Which statement best describes a passive solar heating approach in buildings?

Which statement best describes a passive solar heating approach in buildings?

• A. It uses photovoltaic cells to convert sunlight into electricity
• B. It relies on wind-driven collectors
• C. Absorbs heat directly from the sun without mechanical equipment to collect and store energy
• D. It heats water with solar thermal collectors and pumps

Answer: (C)

Passive solar heating relies on designing the building to capture and store heat from the sun without using pumps, fans, or other mechanical devices to collect or move that heat. The sun warms the space directly through appropriately placed windows, and materials with high thermal mass—like concrete or brick—absorb heat during sunlit hours and slowly release it as it cools, helping to maintain a comfortable indoors with minimal energy input. This approach also relies on proper insulation, shading for summer, and thoughtful orientation to maximize winter sun exposure. The statement describing absorbing heat directly from the sun without mechanical equipment to collect and store energy captures this idea exactly, which is why it’s the best description. Other options involve converting sunlight to electricity, using wind-driven collectors, or heating water with solar collectors and pumps—these are active solar techniques that rely on moving parts or external energy to collect or transport heat.

Passive solar heating relies on designing the building to capture and store heat from the sun without using pumps, fans, or other mechanical devices to collect or move that heat. The sun warms the space directly through appropriately placed windows, and materials with high thermal mass—like concrete or brick—absorb heat during sunlit hours and slowly release it as it cools, helping to maintain a comfortable indoors with minimal energy input. This approach also relies on proper insulation, shading for summer, and thoughtful orientation to maximize winter sun exposure.

The statement describing absorbing heat directly from the sun without mechanical equipment to collect and store energy captures this idea exactly, which is why it’s the best description. Other options involve converting sunlight to electricity, using wind-driven collectors, or heating water with solar collectors and pumps—these are active solar techniques that rely on moving parts or external energy to collect or transport heat.