Turn off the air conditioning before cleaning the vents.
Use a vacuum cleaner with a cleaning attachment to suck up loose dust and dirt from the air conditioning vents.
Use a feather duster with an extension pole to clean hard to reach vents, such as those found in the ceiling.
Detach the air conditioning vents if you wish to clean them more thoroughly. Use a screwdriver to unscrew the screws holding the vents in place. Pull the vent coverings off the wall, floor or ceiling.
Wipe the vents down with a cloth using soap and water to remove any remaining dust or dirt. Use a small sponge paintbrush to help clean in between the slots in the vent.
Allow the vents to dry before re-attaching them.