A low SHGC would best reduce what?

• A. Solar heat entering the interior through glazing
• B. Heat loss through opaque walls
• C. Wind infiltration
• D. Acoustic transmission

Answer: (A)

The main idea is how glazing properties affect solar heat gain. SHGC, or Solar Heat Gain Coefficient, measures the fraction of solar radiation that passes through window glazing and becomes interior heat. A low SHGC means less solar heat gets into the building from sunlight, so it best reduces solar heat entering the interior through glazing. It doesn’t directly affect heat loss through opaque walls, wind infiltration, or acoustic transmission, which are governed by insulation and air sealing, and by sound transmission properties, respectively.