Instrumentation and Simulation of the Hygro-Thermal Conditions of a Green Building: A Study of the Impact of the Post-Occupancy Usages on Thermal Comfort

Post-occupancy evaluations (POEs) are useful for evaluating the success of any building design, but are particularly useful in evaluating green buildings. It is the only opportunity architects and engineers have to learn if their buildings actually work as planned. On the other hand, following the “guidebook” of a green building, i.e. having occupants aware of the particularity of the premise and taught about how it works and what the proper usages are (which are not automatically straightforward), is of prime importance since misuse of a green building can directly lead to discomfort and energy over consumption. In that framework, this paper stresses the link between occupants’ usages and their indoor thermal comfort by attempting a quantification of the impact of each usage on indoor temperature and hygrometry (and thus thermal comfort), showing by the way that, in order a POE to fully give exploitable results, a communication to occupants on proper usages has to be the first step after the delivery of a green building. To study that link, the real case of a green building located in the French tropical island of La Re´union has been used. The overall idea followed in this work lies in two steps: The first one is the creation of a “validated” digital building description obtained thanks to a process of comparison between simulations outputs (DesignBuilder) and field measurements (weather and comfort stations), and to a “block by block” approach that allows independent validations of the description of the fabrics and of the description of the usages. The second step is the utilization of the model obtained in the first step to perform simulations of new usages, as modifications in natural ventilation features (doors, windows open or closed) or in number of occupants, lighting schedule etc. These new simulations lead to the possibilities of comparing situations between each others, and therefore of quantifying the contribution, positive or negative, of each chosen usage to thermal comfort. Eventually, this paper will describe an example of combination of new usages that makes the conditions noticeably more comfortable within the building, stressing that following the good usages in a green building is a first requirement before realizing any POE.