METHOD AND DEVICE FOR CLEANING PHOTOCATALYST-COATED EXTERIOR SURFACE

PROBLEM TO BE SOLVED: To provide a method and a device for cleaning a photocatalyst-coated exterior surface capable of efficient cleaning by cleaning the photocatalyst-coated exterior surface by use of a self cleaning operation even when there is a cause of not exerting the self-cleaning operation such as no-irradiation with the sun shine (UV) or the shortage of rain water, thereby preventing the damage and separation of the photocatalyst coat caused by conventional cleaning means.SOLUTION: Cleaning range closing means 13 forms a closed space by enclosing the cleaning range of the photocatalyst-coated exterior surface W, and UV application means 15 for applying UV onto the exterior surface W when cleaning, thereby activating photocatalyst to weaken the adhesive force of adhering dirt. Water sprinkling means 18 sprinkles water so as to form a water film to wash away from a upside to a downside, thereby cleaning the exterior surface W. Then, air is blown, by draining and drying means 22, onto the cleaned surface W washed away with the water film to be drained and dried, thereby preventing dirt such as dust from adhering again. Moreover, water collection and circulation means 23 collects dirty water, removes the dirt with a filter, and circulates the water, thereby cleaning the exterior surface W with minimum water.