CLEAN ROOM

摘要

A dust discharge promotion surface (15-1) of a dust discharge assist member (15) is placed to face the upper surface (10-1) of a heat radiation body (10) such as a production facility. The space between the upper surface of the heat radiation body and the dust discharge promotion surface of the dust discharge assist member is adapted to be occupied by an ascending air flow. The ascending air flow is such an air flow that allows, when substances, such as dust and chemical substances, fall by gravity in air, their size to balance with air resistance so that the velocity of their fall (terminal velocity) is not higher than a predetermined level. The construction prevents the substances, such as dust and chemical substances, from falling onto the heat radiation body.