Integration examples: Fire alarms and BAS
Examples of integrating building automation and fire alarm systems for special circumstances are shown.
Using a fire/smoke damper that is part of an engineered smoke control system complying with International Building Code Section 909 as an example, at each damper location we have a smoke detector for detection of smoke, an actuator that controls the opening and closing of the damper, and an end switch to provide positive confirmation of the damper open and closed position. Because the fire alarm system already needs to have circuitry to this location for individual smoke or duct smoke detectors, that same pair of wires can be used to monitor the open and closed position of the damper, essentially eliminating two pairs of wires back to the BAS controller. The position status signals of the damper can then be transmitted from the fire alarm system, through the gateway, and into the BAS along with the active alarm point information. This leaves the wiring to the actuator as the only BAS wiring needed at the damper location.
As another example, let’s use a stairway pressurization fan that is being controlled by a variable frequency drive (VFD). Typically, a VFD would be connected to the BAS via a digital signal while the fire alarm system would provide override of the VFD using dry contacts to stop it or put it into a smoke mode condition. Allowing the BAS to perform all of the control functions permits the adjustment of the fan speed through the BAS to regulate for atmospheric conditions by employing other equipment connected to the BAS, such a digital differential pressure sensors. Using the BAS solely for control eliminates any connection to the fire alarm system, with the activation commands being sent through the gateway.
Taking advantage of the aforementioned efficiencies gained by integrating the BAS with the fire alarm system requires planning in the design process. This planning process is the same whether it is a design build or a design assist type of project delivery. The building owner and operator must be involved in the process of establishing the design criteria or at the least have influence over it. In a typical design build or design assist process, the integration of these two systems is an afterthought and often never considered. The end user must be made to understand that the efficiencies gained by integration will pay dividends long into the lifecycle of the building.
Jon Kapis is the operations manager in the Seattle office of The RJA Group, and has more than 32 years of experience in fire alarm and building systems integration. Rick Lewis is a senior consultant in the San Francisco office of The RJA Group, with more than 28 years of experience in the fire and security alarm industry. Craig Studer is vice president in the Chicago office of The RJA Group, with more than 30 years of consulting experience in building commissioning and system integration.