Which glazing strategies help reduce heat gain in tropical buildings?

• A. Low-solar-gain glazing, double or triple glazing with gas fills, external shading such as louvers, and high reflectance coatings on glass.
• B. Single-pane clear glass with no shading.
• C. Heavy metal plates as glazing.
• D. Dark reflectance coatings to maximize absorption.

Answer: (A)

Minimizing heat gain through glazing in tropical climates focuses on reducing the amount of solar energy that enters and improving insulation. Low-solar-gain glazing limits how much solar radiation is transmitted, so less heat makes it indoors. Using double or triple glazing with gas fills increases the insulating resistance, reducing heat transfer through the glass. External shading, such as louvers, blocks a large portion of direct sun before it reaches the glass, which is especially effective when the sun is high. High reflectance coatings bounce a large portion of incoming solar energy away, keeping more heat from being absorbed.

In contrast, using single-pane clear glass with no shading allows a lot of solar energy to pass in, causing high heat gain. Heavy metal plates as glazing are impractical and don’t address heat transfer or daylight effectively. Dark reflectance coatings absorb solar energy, turning it into heat inside the building, which increases interior temperatures.