Energy efficiency in highrise multi-residential buildings can be achieved through a variety of retrofits including lighting, variable frequency drives, carbon monoxide monitoring systems and occupancy sensors. However, one method that is often overlooked is the use of a building automation system (BAS). These systems can improve energy efficiency within the building’s mechanical plant.
A mechanical plant is a complex system of boilers, chillers, pumps, valves and fans that provide heating, cooling, ventilation and water throughout the building. When the building systems are functioning properly, residents don’t notice them. But when they’re not, they can cause a lot of complaints.
The mechanical systems are generally set to meet the highest demand expected for a given season and not necessarily the actual demand at a given time. Essentially, the different elements of mechanical equipment are designed to run at full speed and power at all times, which can result in wasted energy consumption.
A building automation system allows for control and integration of the building plant. By scheduling, adjusting and monitoring the major mechanical plant equipment, the system becomes more efficient, reduces energy consumption and operating costs, all without sacrificing resident comfort.
Although most building automation systems are designed primarily for HVAC control, many systems can also incorporate additional functions such as lighting control, computerized maintenance scheduling, life safety functions and security access control.
The biggest benefit of a building automation system is energy savings. Most engineering sources estimate that the total energy savings are between five and 15 per cent of a building’s annual energy consumption. This means thousands of dollars in annual savings.
In addition to saving energy, a building automation system can reduce overall building maintenance costs by identifying operational problems.
There is a wide selection of energy services companies that supply and install building automation systems.
The cost will vary depending on the complexity of the building. The more complex the building, the more “points” required to control the building’s mechanical system. In addition to the physical side (labour and hardware), the building automation system must then be programmed with the various schedules and commands to maximize energy efficiency.
After the building automation system has been installed, certain companies will continue to monitor the building systems. Technicians will regularly check the various points and, if necessary, take whatever steps are required to bring critical systems back online as quickly as possible. The monitoring service will generally include annual reports, preventative maintenance, trend and alarm reports, and scheduling changes. Schedule changes are important as it will involve the continual optimization of equipment operating parameters. Without a monitoring service, it is up to site staff to maintain and control the complex system.
A building automation system can be installed during the construction period or as a retrofit for existing buildings.
The capital cost to install a building automation system can be steep. But the energy savings can be impressive. It is estimated that a typical building automation system retrofit can have a payback period of less than three years.
Building automation systems are also eligible for incentive rebates. The incentives will further shorten the payback periods.
Jennifer Young is the sales and marketing coordinator at Provident Energy Management Inc., an energy services company that provides energy efficiency solutions for multi-residential facilities. She can be reached at jyoung@pemi.com.
