Assessment Of The Performance Of Hybrid Ventilation System: Case Study Of A Multi-family Building In France

By using natural driving forces, hybrid ventilation systems reduce fan energy consumption in buildings. They are of increasing interest as they help to improve buildings energy efficiency while ensuring good indoor environmental quality. However, the performance of these systems is variable and dependent on climatic conditions. Besides, the plurality of openings, variable airflows, and unstable flow patterns make the measurement of the performance of natural or hybrid ventilation systems a challenging task. Therefore, their implementation in new residential buildings, in France, is restricted by regulatory constraints that impose global and permanent air exchange throughout the dwelling using minimum airflow rates. The development of a reliable method to assess the real performance of natural (stack effect) or hybrid ventilation systems can help to promote the use of these systems. This is the objective of the research project VNAT (2017-2021). During this project, we carried out an in situ assessment of the indoor environmental quality of a multi-family apartment building equipped with a hybrid ventilation system. The building was monitored between December 2018 and April 2019. It is located in Lyon. It was constructed in the 1950s, and was retrofitted in 2014 by adding a fan-assisted hybrid ventilation system. The paper presents first the building and the ventilation system followed by the measurement method. It presents second the results regarding the operation of the ventilation system and the indoor environmental quality in the apartments. Results from this paper will help to build a protocol dedicated to the assessment of the performance of hybrid or natural (stack effect) ventilation systems under real conditions.