Assessing the goals
Technology advancements are driving the expectations of building owners and occupants. One shoud start by determining what the building owner or manager wants to achieve. Do they want a greater understanding of building performance? The ability to track utility trends? An easier way to remotely control building setpoints to improve occupant comfort?
A connected building is the answer to all of those goals.
Decisions with data
A connected building starts with a building automation system (BAS), which aggregates data from equipment with the ability to connect to the cloud or the Internet. As more connected devices are integrated into networks, more value can be delivered.
The real business value is in the data that informs building owners and facility managers how systems are operating and performing. The BAS can collect trends about average setpoints over a certain period, how often equipment is running, and hours of building usage. This information can be delivered in easy-to-read dashboards.
Equipment metering can also be integrated into a BAS, providing detailed utility data such as average kilowatt hour usage for specific pieces of HVAC equipment.
This information helps building owners and facility managers make informed decisions about how to operate the equipment to achieve better energy efficiency, track maintenance requirements, and dispatch service/maintenance personnel automatically upon request.
Once one has a clearly defined strategy identifying the goal of using data, including why it is needed and the benefits it will generate, the tactics—including what data is necessary, how to get it, and what databases should be mined—become clear. For example, interval data can be very useful in determining where inefficiencies exist in a facility, and there are tools available to help find where these inefficiencies occur.
The interval data in Figure 1 indicates poor start and stop performance of the facility with electrical load showing up during unoccupied periods. Figure 2 shows in 3D inconsistent peaks and valleys in operation along with the use during unoccupied periods.
Integrating building systems
A connected building can go beyond HVAC equipment by integrating other systems such as lighting, security, water, window shades, and elevators. BAS can dim lights, raise building setpoints, or slightly slow down elevators and escalators. Typically, these actions are not noticeable to occupants, but there are potential financial benefits.
This level of integration enables designers and managers to look at the building as an integral whole and assess the performance as a group of integrated/interdependent systems rather than
as independent pieces.
American Society of Heating, Refrigerating and Air-conditioning Engineers (ASHRAE) Guideline 13-2015, Specifying Building Automation Systems, provides designers with recommendations for good practice, project considerations, and detailed design options.
Varying types of systems, and even equipment from different manufacturers, can be integrated if they speak the same language. Or in other cases, a communication bridge can be used to connect equipment that does not speak the same language.
Designers and specifiers should look for equipment and systems using open and standard protocols, such as BACnet, LonWorks or ZigBee. The use of standard protocols helps ensure integration of different types of systems and equipment.
BACnet is a communications protocol for building automation and control networks developed under the auspices of ASHRAE. The protocol is supported and maintained by ASHRAE Standing Standard Project Committee 135. In this author’s experience, BACnet is the most prevalent protocol within the North American HVAC industry.
The LonWorks networking platform is integrated with the International Organization for Standardization/International Electrotechnical Commission (ISO/IEC) 14908-1:2012, Information technology—Control network protocol—Part 1: Protocol stack, for commercial building automation, controls and building management.
The Zigbee standard is a wireless communication protocol applicable to communication among devices in applications such as home entertainment, industrial control, and building automation.
