air purifiers can be very helpful in removing the dust, dander, pollen and dirt from the air that circulates through your force air system. depending on your household your heater filter may not be enough to remove these particles. the biggest factor is that there are many different types of furnaces filters with different mrev ratings so depending on which you use, that will determine how effectively you are removing the dust, pet dander, pollen and other microorganisms within your house.