by Kevin Callahan
In the same way today’s mobile phones have capabilities far beyond traditional telephones, modern building automation systems (BAS) have added many benefits transcending their original roots in heating and cooling control.
Today’s BAS help facility professionals obtain greater efficiencies from numerous building systems, including:
- security/access control;
- fire and life safety;
- elevators and escalators;
- irrigation; and
An appropriately equipped BAS can also meet specialized needs such as emergency and critical systems monitoring in hospitals, and tenant billing for leased spaces in office buildings.
With rising energy costs, an increasing number of building owners and operators are including BAS in new buildings, as well as in retrofits. More than half of U.S. buildings larger than 9290 m2 (100,000 sf) have a BAS installed.1 The market is forecast to grow between seven and nine percent from 2014 through 2017, for a net growth of more than 40 percent above the 2012 level, according to researchers at IHS Technology. A key driver of this “/>growth is a projected eight percent annual increase in retail electricity prices through 2020.2
Automation can reduce a building’s total energy consumption between five and 15 percent annually because of more efficient control of various building systems. Savings can surpass 30 percent annually in older or poorly maintained buildings. Additionally, a BAS can help reduce building maintenance costs by alerting facility managers when equipment is operating outside of specifications and therefore might be at risk of failure.3
- control and diagnose what is going on in buildings;
- create a graphic representation of building settings;
- see and fix programmatic problems quickly;
- generate reports usable by management for tracking energy consumption and the operational status;
- schedule and control temperature settings for increased energy savings; and
- collect and store data on energy consumption over long periods.4
From commercial offices and government buildings, to schools and hospitals, energy saving benefits can be achieved in virtually every type of project.
Seattle’s Columbia Center is the tallest building in the Pacific Northwest, with 76 stories and 142,900 m2 (1,538,000 sf) of total floor area. A BAS integrates all the building’s HVAC systems—including 2200 heat pumps, ventilation and exhaust fans, boilers, heat exchangers, cooling towers, and circulation pumps.
The building is one of the city’s largest electricity-consumers, using approximately 111,600,000 megajoules (31,000 megawatt hours) annually. However, with an energy-efficient BAS, it consumes only about 13 percent more electricity than the next highest building electricity consumer in the city, despite having 50 percent more floor area.
In 2009, the state of California opened a new central utility plant in Sacramento to heat and cool many office buildings throughout the city. The 7246-m2 (78,000-sf) facility supplies chilled water and steam to 23 buildings that total 510,967 m2 (5,500,000 sf) of space. One BAS monitors and controls the central utility plant, while another BAS serves the 23 buildings. The BAS for the chiller plant enables it to operate at about half the energy use of a traditional chiller plant.
At Irvington High School in Fremont, California, the local school district installed a BAS as part of a set of energy-saving actions that reduced the school’s energy consumption by approximately one-third, which equates to annual savings of about $10,000. Much of the savings result from data provided by the BAS, which allows the district to shed energy loads under a peak pricing program offered by Pacific Gas and Electric (PG&E).
Eastern Connecticut State University in Willimantic installed a BAS in the Windham Street Apartments—a 30-year old, nine-story residence hall housing 224 students. The BAS reduced the building’s annual electricity consumption by 234,000 megajoules (65 megawatt hours), for a 12 percent energy cost savings. The university achieved these savings despite also adding cooling to the building, when previously it only had heating.
As part of a facility expansion and upgrade project, New York University Medical Center in Manhattan retrofitted outdated building controls in 13 buildings totaling 278,710 m2 (3,000,000 sf). The new BAS enables staff to manage the campus and outlying facilities through a single system, for better energy efficiency. Additionally, trend logs generated by the system illustrate how closely actual room temperatures match the set point, which allow staff to closely control the environment for patient comfort, health, and safety.
Maximizing BAS benefits
To receive the most benefits from implementing a BAS, it is important to focus on analytics and building commissioning.
Analytics for high-performance building operations
A BAS is a powerful tool for gathering data needed to make informed decisions on energy management. To maximize its cost-saving potential, one must pay attention to the data the system is generating and to use it to make strategic energy usage choices—this is the concept of building analytics. In short, a BAS is not a tool to install then simply turn the heating, cooling, and lights on and off according to a set schedule.
Analytics is about ensuring a building’s managers have enough of the right data being collected for analysis. It is important to use analytics to ensure any BAS programs created to reduce energy—or any other objective—are actually accomplishing what was intended. An appropriately equipped BAS allows the facility staff to collect and store data so there is history to compare it to.
For example, analytics can help the facility managers ensure they are not heating and cooling the same spaces at the same time, as well as confirm lights are on for a purpose, rather than solely for convenience. Analytics provide a way to determine whether energy is being wasted, and where.
A BAS delivery agent (i.e. manufacturer, dealer, or consultant) can be a valuable resource for determining what analytics are needed to meet the building owner or operator’s specific goals.
A sometimes overlooked benefit of BAS is the system can be used to simplify the commissioning process, for both new construction and building retrofits. Some BAS include programs to verify HVAC and other building systems are performing according to the design intent. The wall sensors of an advanced BAS enable technicians to access the system throughout the building to conduct tests and verify environmental conditions, without carrying separate diagnostic tools—the result is faster and more accurate performance verification. Proper building commissioning is crucial to achieve efficient building operations.
“The operating costs of a commissioned building range from eight to 20 percent below that of a non-commissioned building,” reports the U.S. Environmental Protection Agency’s (EPA’s) Building Commissioning Guidelines. Additionally, it is noted commissioning costs typically range from only 0.5 to 1.5 percent of construction costs, and reduce operating costs throughout the building’s life.5
For initial commissioning, the building systems as a whole need to be commissioned at the time of construction to ensure they are operating as designed and their integration with the BAS is correct. This helps ensure the building is operated appropriately to satisfy its occupants’ needs. As a basic example, in an office building the HVAC and lighting would need to be commissioned for controlling the indoor environment while the building is in use during standard working hours, whereas in a warehouse the utility needs would be different because the building likely is not in use at all times.
An even more critical action than initial commissioning is the periodic re-commissioning of a building to ensure the systems are still serving the occupants’ requirements. Additionally, because systems can degrade over time, it is important to tune them up for optimal performance.
Specifying a BAS
Design professionals can select from numerous BAS. Several important features to consider when choosing the system include:
- degree of interoperability of the control module;
- software’s ease of use;
- security measures; and
- usability and design style of the wall sensors.
The control module is the central processing unit of a BAS. Until the mid-1990s, the communication protocols these units used to interface with building equipment were proprietary to each manufacturer. As a result, various components would not work together unless using a single manufacturer’s equipment.
In 1987, the American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) began to actively develop a standard protocol to enable a wide range of controls and equipment to work together (i.e. interoperable). In 1995, it published that standard—known as BACnet (data communication protocol for building automation and control networks), which has since been widely adopted by BAS and building equipment manufacturers.6
“Capabilities vital to BA [building automation] applications were built into BACnet from the beginning in order to ensure the highest possible level of interoperability in an environment possibly involving multiple vendors and multiple types of building systems,” according to a report from the Institute of Electrical and Electronics Engineers (IEEE).7
Such interoperability helps ensure a BAS can adapt to emerging technologies and evolving building occupancy needs, without having to start over.
BACnet is unparalleled in providing integration of the disparate systems within a building, including HVAC, lighting, access, irrigation, utility monitoring, and metering. For example, instead of having separate systems and building occupancy schedules for a building’s lighting and HVAC systems, BACnet allows for clean integration of both systems so the scheduling is from one source.
By analogy, a BAS using BACnet is like a symphony orchestra, wherein the control module is the conductor providing direction to the numerous different building systems (i.e. individual musicians) using a common protocol (i.e. BACnet) they all understand (i.e. movements of the baton, hand gestures, and facial expressions). Although a violin is different from a trumpet, the conductor’s common direction enables them to work together to produce beautiful music.
Some BAS control modules incorporate multiple protocols (BACnet and Tridium’s Niagara Framework) for even greater interoperability than relying on a single protocol. Other protocols, like LonTalk, are also available.
Software—ease of use
Learning a new software program often involves hours of training, and/or trial and error, both of which can mean thousands of dollars in staff time. This is especially true for specialized programs such as those included with a BAS.
However, a key differentiator among BAS software is how intuitive and simple it is to learn. Although many programs now employ a graphical interface, rather than text entry alone, ease of use varies. The most sophisticated BAS software includes simple schematics clearly identifying the equipment throughout a building, and its operating status (e.g. heating, cooling). Such programs enable even novice users to readily interpret the environmental or other monitored conditions anywhere in the building, and to adjust the appropriate building system, as needed.
Another simplifying feature introduced with BAS software this year is use of HTML5. With the latest HTML format, facility professionals can access the BAS remotely from any Internet-connected device, without the time and compatibility hassles of downloading a third-party’s software plug-in. As a result of this wide system accessibility, a technician could troubleshoot a piece of equipment from the field, or a facility manager could make necessary system adjustments when traveling away from the office.
As large online security breaches have come to light in recent years, building professionals are increasingly asking about how to secure their Internet-facing building BAS. For the building design team, three cyber security best practices will improve the security of a building automation system against unauthorized access:
- ensure network isolation by deploying behind a firewall or on a virtual private network (VPN);
- use the security features built into the BAS; and
- configure the system securely by disabling guest user accounts and using strong password protection protocols.
Since BAS are networked throughout buildings (and often to the Internet) to enable remote access by facility managers, it is crucial to isolate the automation system from other internal networks, such as financial management or credit card processing. To accomplish this, the building design team should involve the client’s information technology (IT) experts early in the BAS selection process, as this is a specialized aspect of specification writing and usually requires acquisition and installation of additional hardware dedicated to protecting the building networks from both external and internal attacks. This hardware (e.g. firewalls, VPN routers) is extremely important and needs to be state-of-the art to combat the evolving means of attacking networks.
For the BAS itself, a control module with multiple Ethernet ports is an important security feature that helps to isolate the network. Such control modules physically separate the building systems from connections to outside networks. It is also important to specify a BAS that can be configured to use signed certificates for web connections to prevent ‘man-in-the-middle’ attacks when users log into the server. Beyond network connections, another security feature built into some BAS is a system that does not automatically execute code from USB thumb drives. This helps prevent a BAS user from inadvertently introducing a virus or other malware into the BAS.
Securely configuring the system once it is installed is important, so it is critical to ensure the BAS has a security manual that provides information on how to best accomplish this task, and then make sure the contractor follows those guidelines. Additionally, the BAS integrator should have documented the processes and procedures they followed for designing and implementing the system, which will be a crucial reference for the building owner.
Cyber-security threats change frequently, and need constant vigilance. Anyone who touches the system should be trained at a minimum in cyber-security awareness, and ideally should be certified to securely deploy vendor systems. It is also important they are aware of the building owner’s cyber security standards and practices. Building owners should also keep in mind the BAS will require maintenance, which might include patches to the operating system, and anti-virus software updates and management.
Strong cyber-security is a three-legged stool comprising:
- manufacturers and software vendors, who continually evaluate and improve the security of products;
- contractors and installers, who ensure their customers’ systems are properly and securely installed; and
- end-users, who build and maintain a culture of security within their organizations through the use of cyber security best practices.
As with BAS software, a key differentiator among wall sensors is how easy they are to use—important for both facility staff and building occupants. Vendors have become increasingly sophisticated with designing wall sensors. One unit introduced in 2014 was designed according to what users are accustomed to seeing with their smartphones. For example, the unit includes easy-to-interpret icons for temperature control, and clear navigation tools to see interior and exterior temperatures, relative humidity (RH), and carbon dioxide (CO2) levels. To enable building occupants to see the HVAC operating condition from across the room, the unit has color light-emitting diode (LED) lights along its bottom to indicate either heating (red) or cooling (blue).
In terms of design styling, in commercial buildings, thermostats have often been visually ‘boxy.’ Now, manufacturers are focusing on aesthetics of these units in addition to performance. Some units are designed to be sharp and crisp with a low profile to complement modern architectural styling. Building owners and occupants have even gone so far as to say such units are ‘sexy.’ At any rate, a thermostat does not necessarily need to be a clunky box hidden around a corner, but can be a sleek addition to a room or hallway.
A properly equipped and configured automation system can save building owners tens of thousands of dollars or more on annual energy costs. Additionally, some facility professionals use the systems to save costs in other ways. For example, in Russellville, Arkansas, the school district officials use their BAS to monitor food and beverage freezers and coolers in schools throughout the area. The system sets off an alarm if temperatures begin to go out of range, which enables the facility staff to take prompt action and thereby avoid costly and wasteful spoilage.
To maximize the cost savings, when specifying an automation system it is important to think about each component—control module, software, and wall sensors—and consider how easy they are to use, and how flexible they are to changing technologies and building user needs.
1 For more, see “Building Automation Systems” at fpl.bizenergyadvisor.com. (back to top)
2 Visit “U.S. Building Automation Market Primed for Growth,” at technology.ihs.com. (back to top)
3 See note 1. (back to top)
4 See www.bu.edu/facilities/what-we-do/buildings/building-automation/ for more. (back to top)
5 Visit “EPA Building Commissioning Guidelines” at www.epa.gov. (back to top)
6 See “BACnet overview” at www.bacnet.org. (back to top)
7 See “Communication Systems for Building Automation and Control,” by Kastner, Neugschwandtner, Soucek, and Newman, Institute of Electrical and Electronics Engineers (IEEE), at www.researchgate.net. (back to top)
Kevin Callahan is a product marketing manager for Alerton, a Honeywell business. He has 38 years of experience in the building control technologies field, including control systems design and commissioning, facilities management, and user training. Callahan can be reached at firstname.lastname@example.org.