Durability of humidity-based ventilation components after 13 years of operation in French residential buildings – Assessment of components performance in laboratory

Abstract

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 feedback from 13 years of on-site operation in twenty-two social housing apartments. The initial project was a large-scale monitoring on thirty new occupied apartments in two buildings in France equipped with this DCV system, which extended from 2007 to 2009. Thirteen years later the buildings are 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: as collected, after cleaning, and finally after a light rehabilitation. Despite largely insufficient levels of maintenance, 100 % of the exhaust units and air inlets not purposely degraded by the occupant, still reacted as expected to humidity. A good relationship was found between the visual maintenance level and the limitation of maximum airflow for each Air Terminal Device (ATD): an average limitation of −10.6 m3/h has been evaluated for ATDs presenting a “Bad” level of maintenance whereas the average limitation was only −2.2 m3/h for ATDs showing a “Good” maintenance state. Finally, after cleaning and refurbishing, but without touching the hygroscopic sensor/actuator, the ATDs still meet the specifications and are very close to their original characteristics.