Stack ventilation is a natural cooling method that uses the principle of warm air rising. In a building, warm air inside becomes less dense and rises, creating a pressure difference. This allows cooler air from outside to enter through lower openings, promoting airflow and reducing indoor temperatures. This technique is often used in green buildings and sustainable architecture to enhance energy efficiency. By strategically placing vents and openings, stack ventilation can improve indoor air quality and reduce reliance on mechanical cooling systems, leading to lower energy consumption and costs.