Air duct cleaning is done every three to five years depending on the type of system and how frequently it is used. After a cleaning is complete, homeowners still need to maintain the integrity of their vents and returns by performing routine maintenance. One of the most important steps is to ensure that dust and debris do not contaminate the surface once again by following a few of these simple, dust and debris-free tips: Preventing Overall Contamination When it is time to change out the air filter, air duct cleaning recommends utilizing a high-efficiency filter on a furnace and cooling system. Filters should also be changed out regularly to avoid any debris or dust backup into the furnace or cooling system itself. When a filter appears clogged or full during changing, that is a good indicator it needs to be changed more frequently. Always ensure that all filters are installed and there are never any missing filter gaps where debris can pass into the returns. Cooling coils and dri...