HVAC stands for Heat, Ventilation, Air Conditioning System; it’s often referred to as the “Central AC”. An HVAC Filter is a purifying filter that you insert in your HVAC system to remove impurities such as dust, pet dander, and bacteria from the air flowing through your HVAC system. Not only does this improve the air quality within your home, it also protects your HVAC system from getting damaged. It provides an additional layer of Air filtration to your existing AirDoctor purifier.