The U.S. Department of Energy and its National Renewable Energy Laboratory (NREL) have released two technical reports that provide recommendations on how to achieve 50% energy savings in large office buildings and large hospitals.
Technical Support Document: Strategies for 50% Energy Savings in Large Office Buildings evaluates the potential for new large office buildings to achieve a 50% net onsite energy savings compared to a baseline standard (as defined by ANSI/ASHRAE/IESNA Standard 90.1-2004). The report found 50% energy savings can be achieved in both low-rise and high-rise office buildings in a broad range of U.S. climates. The analysis was conducted in 16 cities that represented different climate zones, such as hot and humid, hot and dry, marine, cold and humid, and cold and dry. The following energy-efficiency measures helped researchers reach the 50% energy-savings target:
•Lighting power density was reduced in office spaces and occupancy sensors were used in infrequently occupied spaces.
•High-efficiency boilers, chillers, air distribution units, and service water heating equipment were installed.
•Plug loads were reduced by purchasing high-efficiency electronic equipment and using special controls that shut off equipment when not in use.
Large Hospital 50% Energy Savings: Technical Support Document details the technical analysis performed and the resulting design guidance that will enable large hospitals to achieve whole-building energy savings of at least 50% over the above standard. The large hospitals report also documents the modeling methods used to demonstrate how the design recommendations will help institutions meet or exceed the 50% energy-savings goal. This report found 50% energy savings can be achieved in large hospitals across all eight U.S. climate zones. Energy savings range from 50.6% to 61.3%, with the smallest savings in humid climates and extremely cold climates. The highest energy savings were achieved in marine climates, with relatively high energy savings achieved in dry climates. In general, for each climate type (humid, marine, and arid), savings were seen to decrease as the climate became progressively colder.