Issue link: https://www.e-digitaleditions.com/i/1386104
58 I ICT TODAY Firestop system to be tested SOUND SOURCE ROOM SPL of sound source room SPL of sound receiving room SOUND RECEIVING ROOM Sound Level Meter (1/1 Oct...band analyzer) Sound Level Meter (1/1 Oct...band analyzer) Noise Generator Power Amplifier Loudspeaker FIGURE 8: ASTM E90 procedure for testing sound transmission performance with sound pressure level (SPL). Wall and floor assemblies can be designed to serve as sound reduction barriers to compartmentalize areas of a building, similar to the concept of fire and airflow compartmentation. To address this, ASTM E90, Standard Test Method for Laboratory Measurement of Airborne Sound Transmission Loss of Building Partitions and Elements, evaluates sound transmission performance of wall and floor assemblies reported as sound transmission class (STC) ratings. This procedure involves two sound control rooms divided by a test partition (e.g., gypsum, block wall) constructed to exact specification. One room is designated as the source and the other is designated as the receiving or terminating room as illustrated in Figure 8. A baseline STC rating of the constructed partition, without any MEP penetration openings or joint gaps, is first established. The specific materials and methods in which a barrier is constructed can significantly impact sound transmission performance. Using gypsum walls as an example, variables, such as stud material and width, type of gypsum, and use of resilient channels impact the baseline wall performance. Openings are then created in the test assembly to evaluate MEP penetrations, such as data cables. Typically, these sample penetrations are sealed with the same firestop technology used for a fire-rated assembly. The modified partition is then re-tested to evaluate the system's performance compared to the baseline. As with fire-rated barriers, openings for MEP penetrations can reduce sound impedance performance. Furthermore, data cable openings, with the need for constant re-penetration over a data center facility's life, can present a continual risk to the desired STC assembly ratings. It is important to reflect and consider all potential issues from MEP penetrations.