Sustainable Building Technical Manual - Etn-presco.net

❑ Optimize system efficiency.HVAC systems consists of several different types of equipment including fans, pumps,chillers/compressors, and heat-transfer equipment. The performance of the overall HVACsystem should be optimized over that of any individual component. For example, the coolingsystem components should be optimized as a system, including the chiller, pumps,cooling tower, cooling coil, and distribution piping.❑ Design for flexibility.The HVAC design should provide flexibility to address future changes in the building and itsfunctions and use over time. Planning for change includes factoring in potential new users.Control Systems❑ Design a building-management control system.The continued development of microprocessor-based building controls and sensors has ledto a revolution in control-system applications. Individual equipment components oftencontain electronic intelligence and the ability to coordinate their operations with those ofother system components.– Consider the use of direct digital control (DDC) electronic systems for all functions,including central equipment control and zone-level management. This provides greaterenergy-efficiency capabilities, accuracy, and flexibility. Zone-level control features areimportant because sensors in each zone directly measure factors such as temperature, airflow,lighting, and whether the area is occupied or unoccupied. These control features arelinked to the central systems and can be used to optimize system functions.❑ Train building engineers to use the control system for greater comfort and efficiency.Proper use of the control system’s remote reporting, diagnostic, and troubleshooting capabilitiesallows the building engineer to monitor and modify system operations for optimalenergy efficiency, lighting use and HVAC performance.❑ Integrate the operation of all components and install a centralized computer interfacethroughout the project.Coordinate various building management functions (energy, lighting, life safety, security,elevators, etc.) by integrating occupancy sensors, daylighting control, temperature control,and ventilation levels.❑ Ensure that HVAC control systems include the following functions:– Basic featuresa. Comfort control (temperature, humidity)b. Scheduled operation (time-of-day, holiday and seasonal variations);c. Sequenced modes of operation;d. Alarms and system reporting; ande. Lighting and daylighting integration.– Additional capabilitiesa. Maintenance management;b. Indoor-air-quality reporting;c. Remote monitoring and adjustment; andd. Commissioning flexibility.Air-Delivery Systems❑ Use variable-air-volume systems.This approach reduces energy use during part-load conditions and takes advantage of eachzone’s operational characteristics.❑ Avoid reheating for zone temperature control.Consider a dedicated-perimeter heating system and the use of room return air for heatingto minimize outdoor-air reheat penalty.