States that current methods for calculating the building cooling loads use many approximations to account for solar radiation through a window where there is shadow from overhangs and side fins. Presents a comparison of the ASHRAE, German and Dutch standard calculation procedures with a more precise method of 'negative cooling load'. The comparisons show that the results from the above procedures differ significantly from the values of the 'negative load' method. At certain periods of the day, the difference may be as much as 50%.

KEYWORDS: Calculating, cooling load, buildings, windows, insolation, solar radiation, solar heat gain, shade, accuracy, comparing, standards, Netherlands, Germany.