Chapter 12: Fire Protection Flashcards
Clean Agent
An electronically nonconductive, volatile, or gaseous fire extinguisher that does not leave a residue upon evaporation.
Clean Agent Fire Suppression
A fire extinguishing system using a total flooding clean agent.
Ionization-type Detectors
These detectors have a small amount of radioactive material between the two electronically charged plates, which ionizes the air and causes current to flow between the plates. When smoke enters the chamber, it disrupts the flow of ions, thus reducing the flow of current and activating the alarm.
Photoelectric-type Detectors
These detectors aim a light source into a sensing chamber at an angle away from the sensor. Smoke enters the chamber reflecting light onto the light sensor, triggering the alarm.
Plenum
A compartment or chamber that forms part of the air distribution center.
What type of sprinkler heads shall be used for suspended ceilings?
Flush-mount pendant type
What is the minimum fire rating for a battery room?
1-hour rating, slab-to-slab
Which gas should not be used above the access floor in computer rooms?
Carbon dioxide
What are the different places in a data center with aisle containment where fire detection might be installed?
- Area monitoring within the containment
- Monitoring at transfer grilles to plenum
- Monitoring at the plenum at the return air collection point and prior to entry into the HVAC system.
- Monitoring at HVAC supply
- Monitoring at supply plenum exit points into containment.
- Area monitoring at the ceiling
- In-cabinet monitoring
What is the typical temperature range in a contained hot aisle?
From over 38 degrees C (100 F) to as high as 60 degrees C (140 F)
What is the air exchange rate in data centers?
The exchange rate can be as high as 500 to 1000 ACH in data centers - especially in contained aisles.
What are the requirements with which smoke detector spacing shall comply?
Shall comply with regulatory and code requirements and NFPA 72 or ISO 7420.
What are ionization type detectors designed for?
They are designed to be installed in areas of low air velocity and are not recommended for computer rooms.
What are photoelectric type detectors designed for?
They are designed to be installed in areas of higher air velocity.
At what temperature are dry pipe systems used?
Dry pipe systems are typically not used unless the dry range of ambient temperatures reaches below 4 degrees C (40 F)
Which sprinkler system shall not be used in the computer room or generator areas of a data center?
Dry sprinkler systems
What is recommended in areas where maximum fire protection is required?
Early warning signs or incipient-type systems be installed at selected computer room and entrance room locations.
What is the recommended detection system for each of the four data center spaces named below?
- Computer room
- Office
- Access floors
- Generator rooms
- Computer room - Early warning signs or incipient-type systems
- Office - Ionization/ photoelectric
- Access floors - photoelectric
- Generator rooms - Thermal or flame detectors
What are the three broad types of fire suppression systems?
- Wet sprinkler systems
- Gaseous fire suppression systems
- Oxygen depletion systems
What is the recommendation for clean agent systems maintenance?
Clean agent systems should be maintained in accordance with the manufacturer’s instructions and either NFPA 2001 or ISO 14520.
Which clean agent gaseous system shall not be installed in new data centers and not introduced or expanded within existing data centers?
Halon 1301 systems
What are three considerations to keep in mind when installing clean agent systems in contained spaces?
- Additional volumetric space constructed for contained closed-loop air.
- Concentration of gaseous agents
- Placement of clean agents
How many times should a pre-action sprinkler be trip tested?
At least once every three years.
What are the design requirements for smoke detector spacing?
Shall comply with regulatory and code requirements and NFPA 72 or ISO 7420.
What is the basic fire suppression system required in a computer room?
A fire sprinkler pre-action system.
Under what conditions can you waive the modifications for water sprinklers or gaseous suppression systems in contained spaces?
Modifications may be waived if:
1. Obstructions are removable prior to an emergency dispersal event
2. Obstruction can be removed without compromising means of egress, and
3. Removal is initiated by an automatic means of smoke detection.
In what direction shall the hinged doors used in hot aisles open?
Egress
What shall be provided if pass-throughs or windows are provided in the fire-rated walls of a computer room?
Such openings shall be provided with a fire-rated shutter or fire-rated window of a rating equal to the wall.
Fire alarm systems can be classified into three types. List them.
- Protected premises
- Supervising station
- Household fire
What is a protected premise fire alarm system?
A single fire alarm system. In this case, the system is contained to the entire campus or a single building; it is under common ownership and use.
What is a supervised station alarm system?
This system embellishes on a protected premises system and is continuously monitored by a central monitoring entity for any abnormal events. The central monitoring entity is responsible for dispatching, reporting, or similar functions in response to alarm initiation.
Dry sprinkler systems are prohibited from what specific areas of the data center?
The computer room and generator areas
It is recommended that early warning or incipient-type systems are installed in what areas of the data center?
Where maximum fire protection is required, such as the computer room and entrance room.
Of the chiller room, the electrical distribution room, and the network operations center, which is recommended to have an incipient or early warning system?
Network operations center
True or False: Halon 1301 can be installed in new data centers.
False
True or False: Carbon dioxide should not be used above the access floor in computer rooms.
True
NFPA 72 and ISO 7420 state requirements on what data center design retail?
Smoke detector spacing
