Abstract:
Abstract Most office buildings are designed to be ventilated and cooled using
mechanical systems. In a temperate climate, when the outdoor temperatures are
favorable, e.g. at night, passive ventilation and cooling techniques can be used to
reduce energy consumption. Building’s thermal mass represents a way to accomplish
that goal due to their ability to retain and dissipate heat. However, the portion of
exposed elements in modern constructions is kept to a minimum. There are decorative
components, like the suspended ceiling, that represent an insulation between the
internal occupation zone and the thermal elements, preventing the desired thermal
exchange. In this work, an innovative solution that optimizes the night cooling
phenomena is presented. It is concerned with the use of the plenum formed by the space
between the slab and the suspended ceiling for cooling purposes. Computational Fluid
Dynamics (CFD) simulations were performed and the predictions validated by the
experimental results. The tests were carried on a reduced scale model based on
dimensional analysis and similitude criteria. The suspended ceilings used in the
experiments allow the outside air to cool the slab, therefore promot ing an increase of
the heat exchanged between the structural elements of the building and the zone that
needs to be cooled. The results indicate that the increased amount of exposed slab area
contributes to lower the day peak indoor temperatures.