Building controls are one of the most overlooked and underrated systems in commercial buildings. Most experts believe it is because controls are one of the last systems installed and subjected to budget constraints. Inadequate controls can lead to 50% higher energy costs and add 25% more to the operations and maintenance budget. There are four specific areas related to controls: HVAC, Lighting, Plug Loads and Metering & Feedback.
As one of the “big three” energy uses in buildings, the HVAC system is a natural target for improvement. Interestingly, HVAC equipment has increased in efficiency over the years to the point that there are no large savings to be gained from simple equipment “swaps.” The real savings will need to come from the use of new system configurations, recovery and reuse of energy, and most importantly, from more reliable and sophisticated control. Innovative designs for buildings that are approaching and achieving Net Zero provide a glimpse of what a super-efficient HVAC package might look like.
Lighting in commercial buildings is responsible for 20% of the total energy and 38% of electricity consumption in commercial buildings. Thus any attempt to reduce energy use in buildings must address lighting efficiency as a primary issue. There are three elements that need to be considered from an energy standpoint: fixture selection, lighting control and daylight harvesting.
While the equipment and lighting used in commercial buildings becomes increasingly more energy efficient due to more stringent codes and regulations, unregulated plug-load energy use in commercial buildings continues to rise at an alarming rate. According to the Annual Energy Outlook Report (EIA 2006), energy consumption for office equipment is estimated to grow 4.1 % annually while the energy used by PC’s alone is anticipated to grow by 3 percent annually. This growth highlights the need to address the energy reducing opportunities associated with these office plug loads.
Metering & Feedback
Advanced metering and active feedback is not widespread in commercial buildings of any size. In small to medium commercial buildings (those approximately 50,000 ft2 and smaller) there is an even more difficult cost/benefit problem to justify metering and feedback. Recent trends towards “app”-based integrated controls for smaller spaces, performance-based policy and regulation, designing for meterability, and growing familiarity with equipment and options indicate that these technologies will eventually provide the foundation for widespread metering and feedback.