In recent decades, there has been a consistent rise in global temperatures, coinciding with the accelerating progression of climate change. The increasing number of heat days is affecting not only the outdoor environment but also indoor temperatures in buildings in European cities, creating a difficult situation.
The risk of overheating, is already clearly evident during not only the summer, but also in transitional periods as a result of the climate change-induced temperature rise. Free cooling (e.g. ventilative cooling) is a much-needed solution that can be used both during day and night. Night cooling through window openings in combination with appropriate thermal mass has been reported as an extremely energy-efficient measure in many locations for preventing or minimizing overheating in buildings.
The aim of the CoolBRICK project was to evaluate the cooling potential, with normative calculation procedures for (passive) ventilative night cooling strategies in spaces with different types of natural ventilation strategies (single-sided, cross and stack -ventilation), window control strategies (e.g. model predictive control), and thermal masses. Results of a long-term monitoring campaign on two identical buildings in Salzburg, Austria, which included detailed measurements of the thermal environment and air change rates, based on the constant emission tracer gas method, will be presented.
The results indicated a greater potential for ventilative cooling than current standards prescribe. These findings highlight the need for updated design standards that can use natural ventilative cooling as a nearly zero-energy and resilient solution for climate adaptation in buildings. COOLBrick and new international projects on free cooling have been initiated by international standardisation bodies (e.g. CEN, ISO) and at a national level, describing newly developed evaluation, calculation methods and design guidance for ventilative cooling to support designers in creating resilient, future-proof cooling systems for buildings and further promote the use of night cooling.