Many building owners and occupants who want to cut operating expenses and improve energy efficiency look to replacing or upgrading systems such as HVAC and lighting. If done with proper planning and the knowledge of how systems interact, this can be an effective step toward reducing expenses and energy usage. However, it is also important to plan for the management and actual usage of the systems once they are in place. This is where Building Automation Control Systems (BACS) or Energy Management Systems (EMS) can take efficiency to the next level.
Also known as Direct Digital Control (DDC) and Building Management System (BMS), control systems range from simple programmable thermostats to complex, sophisticated systems that control multiple facilities. Control systems typically contain three primary components:
- The automated system that provides controls for HVAC, lighting and other systems within the facility
- Energy information systems that work with the controls to provide energy data to operators and energy managers
- The participants in the automated system that result in system efficiency
These systems perform functions of programmed commands for HVAC, ventilation, temperature and lighting commands. They typically record data that includes utility demand and energy use, building conditions, climatic data and status of controlled equipment. The data furnished by the control system is vital to managing energy usage – only when it is measured can it be managed.
New or existing systems need adjustment based on conditions and use, which is difficult for staff to manage. Sequencing multiple processes is best completed by automatic controls designed specifically for that purpose. Leaving the control of energy systems to the occupants can have a major and historically negative impact on energy usage. Even if an old HVAC system is replaced with a new, energy efficient unit, the effect of individuals raising and lowering the temperature at will can be detrimental. Human interaction with manual controls often taxes the system and decreases efficiency and consistency in the equipment that is being controlled. The efficiency of facilities is improved radically when control routines are established and implemented within an automated control system.
Countless configurations and smart technologies can be put to work in building automation systems. Occupancy modes such as unoccupied, warm up and night setback can be used to set schedules for lighting and temperature control. All equipment should be brought to set points before being occupied, through use of the proper automated sequence. The system should also take into consideration outside climate conditions, equipment capabilities and indoor temperatures to ensure the systems start at the appropriate times and are ready for occupancy.
Occupancy sensors, photo sensors and timers can be used to automatically turn off lights and control climate. Building automation can also have sub-systems such as room automation, which is often seen in large rooms that might not be used consistently and have a number of devices that require controls. Presentation rooms, lecture halls or corporate boardrooms can be controlled based on use and occupancy, as well as streamlining controls of lighting, computers and video equipment under one control system.
After making the decision to implement an automated control system, it’s important not to assume the system is providing energy efficiencies. A thorough verification and measurement approach will provide evidence that systems are properly automated and resulting in savings and greater energy efficiency.