Indoor air quality may not be a matter of efficiency, but it has a big impact on the health of your home and those who live there. Aging furnace units, especially those that haven’t received regular maintenance, can put soot, dust, mold and other particles in constant circulation. These particles may cause anything from respiratory problems to serious illnesses that require hospitalization. New HVAC systems include options such as air purifiers, ventilators and humidity control to enhance air quality and keep your family safe.