Which statement correctly distinguishes active solar heating from passive solar design?

Which statement correctly distinguishes active solar heating from passive solar design?

• A. Active uses mechanical systems to move heat; passive uses building design to collect/store heat without moving parts.
• B. Active relies on building orientation; passive uses collectors.
• C. Active uses windows only; passive uses mechanical pumps.
• D. Active stores heat in phase-change materials; passive uses natural ventilation.

Answer: (A)

Main idea: The difference between active solar heating and passive solar design is whether heat is moved with mechanical devices or managed through building design and materials without moving parts. Active solar heating uses mechanical systems to collect solar energy and then move that heat where it’s needed—think solar collectors that heat a fluid, pumps or fans circulating that fluid, and a storage tank or heat exchanger to distribute warmth to living spaces. Passive solar design, by contrast, relies on the building’s orientation, window placement, materials with high thermal mass, insulation, and shading to collect, store, and distribute heat without any moving parts or external pumps. So the statement is best because it correctly pairs active with the use of mechanical systems to transport heat and passive with architectural design that captures and retains heat without moving components. The other options mix up where collecting and moving heat occur or imply mechanisms (like relying on windows or ventilation as defining features) that aren’t the essential distinction.

Main idea: The difference between active solar heating and passive solar design is whether heat is moved with mechanical devices or managed through building design and materials without moving parts.

Active solar heating uses mechanical systems to collect solar energy and then move that heat where it’s needed—think solar collectors that heat a fluid, pumps or fans circulating that fluid, and a storage tank or heat exchanger to distribute warmth to living spaces. Passive solar design, by contrast, relies on the building’s orientation, window placement, materials with high thermal mass, insulation, and shading to collect, store, and distribute heat without any moving parts or external pumps.

So the statement is best because it correctly pairs active with the use of mechanical systems to transport heat and passive with architectural design that captures and retains heat without moving components. The other options mix up where collecting and moving heat occur or imply mechanisms (like relying on windows or ventilation as defining features) that aren’t the essential distinction.