No, we do not use brushes. Brushes are round and most ductwork is rectangle shaped, so the brushes cannot reach both sides of the inside of the ductwork. Brushes cannot bend around or reach into corners, so as soon as they hit a turn in the ductwork, they go no further. Also brush systems are powered by very weak systems and the vacuum cannot possibly remove all dust, dirt and debris inside your ductwork.  We utilize a high pressure compressed air and power vacuum truck system. The power vacuum truck is capable of moving 15, 855 cubic feet of air per minute. The high pressure compressed air-patented Viper Whip system has 220lbs of pressure and 200 cubic feet of air per minute. Our system can easily remove the most stubborn stuck-on debris inside the ductwork, especially in the corners.