Durability of humidity-based ventilation components after 15 years of operation in French residential buildings – Lab tests

Humidity-based DCV systems have been widely used in France for 35 years and are considered as a reference system, including for low-energy residential buildings. The on-going Performance 2 project delivers the new results of a thirteen-year monitoring in twenty-two social housing apartments. The involved consortium is composed of Cerema, Univ. Savoie Mont Blanc and two industrials partners: Aereco and Anjos. 
The initial project was a large-scale monitoring on thirty new occupied apartments equipped with this DCV system, which extended from 2007 to 2009. The equipment included IAQ sensors in different rooms of each dwelling (temperature, humidity, and CO2), as well as pressure and volume flow sensors for monitoring the ventilation system. Recordings were performed every minute over two years. This former study showed: The good IAQ in terms of CO2 and humidity, a good correlation between CO2 and airflows, savings on heat losses of 30 % in average compared to regulatory constant airflows. 
Thirteen years later the building is re-visited, and the monitoring system is turned back on with the intention to assess the ventilation system performance after a prolonged in-situ functioning period.  
Then, the components have been collected and tested in laboratory facilities, before and after cleaning, and then after light rehabilitation. In this article, we give the results of these data about the durability of ventilation components.   
In the context of the increasing awareness about smart ventilation, these feedbacks highlight as a crucial issue, the durability of the ventilation systems and its components (including the sensors) and their robustness to a lack of maintenance or even a bad use by occupants.