Freevent : ventilative cooling and summer comfort in 9 buildings in France

Recent studies have shown that ventilative cooling reduces overheating, improves summer comfort and decreases cooling loads. Therefore, it is considered as one of the most efficient way to improve summer comfort. Although, HVAC designers still lack of guidelines to improve the energy and comfort efficiency of their installations.  
This paper is issued from the research project FREEVENT that mainly deals with field measurement evaluations of summer comfort and evaluates the efficiency of ventilative cooling in French residential and office buildings. The objective of this work is to quantify and qualify the efficiency of the ventilation systems and the energy and thermal performance of buildings. For this, two field measurement campaigns were conducted: ventilation checks on 9 sites and full measurements and monitoring on 6 of them.  
We present the results of FREEVENT project, including state of the art and onsite measurement campaigns. Onsite conditions, buildings’ architecture characteristics, thermal inertia, solar shadings and various constraints are discussed as main designing choices for efficient ventilative cooling systems. We show how performance is linked to good sizing, design, correct use of thermal destocking, and - last but not least - correct fit in and correct take over, checking airflows as well as controls of the system. 
Our study concludes with recommendations guidelines for designers, published in a French guide.