Building automation affects the building occupants’ safety, automates various subsystems’ functionality within the building and can lead to reduced costs. The approach used to reach these goals, however, is varied, and it depends to a great extent on the makeup of a building’s occupants. HVAC systems, security alarms, access control, CCTV, elevator control, intercom systems, parking lot controls and fire systems can all be subsystems that are integrated to develop a totally automated building. The exact automation solution for a given building will be based on the building owners. Automation is in the eyes of the beholder.
Total building automation brings to mind a “smart” building that operates efficiently from an energy management and a people flow standpoint. A “green” building that has reduced power consumption and uses the latest in building materials, technology and automation, also comes to mind. Automated buildings have existed for some time in both Europe and the United States, but recent interest in conservation and increasing energy costs, etc., has renewed a desire to build and operate smart buildings.
This article will describe some of the typical subsystems that compose an automated building. We will assume our subject building has incorporated “green” technologies to reduce power requirements. As you will see, automating a building is a creative endeavor with many possible solutions.
Energy Savings Strategies
Energy can be saved by lowering consumption or turning off equipment and lighting entirely; or, by shifting heavy energy use from the peak demand periods during the day to non-peak demand periods. This can be accomplished with an energy management system that sheds unnecessary loads during periods of peak demand.
To lower energy consumption, lights and heating/cooling (HVAC) can be turned off or significantly reduced when no one is in the area. This can be accomplished with a device that has digital or analog outputs to control fans, chillers, lighting controls, etc. A digital output (D0) is normally a low-current, solid-state switch closure that drives a relay contact, which, in turn, can be used to carry more current when the D0 requires an interconnection directly to an electrical device. For example, the current used to activate an electrical contactor that controls a fan or lighting device would require less current than a switch closure that handles the current that operates the lights. The analog output (A0) is a variable current that can be used to activate a modulating damper or waterline valve for heating or cooling. Energy management systems use D0, Digital Input (DI), A0 and Analog Input (AI) function to control HVAC, lighting and other functions in the building. D0 also exists in a security alarm and/or access control system; therefore, those systems could be used to turn lights or HVAC systems on and off.
Electronic Access Control
The access control function is a vital part of a total building automation concept, by enabling authorized people flow and restricting access to various areas in the building. The way it is used will depend on the owner and the building’s use.
For example, if a single company owns and occupies the building, the company’s culture will dictate the philosophy of access control. In this situation, badge readers on the elevator might be used to gain access to certain floors, or a vestibule area on the executive floor itself might use badge reader control to enable access to the executive floor. In the case where the building has multiple tenants, each different tenant floor or area might incorporate a vestibule area with a receptionist and “after-hour” badge readers. Elevator control (via badge readers) might still be used on certain floors.
A building lobby could use optical turnstiles for faster access of many people, regardless of how many different tenants occupy the building. If the tenant space is designed for other uses than typical office environments, the access control will be much different. The access control philosophy for a retail tenant building, for example, would differ greatly from the office building environment.
The CCTV coverage of important areas is critical. These areas vary depending on the building’s use, but there are several areas where CCTV is important no matter the application — including dock areas, high-value goods areas, the lobby and receptionist, the perimeter of the building and the parking garage or parking lot.
Other sensitive areas within the building that might be covered by CCTV include elevator landings or executive office areas, if the building has a single-company occupant. Connecting the CCTV, security and access control systems allows automated camera coverage for people movement into areas of concern. It could be a door alarm sensor or badge reader activation where the video would provide additional security for someone entering or leaving the parking garage, for example.
CPTED for Automation
Although it requires no electronics, Crime Prevention Through Environmental Design (CPTED) is another functional area that should be part of a totally automated building. CPTED automates the building by facilitating authorized people flow and restricting non-authorized access via physical layout and barriers.
Lobbies, for example, provide an excellent application to incorporate CPTED, as it can be designed to focus everyone to the receptionist desk. This can be accomplished by situating the elevators beyond or behind a receptionist’s desk, therefore ensuring that a person must pass the receptionist’s desk to gain access to the elevators.
Additionally, placement of walls, plants, and the shape of the reception area can help accomplish this in a very subtle way. The receptionist or control center operator can also use electronic hardware such as an elevator recall, panic button, intercom, CCTV monitor, etc., at their desk to aid them in controlling access.
Fire alarm systems are normally considered as life safety systems and not part of a building automation system; however, the fire alarm system can provide automation from a safety standpoint. For example, when a fire alarm system activates, access is allowed and restricted depending on the desired flow of people out of the building. Elevators are immediately sent to a “home” location and will not function again until the fire alarm condition is over.
Automated revolving doors often require breakaway leaves that the fire system activates, which release the doors. If electronic “hold open” fire doors are incorporated, then they are released by the fire alarm system activation, which allows them to close to control people flow. During the fire alarm activation, access into stairwells must be “free” to comply with regulations. Areas of high population density (500-plus people), such as a movie theater requires an override of the building music systems or the theater audio system by the fire system.
Mastering Building Automation
Building automation is more of an art form than a science. It requires flexibility, learning the capabilities of each system, understanding the various system architectures and knowing how to make them operate to accomplish your total building automation philosophy. The number of possible subsystems is not limited to the ones discussed in this article — there might be public address systems, pager systems, car park management systems, intercom systems, and more.
The level of automation and integration of each subsystem depends only on cost constraints and your imagination.
Robert Pearson is a registered professional engineer and a member of the National Standing Committee for ASIS International. He teaches on integrated security systems and corporate security management at the The George Washington University in Washington, DC. He is also a consultant for the Strategic Oil Reserve and manager of electronic security systems for Raytheon Company.