Which option correctly lists a pair of passive cooling strategies?

• A. Active cooling with air conditioning
• B. Night ventilation (night flushing) and natural ventilation with shading
• C. Use of high-efficiency boilers
• D. Solar shading only

Answer: (B)

Passive cooling relies on natural processes to reduce indoor temperatures without using energy-intensive equipment. Night ventilation, or night flushing, uses cooler outdoor air at night to replace the warmer indoor air, helping to remove heat stored in the building mass and lowering temperatures without fans or air conditioning. Natural ventilation with shading combines openings that let air flow through the space with shading devices that block or reduce solar heat gain during the day. By letting cool air in at night and minimizing heat gain during the day, this pair achieves cooling through everyday environmental conditions rather than mechanical systems.

Active cooling with air conditioning is energy-intensive and not a passive approach. High-efficiency boilers focus on heating rather than cooling. Solar shading alone reduces heat gain but doesn’t provide the airflow-based cooling that night flushing adds, so it isn’t a complete passive cooling pair on its own.