In tropical climates, which glazing property is desirable to balance daylight with heat gain?

• A. High SHGC
• B. Low solar heat gain coefficient (SHGC)
• C. No UV protection
• D. No tinting

Answer: (B)

In tropical climates, the key glazing property to balance daylight with heat gain is the solar heat gain coefficient, and you want it low. SHGC measures how much solar radiation through the glass becomes heat inside the space. A low SHGC means less heat enters from the sun, which helps keep interiors cooler and reduces cooling loads, while still allowing daylight to come in if the glass has adequate visible transmittance. This balance is crucial when cooling dominates the energy use. High SHGC would bring in more solar heat, making cooling harder; extra UV protection or no tinting don’t directly address heat gain, and simply not tinting generally increases heat and glare. So, choosing glazing with a low SHGC achieves daylighting with minimal heat gain.