Abstract
1. In order to calculate the quantity of natural ventilation caused by the ventilator which equipped in construction (see Fig. 1), the following equation should be used as practical. [table] where [table] and [numerical formula] where P_0; wind pressur on vetilator head, kg/m^2 C_<0s>; coefficient of static wind pressure at ventilator head C_<0d>; coefficient of dynamic wind pressure on ventirator head α; wind velocity radio [numerical formula]; pressure loss of vetilator entrance & elbow, kg/m^2 [numerical formula]; pressure loss of straight part of ventilator, kg/m^2 ζ_v; loss coefficient of ventilator head v; wind velocity in ventlator P_i, C_i, ζ_i,V_i; see another report. 2. As for the loss coefficient of ventilator head, following equation is explained. [table] and [table] where P_s: static pressure at ventilator neck, kg/m^2 P_0: total wind pressure at ventilator neck when air move in ventilator is stopped, kg/m^2 V_v: wind velocity near the ventilator head, m/s θ_x: vertical wind direction at ventilator head. The relation between the v/V, θ_x and ζ_v about many kinds ventilator which show Fig. 2 are ilustlated in Fig. 4〜13.
