Ventilation is at the nexus of health, energy and climate. Adequate ventilation in buildings and cities is essential for human health, comfort and performance, and the approach to achieving this can have an enormous impact on building energy consumption, carbon emissions and climate change. The field of ventilation intersects with many closely related fields including indoor air quality, HVAC systems design and operation, public health, building materials and envelope systems, architectural design and urban planning, and environmental control in transportation vehicles, industrial and agricultural production facilities.International Journal of Ventilation (IJV) is a peer reviewed journal dedicated to serving the international scientific community of ventilation. IJV publishes high quality original research works that have potentially long-lasting value and significant impact on the advancement of ventilation theory and/or practice. Both the fundamental theory and practice are emphasized here. Theory enables us to establish generalizable principles for broader applications. Practice validates theory and inspires new research and development.