Alarm Sound Propagation Characteristics of Gas Extinguishing System Installed in Computer Server Room

Abstract

Gas extinguishing systems are used for fire protection in server rooms and data centers. In the fire safety standards (NFSC 106, 107) of gas extinguishing systems (carbon dioxide, halon, and clean agent extinguishing system), sound alarm devices are installed in each protected area to provide an effective warning to personnel in the protected area or areas with objects to be protected. By measuring the noise level generated in a small server room, it was found that more than 70 dB of noise was generated. Therefore, to effectively transmit alarm sound to workers in all areas within the protection area, such as a server room, an acoustic alarm device must be designed and installed so that an alarm sound is transmitted at a level of 15 dB or higher than the noise level generated by equipment installed in the facility. As a result of predicting the alarm sound through the room acoustic simulation for a small server room equipped with an acoustic alarm system in a cabinet-type gas extinguishing system, it was found that it was insufficient in effectively delivering an alarm sound to the entire protection area. To effectively transmit an alarm sound inside the protection area where a gas extinguishing system is installed, the output of the alarm device needs to be increased and the room acoustic parameters should be predicted in advance using room acoustic prediction techniques and actively adjusting the acoustics according to the noise generated inside the protection area. Additionally, the distance between alarm devices needs to be shortened to deliver sufficient alarm volume throughout the protection area, and it is necessary to establish specific standards for this.