Top Common Furnace Filter Sizes: Find the Perfect Fit for Optimal Air Quality There are many furnace filter sizes to choose from, depending on your home's household size and HVAC requirements. Choosing the right furnace air filters will ensure good air quality and save you from pollutants such as dust.... Top Common Furnace Filter Sizes: Find the Perfect Fit for Optimal Air Quality There are many furnace filter sizes to choose from, depending on your home's household size and HVAC requirements. Choosing the right furnace air filters will ensure good air quality and save you from pollutants such as dust....