This invention discloses a building roof temp reducing and dust removal device including a water tank, pump water transmission pipe and a sprinkler in which the water tank in connected with the pump via the transmission pipe, the pump is linked to the sprinkler placed at the building roof via the transmission pipe and controller electrically. The said sprinkler is composed of a sprinkler and/or a sprayer, the controller is signal receiver with data number. The said tank connected with a collecting device, filled with alkaline additives or perfume is designed with an overflow connecting to the drain pipe, having the function of reducing city temp, easing up or eliminating the hot island effect. |