Your Comfort Plus HVAC unit may use a replacement whole house residential air cleaner filter in a 5-inch. depth. These sturdy filters are the component that cleans your indoor air and maintains your system. Changing these filters 1-2 times per year is the best way to keep your unit running efficiently. Choose below from several MERV ratings and four (4) sizes - 16x21x5, 16x26x5, 20x21x5, 20x26x5. Contact U.S. Home Filter today for help finding the correct Comfort Plus replacement whole house air filter that's right for your home.