An algorithm for choosing the number of quadrature nodes before calculation of a view factor is proposed. Simple criterion is introduced that allows one to estimate the error in the computed view factor. The algorithm allows one to save much computation time by always using the minimum number of nodes for each pair of surface zones and insures a desired accuracy. The algorithm is applied for model of a continuous furnace and is compared with a standard method which uses predefined number of nodes at each surface. The proposed algorithm is many times faster and also more accurate than the standard one.