Building Automation Functionality in Emergency Situations

You probably know that a good building automation system can help reduce your operating costs. But in addition to energy management, a BAS adds automated control and management to other building operations, such as fire and safety, security, and elevators.

The East Coast has been rocked (with an earthquake) and roiled (one hurricane behind us and another on the way). It seems like a good opportunity to talk about making emergency situations easier to contend with.

General features applicable to the BAS as a whole include:

  • Trend monitoring
  • Maintenance reminders
  • Security access
  • Protection during and after power failures
  • Lighting control systems
  • Automated fire and life safety security systems
  • Security systems
  • Elevator control systems

Let’s focus on two of these: power failures and fire/life safety.

Protection During and After a Power Failure

If power is temporarily interrupted, a good building automation system can review and restore the operation of fans, motors, pumps, chillers, and other points in sequence in order to prevent power surges. The system restores critical items first, in case power is limited. During a power failure, most intelligent units rely on battery backup to retain program memory and time-clock information. Older systems may not have this feature and may require reprogramming once power is restored.

It is essential that the BAS and critical field panels are powered from both a UPS (uninterruptible power supply) and the emergency generator, so that power is never lost to the system. It is important to note that most power failures are internal and not a result of a power company failure. If one area of a facility loses power while the rest of the facility operates normally, it is possible that critical equipment could be down without an alarm being initiated.

Automated Fire and Life Safety Systems

These systems protect people, equipment, and building assets by detecting fire, smoke, and heat and activating equipment in response. The key features of these systems are:

  • Alarms and voice commands. Systems will activate audible alarms or signals, or they will broadcast prerecorded messages that direct occupants to smoke-free areas or escape routes. Highly sophisticated systems have the capability to control individual or select groups of audible devices. Most systems are equipped with microphones for live announcements as well. A good system will also inform the operator, from the console, of the exact location of the alarm. The screen should display alarms in order of priority.
  • Smoke control. In each fire zone, the fire management system can be programmed to open exhaust dampers and close supply and return-air dampers. Simultaneously, in adjacent areas, it can open fresh-air dampers. The program should be flexible enough to accommodate specific procedures dictated by local building codes. When a fire alarm is activated, the system should positively pressurize stairwells, elevator shafts, and areas around the fire to keep smoke from entering these spaces. The program can also introduce fresh air to occupant refuge areas.
  • Elevator control. The building automation system should be interconnected with elevator controls so that it can close elevator doors and return cars to the lobby for use by firefighters. Smoke detectors activated in upper-floor elevator lobbies can signal elevators not to stop there. The system should automatically close fire doors to contain smoke and flame, and unlock building exits for occupants and firefighters.
  • Firefighter control and communication. Most often located in the front lobby, annunciator panels provide start/stop control over a combination of fire, security, and HVAC points. During a fire, the main console should allow building personnel and firefighters to easily interpret alarm data and offer sufficient control over critical building systems. It should provide information about the source and spread of the fire, both on the terminal screen and in hard copy. A hard copy provides a permanent record of the time, date, and description of each alarm sensed by the system for use by firefighters, building officials, and insurance carriers.

    In large buildings, communication between floors or remote building areas may be necessary for efficient firefighting. Comprehensive fire management systems offer two-way communication between stations on each floor, mechanical equipment rooms, elevator machine rooms, and air-handling rooms.

    Some systems have intelligent field units that allow local operation of critical fire management functions. This capability provides the facility with reliable, uninterrupted fire protection even when major systems are disabled.

Fire management systems can be separate from the energy and climate control systems, or they can interface through a shared CPU. The latter configuration is preferable, since the interconnection between fire and HVAC systems makes it possible to pre-establish interactions between smoke detection and HVAC components in each building zone.

A note of caution is in order. Some facility managers have found that local fire departments may prefer traditional annunciator panels to computer screens because their personnel are not always computer literate. In addition, early systems crashed when all fire detection equipment was wired to a head-end unit. Newer systems have taken advantage of LANs (local area networks) to permit intelligent field panels to communicate with the head-end unit without depending on it. This configuration provides some system redundancy and reduces the likelihood of crashes.

NFPA (National Fire Protection Association) standards require that, when a fire alarm system is connected to anything else, the combination must not adversely affect the fire alarm system. This issue becomes real when systems are integrated and open protocols are used.

In all cases, it is the local authority having jurisdiction who ultimately decides what can be integrated into the building automation system. By including the fire marshal, fire chief, or fire inspector in the planning of this part of the system, you will ensure acceptance of the system in the form of an occupancy certificate.

This article is adapted from the BOMI International course Technologies for Facilities Management. More information regarding this course is available by calling 1-800-235-2664. Visit BOMI International’s Web site.