World Ventilation Day 2026 will focus on overheating in buildings and the role of ventilation and cooling strategies, according to the Building Engineering Services Association (BESA). The fifth edition of the international awareness campaign will examine approaches including ventilative and evaporative cooling, passive design and intelligent ventilation alongside growing demand for air conditioning.
BESA will host a World Ventil8 Day Exchange at the Building Centre in London, UK, on November 5, with Mitsubishi Electric Living Environmental Systems UK as sponsor and CIBSE as official partner. The programme will bring together engineers, contractors, consultants, housing professionals, policy makers and industry leaders.
Sessions will cover Smart Ventilation and Emerging Technology, including the use of AI tools for indoor air quality monitoring and ventilation performance assessment. Other topics include standards and guides DW145, TR19 and DW154, the whole-life cost of ventilation improvements, business cases for retrofitting systems, and mould and damp in social housing.
BESA and CIBSE will also support the wider World Ventilation Day initiative, with events organised by international partners including AREA, ASHRAE and UNEP. The campaign was created by a coalition of scientists, academics, engineering bodies and environmental activists to promote ventilation’s role in health, well-being and productivity.
“This year’s heatwaves prompted a sudden surge in demand for retrofit air conditioning, but the risk is that we go from living in airtight boxes to airtight boxes with cooling,” said Adam Taylor, chair of BESA’s Indoor Air Quality group and managing director of ARM Environments. “There are lots of low energy solutions that should be adopted before we resort to mechanical cooling systems and we will be looking at these in detail at this year’s World Ventil8 Day Exchange.”
