Now that the duct system has been completely sealed and under vacuum, the tecnician will then begin to clean each individual duct starting with the supply side. We do this by using compressed air whips that tunnel through the ductwork swiftly and safely agitating any and all debris along the way. As the debris are being whipped up and pushed towards the mainline, the vacuum is sucking all the debris into our filters and out of your home. Professional air duct cleaning.