Analysis of Energy Flexibility and Indoor Air Quality of The GreEn-ER Building

This internship aims to analyse the impact of energy flexibility on indoor air quality, in response to modifications made to the default pressure set-points of air handling units(AHUs) in the GreEn-ER building in Grenoble, France. The building incorporates advanced HVAC systems, natural ventilation, and energy-recovery features, making it a suitable case study for energy flexibility research.

The experiment conducted for this internship (denoted neo-Flex) builds on key ideas from a previous experiment conducted in the same GEn-ER building (denoted CUBEFLEX), but introduces a new series of controlled interventions on selected AHUs (locally called CTAs). During the neo-Flex experiment, the supply and return pressure set-points of CTAs were reduced by 25% or 50% for four-hour periods on selected days when the building met our occupancy criteria.

Energy performance on these selected days was analysed by studying the electrical consumption data of the building, while indoor air quality and occupant comfort were analysed by studying the CO~2 concentration data. Occupancy and window/door status were monitored manually to provide context.

The results show that reducing CTA pressure set-points can lower electrical consumption without appreciably degrading indoor air quality when the reduction is limited to 25%. At a 50% reduction of pressure setpoints of AHUs, some rooms experienced elevated CO~2 levels but generally remained within acceptable occupant comfort limits. These findings confirm and extend the trends observed during CUBEFlex and illustrate the potential for controlled ventilation flexibility in tertiary buildings.