If you looked at the title of this post and thought, “Wait, aren’t those the same thing?”, then we recommend you read further. Homeowners are often confused about their options when it comes to getting air filters and air purifiers to improve their household indoor air quality. It often starts with mistaking the job of the standard filter that’s part of the HVAC system—also called the “furnace filter” or “AC filter” (one filter usually does both jobs.)
There’s an important difference between what we call a whole-home air filter and the filter located on the HVAC cabinet or behind the return air duct in the house.