Owners of multi-tenant office buildings have a number of fire alarm design options today - thanks to technology advances. Systems can be installed to meet occupancy requirements for common areas, as well as provide the backbone of an expandable system installed as tenant spaces are built-out. After ensuring that all local code concerns are understood and provided for, the system planner and building owner have decisions to make. The local competitive market for space may determine one that deals with cost sharing for the fire alarm system. The sharable costs are derived from the type of system chosen and the portion of the cost allocated to the tenant. In a competitive space market, a systems approach that reduces a prospective tenant's cost without negatively affecting the building owner's budget may be the appropriate action to take.
One approach that fits the goal of providing a tenant-friendly fire alarm system in many small- to medium-sized buildings is to install an intelligent addressable expandable fire alarm control panel. Activate a Signaling Line Circuit (SLC) to monitor devices in common areas and control fans and elevator recall functions. Be sure the panel selected has expansion capability to handle the needs of each tenant area. Fire alarm panels are available that can accommodate 2,000-plus input/output devices. Depending on floor sizes, this can be accomplished by either assigning one SLC per floor or multiple floors. Since each device connected to a SLC is individually addressed, its display and outputs can be tied to the requirements of the tenant's floor, allowing a single SLC to be applied to multiple floors. However, this approach carries the potential limit created by the number of devices input and output each SLC is capable of supporting. The number of devices per SLC varies by manufacturer and may be further limited by the mix of input vs. output devices. This approach works best in new installations and is also successful in retrofit applications if the equipment selected can use existing wiring.
A second approach is installing a network system where each tenant has a dedicated fire alarm control system for its area. This approach can be more expensive and is more suitable for larger buildings and multiple-building applications. With the additional investment, it does provide for maximum expansion capability that is limited only by the size of the individual panels.
Another consideration is the type of local notification devices required as part of the system. The most common are horns with strobes used to alert occupants of a fire emergency. A second means of notification is emergency voice evacuation systems. Both types can be applied to a backbone system approach. The advent of notification appliance circuit expanders with built-in horn/strobe synchronization drivers for maximum design flexibility and distributed audio panels makes this possible. The use of expanders also facilitates the meeting of ADA requirements.
The careful review of the capabilities of prospective fire alarm systems, coupled with an understanding of local codes and requirements, will ensure that both current and potential future needs of a building owner and each tenant can be accommodated in a cost-effective manner. A flexible main fire alarm control panel and system design will make the process of adapting to changes in either tenants or code requirements less challenging.
Ken Beeson is vice president of marketing at The Gamewell Co. (www.gamewell.com), Ashland, MA.