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ENGINEERED POWER SOLUTIONS 72 SOUTH MAIN STREET, SUITE A TEMPLETON, CA 93465 Solar Warehouse Rail Analysis – Generic Packet 3.3 – Wind Forces Per Section 29.4.4, the wind velocity pressure is determined by Equation Eq. 29.4-7: o p = qh(GCp)(ɣE)(ɣa) (psf) Where qh, the velocity pressure evaluated at height h, is given by Section 26.10 and Equation 26.10-1: o qh = 0.00256KzKztKdKeV2 (ASCE 7-16) ▪ Kz = Velocity Pressure Exposure Coefficient per Table 26.10-1 • Exposure B: 0.70 (h < 30ft.) • Exposure C 0.98 (h < 30ft.) ▪ Kzt = Topographic Factor per Section 26.8.2 • This packet assumes no topographic factor (Kzt = 1.00) ▪ Kd = Wind Directionality Factor per Section 26.6 • 0.85 ▪ Ke = Ground Elevation Factor per Section 26.9 • This packet conservatively uses 1.00 per note 1 of Table 26.9-1 ▪ V = 3 Second Gust Wind Speed per Section 26.5 o GCp is the external pressure coefficient given in Figures 30.3-2A-I. o The GCpf Coefficients are broken up by roof tilt and building surface location (zones). Each zone has an associated worst-case uplift coefficient as well as a worst-case downward coefficient (discussed in more detail later in this packet). The coefficient varies based on the effective wind area of the element being considered for design. The rail span summary tables in this packet assumed an effective wind area for the rails based on the continuous rails supporting a minimum of (5) modules. As noted in the tables, the listed spans shall be reduced by 1 ft. for continuous rails supporting less than (5) modules. o ɣE – Array Edge Factor as defined in Fig. 29.4-7. This packet conservatively uses 1.5 for the array edge factor for all conditions. o ɣa – Solar Panel Pressure Equalization Factor per Figure 29.4-8. o Like the GCp factor, ɣa has been calculated based on the effective wind area of the rail. Page 67 2004 W Picasso - 2018062008/29/23