Built environment & energy efficiency
Natural Ventilation
Definition
Natural ventilation uses natural forces — wind pressure differences and thermal buoyancy (the stack effect) — to deliver fresh air into buildings through strategically placed openings such as windows, louvres and roof vents. Wind-driven flow exploits pressure differences across a facade; buoyancy-driven flow uses the tendency of warm indoor air to rise and escape through high openings, drawing cooler air in below.
References
Supports definition and framing.
Supports definition and framing.
Overview
What it means
Before mechanical systems, all buildings were ventilated this way. Properly designed passive systems are self-regulating and can include night cooling, where ventilation purges heat absorbed by the building's thermal mass. Poorly designed ones fail — airflow, noise, security and pollution must all be resolved.
How it is used
Passive and mixed-mode ventilation feature in green building design and energy codes; operable facades and atria are designed around stack and cross-ventilation principles.
Why it matters
Cooling is among the fastest-growing energy demands in buildings; natural ventilation offers comfort with little or no operational energy — passive design at its most direct.