Your HVAC system uses a filter in the air ducts, usually near the units themselves, to help clean the air out. While these filters aren’t generally as refined as a HEPA filter, they still pick up many different particles, including dust, pollen, dust mites, and much more. However, HVAC filters are usually disposable: That means that they get filled up with particles, slowly clogging over time, and need to be replaced so that the system can keep cleaning the air. [Read more…]