Which daylighting strategy helps reduce solar heat gain while maintaining light?

• A. No shading devices
• B. Direct glass on all facades
• C. Diffusers or light shelves
• D. Opaque walls

Answer: (C)

The main idea is using daylighting strategies that shape how light enters a space so you get adequate illumination without bringing in excessive heat. Diffusers spread incoming light more evenly, reducing glare and hotspots, while also limiting the amount of direct sun that pours in. Light shelves bounce daylight off the ceiling, pushing light deeper into the room and away from the direct sun on the lower zone, which lowers solar heat gain while keeping the space well lit. Together, these approaches maintain bright interiors with less cooling demand.

Contrast that with no shading devices, which let in unmitigated sunlight and heat; direct glass on all facades, which admits a lot of solar radiation and glare; and opaque walls, which block daylight altogether.