The techniques to perform Air Duct Cleaning are accomplished by following an organized specification specific to a particular HVAC system. Often the method of cleaning is determined based on the accessibility to the inside of the ductwork. Access to the ductwork may be limited because of a solid ceiling, cement floor or old acoustical tiles. There may be an issue with reaching ductwork due to it's being high up off of the ground or in a difficult to access place. We may also find obstacles that need to be addressed and worked around. They may include, sheet metal screws, air flow dampers, turning vanes, reheat coils, fire dampers, fire probes, thermostats. Therefore the equipment that we choose to use may be a combination of various tools, hepa vacuums, pneumatic brushes and air compression to get the desired results for the job.