=+8-39. Determine the solar heat gain for an 8 ft wide, 4 ft high, nonoperable triple-pane window with a white vinyl frame, 2.5 in. in width, for 3:00 p.M. on July 21 in Boise. ID. The glazing is Type 29a from Table 7-3. The frame is aluminum-clad wood with insulated spacers.