Caisse Allocation Familiale

Saint-Denis 2013

IES Consulting works in partnership with BATEG on the comfort study for the future offices of the family allowance fund (Caisse d’Allocations Familiales – CAF) in Saint-Denis

Key Facts

  • Comfort Study
  • Used Thermal Stimulation Software
  • Project Partners: BATEG

IES Consulting is working in partnership with BATEG on the comfort study for the future offices of the family allowance fund (Caisse d’Allocations Familiales – CAF) in Saint-Denis. This study was prepared using the “Virtual Environment” (VE) dynamic thermal simulation software developed by IES.

The aim of the study is to evaluate the indoor comfort of buildings during the summer using a dynamic thermal simulation. This involves a time study of the energetic performance, conducted over a typical year. Operational and usage attributes of the future building, e.g. occupation, lighting and ventilation, are the subject of scenarios defined to best approximate reality.

The building envelope has been modelled according to the project characteristics so as to take the insulation, thermal inertia, conductive exchanges and solar thermal contribution into account. Solar shading and protection are considered through simulation with the Suncast module.

Natural ventilation by opening windows is modelled using the MacroFlo module. The opening and closing of windows depends not only on the indoor but also on the outdoor climatic conditions. MacroFlo is a tool for the analysis of air flow across a surface in terms of the temperature gradient and pressure on either side of the surface. It takes the wind direction and speed into account.

During office occupation, a scenario of the windows being opened by users (approx. 40% open) was considered so as to determine the impact of natural ventilation on the indoor comfort.

Several scenarios were investigated to demonstrate the optimal configuration for indoor comfort without having to resort to an air conditioning system. Dual-flow ventilation with cooling of the hygienic blown air is foreseen as the basis. The simulations then consider the natural ventilation by opening windows and nocturnal “free cooling”.