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Herb Knieriem, P.E., LEED^® AP, Sacramento Principal and Lee Fleming, P.E., Sacramento Associate Electrical Engineer

Recent legislation and a higher concern for life safety have created a major increase in fire detection and alarm system modifications. Before undertaking such a task, the design team should consider many items, which may have a significant impact on the design and ultimate construction. Also, several jurisdictions now are requiring the fire detection and alarm system be fully designed prior to issuance of a building permit. As a fully designed system, unknowns in design development can lead to change orders in construction.

The first consideration must be for the applicable code. Many factors are used to determine which code applies to a particular installation. The UBC, the UFC and the NFPA should be reviewed carefully to determine which codes apply to the facility. In addition, local codes and ADA are also to be in force. Typically, the codes would have changed since the original installation and that installation may not meet current codes. To replace the existing fire alarm system exactly as installed would be a huge mistake. Codes for certain facilities have dramatically changed. For example, in California, the Green Oaks Family Academy Elementary School Fire Protection Act (SB 575) now requires an automatic fire detection and alarm system for all facilities serving grades K through 12. The occupancy of the facility may have changed, due to code changes, thus requiring a different type system (speaker vs. horns). There is no shortcut to a thorough investigation of all applicable codes prior to beginning a project.

Often, as with the Green Oaks Act noted above, the full enforcement of the code is dependant on the budget or extent of the project. Usually, fire detection and alarm modifications are undertaken as a byproduct of another driving project. The more significant the project, the more extensive the retrofit of the existing fire detection and alarm system. The modification must also fit within the budget constraints placed on the overall project. Initial budgeting of the fire detection and alarm system should be made to assure the owner and all participants are fully aware of the impact. While the costs of the new systems are not that great, the cost to install can be daunting. Replacing an existing manual system with a new automatic system may require extensive rewiring within difficult to reach spaces. Often the labor to install a new system far outweighs the cost of the equipment.

A thorough review of the existing facility and the existing system should be made. Often as-built fire detection and alarm drawings or calculations do not exist. The location and type of all devices should be noted during this review of the facility. All spaces should be reviewed to determine what devices and what quantity of devices will be required. In addition, many back boxes for existing pull stations and notification appliances may need to be relocated as these devices may not meet the current criteria established in the Americans with Disabilities Act (ADA). Often the existing system is a "line voltage" system, which either only marginally functions or in which parts can no longer be obtained.

The engineer should discuss the fire detection and alarm system with the user or facility maintenance personnel to determine their preferences and proficiencies. The system should be specified to match the expertise of the individuals who will be operating and maintaining the system. There are many choices in selecting the type of system, analog, digital, one loop, Class B, etc. These options should be discussed with the user and the maintenance personnel. In addition, the location of the main panel as well as the location of any annunciation panel should be discussed with users as well as the project architect.

The system will require constant monitoring by a certified off site facility similar to ADT. A phone line with dial tone will be required at the fire alarm panel. Many of the new PBX systems allow for a direct dial tone. The extension of this line should be coordinated with the users information technology or telephone technicians.

Future expansion and flexibility should be considered when sizing the system. To install a system without capacity for future expansion may be a disservice to the owner. Having said this, the system should also be sized to the facility. Expensive, highly responsive, equipment may be of little use to the user.

When laying out the new fire detection and alarm system, many additional factors must be considered. The location of devices is well defined within the NFPA, however, existing conditions may make these placements impractical. The use of multi candela strobes can be very useful in retrofitting an existing facility.

Whenever new devices are to be placed in an existing facility, wall or ceiling openings will need to be created. Location of access panels, as well as location of devices should be carefully coordinated with the Architect. We recommend the Architect place each of the new devices on their elevation drawings. The access to many of the spaces requiring new devices may be limited. In addition, once the access has been obtained, surprises, like large beams may be found. This would define many more spaces above the ceiling requiring heat detection.

Lastly, the new fire detection and alarm system may need to interface with other existing devices or other alarm panels. As much information as practical should be obtained relative to these devices before the system is designed. Voltage compatibility, addresses, and contact compatibility are only a few of the items that should be considered. Often additional interface modules are required to activate, de-activate or otherwise monitor existing devices. Some typical devices include, elevator recall, door hold open, duct smoke detectors, fire smoke dampers, fire curtains, and smoke removal systems.

The more the designer knows about an existing system and the existing facility, the more informed decisions he or she can make. The better decisions will mean a better system installation will follow.