adjusted correctly so that it completely covers the air flow and can therefore trap the greatest amount of particles. Loose or too small filters allow air to pass through them without filtering anything.
At that point, you paid for a filter that doesn't work. To avoid this, you can choose a longer filter, since there is no need to close any doors or covers on the filter. The filter should fit the system without having to force it in and should not be so small that it can move freely inside the unit. If an air filter is too small, air gaps will be created and contaminants will bypass the filter material.
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. In addition, environmental factors, such as a nearby wildfire or an increased amount of dirt outside, can reduce the lifespan of an air filter. To determine which filter will have the maximum impact, the MERV rating helps you find exactly that filter. Dust, allergens, and pollutants will not leach out of the indoor air, since the air does not pass through the filter, enters the vent and returns back. Inserting an incorrectly sized filter may cause it to deform, damage it, or reduce its ability to function properly.
Now that you understand common air filter mistakes and how to avoid them, you're in a position to have clean air and a system that works efficiently. Timely replacing your oven filter is much easier when you know what size air filter you need. Unfortunately, if an air filter isn't fitted correctly, that air is likely to be full of impurities that can harm you unless properly filtered.
