Which of the following is currently the most recommended water system for a computer room?
Correct Answer: A
Explanation/Reference:
Explanation:
Preaction systems are similar to dry pipe systems in that the water is not held in the pipes, but is released when the pressurized air within the pipes is reduced. Once this happens, the pipes are filled with water, but it is not released right away. A thermal-fusible link on the sprinkler head has to melt before the water is released. The purpose of combining these two techniques is to give people more time to respond to false alarms or to small fires that can be handled by other means. Putting out a small fire with a handheld extinguisher is better than losing a lot of electrical equipment to water damage. These systems are usually used only in data processing environments rather than the whole building, because of the higher cost of these types of systems.
Incorrect Answers:
B: Wet pipe systems always contain water in the pipes and are usually discharged by temperature control- level sensors. This type is not the most recommended water system for a computer room. Therefore, this answer is incorrect.
C: In dry pipe systems, the water is not actually held in the pipes. The water is contained in a "holding tank" until it is released. This type is not the MOST recommended water system for a computer room. Therefore, this answer is incorrect.
D: A deluge system has its sprinkler heads wide open to allow a larger volume of water to be released in a shorter period. Because the water being released is in such large volumes, these systems are usually not used in data processing environments. This type is not the most recommended water system for a computer room. Therefore, this answer is incorrect.
References:
Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, 2013, p. 474-475