ACFC cleans everything that has anything to do with the air handling unit, not some or most parts, but EVERYTHING!! First we hook up an industrial truck mounted vacuum with a 8 inch diameter hose to the furnace. This creates negative air pressure (or vacuum) throughout the air duct system. We then go to every hot and cold air register with what is called an "air wand or air gun". This air wand has a nozzle on it that is about 2 feet long, it's pliable, fits in between the fins of the registers, and puts out about 190+lbs of air pressure. We are able to angle the air wand to push all the dust and debris down the branch lines and into the main trunk lines. We then use what is called an "air snake" which has a reverse air nozzle on it. We drill 1 inch holes in the lines and trucks of the duct system. (which will be later plugged with a "duct plug"). We then send a reverse air spinner "snake" down each supply and return duct line and pull all the dirt and debris towards the main trunk line. Once those lines are clean and clear we start on the far side of the main line and push and pull the dirt and debris towards our powerful vacuum, both using the reverse spinner, push spinner and the whip that bangs around violently inside the trunk line pushing all the dust and debris back towards our vacuum where it catches it and takes it outside and into our truck so there is no mess involved. Also cleaning the fan compartment. Today this "push and pull method" is considered the most effective way to clean air ducts.