Dust, allergens, and pollutants can be kept from entering your indoor air if the air passes through a filter. Filters are designed to work when air is forced through them, as they create resistance. If you leave a gap of 1 inch, the air will bypass the filter and enter the vent, which will worsen the situation. To answer the question, yes, you can cut off an air filter if you know what you're doing and if the filter isn't weakened too much from the cut. When you purchase an air filter, it's important to look at the size printed on the side of the frame.
This size is usually given in inches and includes the length, width, and depth. For example, it may say “16x25x1”, where 16 is the length, 25 is the width, and 1 is the depth. If you use a thin air filter with a high MERV rate, it can restrict airflow and cause excessive wear and tear. When buying a custom-sized air filter, remember that there is a difference between the rated size and actual size. Some filters fit perfectly without any modifications, but this isn't always the case if you have ducts that don't follow standard designs.
An air cleaner is a separate unit that can be configured with your HVAC system. It's not always easy to find a retailer near you that sells custom-sized air filters.If your filter isn't the right size, either too small or too large, air will flow around it instead of through it. This means that not all of the air will be filtered out. Thicker filters last longer because they have more square feet to capture and retain particles.
The MERV rating measures how effective an air filter is at removing particles from the air. There are several great options for buying air filters online and having them delivered to your door. Please note that the actual size of the air cleaner will be smaller than its nominal size. Flat panel filters are usually cheaper but less effective. For common HVAC brands such as Goodman, Lennox, Trane, Rheem York, Coleman and Carrier, most standard air filter sizes should work.