Valuation of the acoustic environment by the double skin façade for postgraduate classroom of the National Autonomous University of Mexico

The recent building for classrooms of postgraduate studies of the UNAM (2013), exceeds the international standard acoustic comfort of (35dBA), investigating it was determined that the noise entering through the façade that gives to the Insurgentes avenue does not isolate the enough noise. On the other hand, the university legislation does not allow to alter the original facades because it belongs to the cultural heritage of UNESCO-UN, to solve this problem, it was initially brainstormed, in the end two alternatives were proposed. 1°an Insulation Barrier (IB), located at the edge of the property that divide the vehicular stream and the architectural complex; 2° a Double Skin Façade (DSF), with photovoltaic glass 2 meters from the original façade, without laterals that close it. To simulate the SPL that isolates the IB, and those will have been between the original façade and the DSF, The LimA predictor program was used, the microphones values obtained in the first proposal were placed two meters from the original façade, this test was carried out in two different heights from IB, the results were that does not reduce enough, with maximum values of 5 dBA and the interior SPL is 38 dBA or greater. The second proposal, was made in two different DSF heights, the acoustics insulation values obtained by microphones that were placed onside that space are in the range of 11 to 18 dBA, based on these results the SPL inside the classroom are in the range of 28 to 35 dBA, so now it meets acoustic comfort. Analyzing the values obtained with the simulator, we can say that they are probable. Additionally, consider in the urban landscape sustainable building with DSF.