Built In Vacuum
Built In Vacuum Systems are designed to remove dirt and debris from homes and buildings, sending particles through tubing located in the walls to a receptacle in a remote area. The built in vacuum power unit is permanent and typically installed in a basement, garage or storage room with the receptacle. Inlets are installed in baseboards throughout the building (on average one inlet per 600 square feet) that attach to power hoses and other central vacuum accessories to remove dust and particles from a room. Most power hoses typically have a power switch located on the handle.
The wall vents are connected to the power unit by tubes that can be run through the attic or the cold air returns. The unwanted debris is transported out of the room, through the tubing, to the power unit and then deposited into a canister or bag. These bags and canisters need to be emptied once every three months. Automatic dustpans can also be installed which enables a person to sweep debris directly into a wall vent using a standard broom.
See http://en.wikipedia.org/wiki/Central_vacuum_cleaner for more information.