We live in the smart age. You might drive to work in a smart car and text and email throughout the day on your smart phone. But are you working in a smart building? A building controlled by a building automation system (BAS) or building management system is often referred to as an "intelligent" building or "smart" building.
Building controls are the automatic centralized controls of a building's heating, ventilation and air conditioning (HVAC), lighting, motors, and other systems through a BAS or other controls. Energy use can be controlled in order to reduce costs – addition of low-cost sensors and controls have the potential to reduce the energy consumption of buildings by 20%–30%. The objectives of building automation are improved occupant comfort, efficient operation of building systems, reduced energy consumption and realized operating cost savings. Keep in mind that for new building construction, a certain level of controls may be required for lighting, HVAC controls, air ventilation, etc. under local building codes, ANSI/ASHRAE/IESNA standards, as well as the International Energy Conservation Code (IECC). Let's take a quick walk through the different levels of controls, from the most simple to holistic:
Manual Control Systems
Turn equipment off when it is not needed - every piece of equipment has some type of control; an on-off switch. Manual controls are the least expensive, but least robust as they rely on humans. A good example of an energy saving opportunity is exhaust and makeup air fans. Typically located at a high ceiling, these fans can be overlooked and should be turned off when not in use. Another example of manual control is manually turning back a thermostat at night, or manually shutting off a computer at the end of the work day.
Basic Automatic Controls
Basic automatic controls include equipment such as timers and dimmers. Timers can allow a company to start-stop equipment at the correct time so that it is not necessary to wait for staff to turn off equipment or adjust thermostats before a work shift begins. The timers do need to be maintained, and power outages may require timers to be reset. Dimmers can reduce electric consumption by the use of photocell sensors to adjust the lighting based on natural day lighting levels, such as dusk to dawn lighting in a parking lot.
Programmable controllers include some logic capability, but are not computers. Programmable controllers can be used to control outside air for heating, ventilation and air conditioning systems, or may include programmable thermostats which are designed to adjust the temperature according to a series of programmed settings that take effect at different times of the day.
Web-Based Building Automation Systems (BAS)
BAS are not something new, but have advanced and improved rapidly over the last several years with the Internet and with the addition of wireless technology. BAS are a powerful tool for facility managers. Typically, facility managers find that the money a BAS saves them in energy costs will over time offset the installation and implementation costs of the system itself. A BAS is a computer-based control system installed in buildings to control and monitor the building's mechanical and electrical equipment. A BAS works through the use of sensors that measure values such as temperature, humidity, daylight or room occupancy. Controllers are the brains of the systems. Controllers take data from the sensors and decide how the systems will respond. Building automation systems are most commonly implemented in large projects with extensive mechanical, HVAC, and electrical systems (such as a hospital, industry, higher education campus, K-12 school, commercial building, government building). Before starting a BAS project, managers should assemble a team of staff (don't forget your IT staff!) and a consultant, or ESCO (Energy Service Company) to choose a controls company and system that fits your technical requirements as well as your budget restrictions.
Buildings with legacy building controls face a tough decision – is it better to take steps to integrate older controls into a new communications system to keep costs down or spend more now to build in new functionality and retrofit the building controls? ASHRAE's Guideline 13 (2015) offers a chapter on upgrade challenges and what factors can help FMs make the decision. Perhaps it's time to take a look at your controls and modernize them through an upgrade, and make your building smarter?
Learn more by training yourself or your building staff with the Building Operator Certification program or Building Re-Tuning Training.
Learn more about building controls by checking these resources: