SHGC measures which of the following?

• A. The ratio showing the sun's heat that passes through the product
• B. The ratio of heat loss through the roof
• C. A measure of reflectivity
• D. A measure of noise reduction

Answer: (A)

SHGC is the measure of how much solar energy from the sun actually becomes heat inside the building through the glazing. It’s expressed as a ratio: the portion of incident solar radiation that is transmitted through the glazing as heat inside the space divided by the total solar radiation hitting the surface. So the best choice describes the sun’s heat that passes through the product. This isn’t about heat loss through the roof (that’s a different metric related to insulation and U-factor), nor is it a measure of reflectivity or noise reduction. SHGC values range from 0 to 1, with lower values reducing cooling loads and higher values allowing more solar heat gain.