IEA EBC Annex 62: Ventilative Cooling

The main goal of the Annex 62 is to make ventilative cooling an attractive and energy efficient cooling solution to avoid overheating in buildings. Ventilation is already present in buildings through mechanical and/or natural systems and it can remove excess heat gains as well as increase air velocities to widen the thermal comfort range. The results from the Annex facilitate better possibilities for both design purposes and for energy performance calculation.

Short Description

The project started off with the „State of the Art Review (SOTAR)" composed by the international Annex 62 consortium. Peter Holzer from Austria contributed to the chapter „Existing Components and Control Strategies for Ventilative Cooling". The report has been published on the Annex 62 platform

The following evaluation of the theoretical functionality of ventilative cooling in Austria showed substantial potential for residential as well as office buildings and with increasing cooling needs an even greater benefit from ventilative cooling systems.
For the evaluation of practical implementations a database of buildings using one or several elements for ventilative cooling has been set up. The database's structure follows the chapter 5 of the SOTAR and has been extended by the other participating countries in the course of the project.

Based on the findings from these evaluations several buildings using ventilative cooling in Vienna and Linz have been investigated. From the user's experiences in-depth insights concerning requirements, usage and user acceptance have been obtained.

Three buildings have then been chosen to investigate over the course of several days during a hot summer period. Using temperature loggers and a hot wire anemometer the actual cooling performance of the implemented ventilative cooling system have been evaluated.

The results showed that mechanical systems reached cooling loads of 15-25 kWh/m²NFa and very good energy efficiency ratios (EER). The highest EER value found was 24. Ventilators with low energy consumption, the well-chosen size of air inlets (automatic operated bottom hung windows) and the low pressure drop of the on-roof ventilations ducts made this EER possible.

Two long term monitorings have also been carried out in the meantime investigating the ventilative cooling systems of the office building of Windkraft Simonsfeld AG in Lower Austria and a department building of the University of Innsbruck in Tyrol. The results have been reported and will be published in "Case Study Brochures" internationally.

Finally the national project concluded with the composition of an Austrian guidebook for ventilative cooling, which informs decision-making in early design phases and helps implementing ventilative cooling systems. Hands-on predimensioning rules as well as decisive preconditions are also stated in the guide.


Austria, Belgium, China, Denmark, Finland, Italy, Ireland, Japan, Netherlands, Norway, Portugal, Switzerland, UK, USA

Contact Address

Institute of Building Research & Innovation
DI Dr. Peter Holzer
Wipplingerstraße 23, 1010 Vienna