Constructing a building to the requirements in the 2013 version of ANSI/ASHRAE/IES Standard 90.1, Energy Standard for Buildings Except Low-Rise Residential Buildings, can result in 6- to 8-percent greater efficiency than constructing the same building to the requirements in the 2010 version, an energy-savings analysis performed by Pacific Northwest National Laboratory reveals.
On a nationally aggregated level, building-type energy savings range from 19.3 percent to 51.9 percent, while energy-cost savings range from 18.6 percent to 50.6 percent. These figures include energy use and cost from whole-building energy consumption, including plug and process loads.
Sixteen building prototypes were modeled in 17 climate locations for a total of 272 combinations of building type and climate zone.
The energy reduction was achieved through 33 addenda, the most significant concerning:
• Building envelope—opaque elements and fenestration requirements were revised to increase stringency while maintaining a reasonable level of cost-effectiveness.
• Lighting—daylighting and daylighting-control requirements, space-by-space lighting-power density limits, and thresholds for toplighting were modified.
• Mechanical—efficiencies for heat pumps, packaged terminal air conditioners, single packaged vertical heat pumps, air conditioners, and evaporative condensers were increased. Also, fan-efficiency requirements were introduced. Additional provisions address commercial refrigeration equipment, controls on heat-rejection and boiler equipment, requirements for expanded use of energy recovery, small-motor efficiencies, and fan-power control and credits. Revision-control requirements were added for many applications.
Another important change concerns the development of an alternate compliance path for computer-room systems.