This report summarizes the structure and the outcomes of Annex 80 – Resilient Cooling of Build-ings, which was conducted as a five-year international research project within the IEA Technical Collaboration Programme EBC – Energy in Buildings and Communities.  

The world is facing a rapid increase of cooling of buildings. This is driven by multiple factors,  such as urbanization and densification, climate change, power shortage, and elevated comfort expectations as well as economic growth, especially in hot and densely populated regions of  the world. The trend towards cooling seems inexorable. It is mandatory to guide this  development towards sustainable solutions.  

This midterm report sums up the developments of Annex 80 between October 2019 and July 2021. Commencing with an initial Expert Meeting held in person in Vienna, Austria, subsequent work efforts by the Operating Agent (OA) and its team included conference calls and the second through fourth Expert Meetings which were held online due to the COVID-19 pandemic. 75 participants from 17 countries and 36 institutions actively took part in the fourth Expert Meeting. 22 institutions confirmed their participation with official letters in the first half of the Annex working phase. 

The world is facing a rapid increase of air conditioning of buildings. This is being driven by multiple factors, such as urbanization and densification, climate change and elevated comfort expectations as well as economic growth in hot and densely populated regions of the world. The trend toward cooling seems inexorable. It is imperative to steer this development towards sustainable solutions. 

This IEA Annex 80 Subtask C report and the associated brochures provide examples of well-documented field studies. These field studies apply resilient cooling technologies to reduce energy demand and carbon emissions for cooling and reduce the overheating risk in different types of buildings, including newly constructed and existing buildings. Examples and details on building information, energy systems, resilient cooling technologies, key performance indicators (KPIs), and performance evaluation and lessons learned are included in the report and the brochures.

This report summarizes an assessment of current State-of-the Art resilient cooling strategies and technologies. It is a result of a collaborative work conducted by participants members of IEA EBC Annex 80. This report consists of four chapters.

The current trend in most Western countries regarding building ventilation is to follow the “build tight, ventilate right” strategy. New energy efficient buildings are indeed getting more and more airtight to avoid energy losses through uncontrolled air leakages. Instead of relying on natural infiltration, ventilation systems are installed to ensure a good indoor air quality (IAQ) with controlled ventilative air flowrates.