Did you know: about 40,000 dust mites can «thrive» in only one ounce of dust. Imagine how many are living in your ductworks? Dust mites are in your home and mine. They are tiny insects that are so small they are invisible to the naked eye. However their feces and body parts are proven to cause asthma attacks for people who are allergic to them. While not connected to your HVAC system, your dryer vents also need to be cleaned on a regular basis. Dryer vents are entirely self-contained, and their sole purpose is to move air from your clothes dryer to the outside. If they’re not cleaned on a regular basis, lint can block off the vents, keeping the hot, dirty air inside your house. In a worst-case scenario, if there’s not enough circulation, blocked vents can actually be a fire hazard.