Influence of natural ventilation on the thermal behavior of a massive building

The aim of this paper is to evaluate the thermal behaviour of a massive building during summer period. Experimental investigations were carried out on "Caserma Gaetano Abela", an historical building located in Siracusa (Italy). The researchers have investigated the variation of both walls and indoor air temperatures in two rooms located on the east and west-facing sides. Two different experimental set-up were conducted, the first without allowing nocturnal ventilation, while the second with nocturnal ventilation obtained by opening the windows from 8:00 pm to 8:00 am. Based on the measurements of several physical parameters, the thermal lag and the decrement factor were calculated for the two ways of building ventilation management. The thermal comfort in the two offices was evaluated using the PMV and PPD indices. Results show that the high thermal inertia mass combined with natural ventilation reduces the indoor temperature during the nocturnal period, however the passive strategies resulted insufficient to obtain thermal comfort conditions during the following daytime hoursic correction. Globally it is possible to obtain an improvement of RT60 from 7.3 to 2.5 s at 1 kHz and STI increases from 33.0% to 40.0%, at 1000 Hz.