AbstractThe paper deals with the experimental investigation of heat transfer from a vertical isothermal plate mounted inside a cabinet with lateral openings. Ambient air is drawn into the cabinet and cools the plate by natural convection. The experiments were conducted by varying the distance between the plate and the cabinet walls, the plate-to-ambient temperature difference and the size, position, shape and number of the vent openings. Local and average heat transfer coefficients along the plate were measured by the schlieren optical technique. Heat transfer rates from the plate turned out to be significantly influenced by the geometric and thermal parameters investigated. The results provide a useful tool for thermal design of cooling systems by air natural ventilation.