Glass installed for building façade ideally possesses significant level of outdoor indoor transmission class (OITC) so it does not decrease OITC of conventional wall façade significantly. This study is about OITC of glass building in the temperature warmer than the one outlined by ASTM E-90, as it is commonly experienced in a tropical environment. Monolithic, laminated and tempered glass were tested using ASTM E-90 and calculation of OITC was conducted using ASTM E1332-90. Modification of room temperature was made to replicate warmer temperature like the temperature in a tropical environment, whilst other specifications was made based on ASTM E-90. The test showed that at higher frequency of 630 Hz and above, laminated glass performed slightly better insulation compared to monolithic and tempered but the OITC of laminated glass was dropped to 29, caused by a very sharp coincidence dip at frequency of 125 Hz which was 17 dB only. This explains that within temperature approximately 5 °C warmer than the one outlined by ASTM E-90, laminated glass used for building façade would not perform noise insulation better; it is different from many earlier studies which concluded laminated glass had better sound insulation compared to monolithic and tempered glass in term of STC and OITC.
