A Green Stand

Standard 189.1, the Standard for the Design of High-Performance, Green Buildings Except Low-Rise Residential Buildings, published in late January by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), provides the first code-intended commercial green building standard in the United States.

Released jointly with the Illuminating Engineering Society and the U.S. Green Building Council (the creators of the Leadership in Energy and Environmental Design (LEED) green building rating system), ASHRAE 189.1 provides criteria by which a building can be considered green—that is, built and operated to a high standard of design sustainability. As with the ASHRAE 90.1 energy standard, 189.1 is not a code, although it can be adopted by governments as the basis for codes. It also is not a rating system, like LEED.

ASHRAE 189.1 is probably more likely to be adopted as a code for certain types of construction in jurisdictions currently requiring LEED certification. At press time, policies implemented by 34 states and 138 city governments referenced LEED. While the most ambitious policies require LEED certification for some private commercial buildings, LEED is generally required for public construction in these jurisdictions.

ASHRAE 189.1 covers the same building types as Standard 90.1 and includes the same building areas as LEED, including energy efficiency, site sustainability, water-use efficiency, indoor environmental quality, and the building’s impact on materials, resources and the atmosphere. The energy section is based on the 90.1 energy standard, but is more efficient than 90.1 2007, requires energy measurement for verification purposes, contains renewable-energy provisions and requires the capability to reduce peak-electricity demand. Overall, the goal is to achieve at least a 30 percent reduction in energy costs over 90.1 2007.

Lighting covered in Section 7.4.6, plays a major role in ASHRAE 189.1. This, in turn, is based on Section 9 of ASHRAE 90.1 with several significant additions and modifications to increase energy savings. The lighting power densities in 90.1, for example, are capped at 90 percent in 189.1. Most of the other changes involve more aggressive, mandatory use of automatic lighting controls.

The installation of occupancy sensors, for example, is mandated in a broader range of spaces, and manual-on operation is required unless an alternative is specifically allowed. ASHRAE 189.1 identifies a number of enclosed spaces where occupancy sensing is required, such as classrooms, small offices and conference and meeting rooms. In covered spaces, the sensor must provide manual-on/automatic-off operation, or instead of manual-on, the sensor can combine with a multilevel switching scheme and turn the lights on automatically to a lower lighting level; higher lighting levels require manual switching. ASHRAE 189.1 also requires occupancy sensors in spaces that often require continuous lighting, such as commercial and industrial storage stack areas, library stack areas, and hallways in hotels. In these spaces, the sensor must be installed with a multilevel switching or dimming system that reduces lighting power by at least 50 percent when the spaces are unoccupied.

Egress and security lighting that must be operated 24/7 is capped at 0.1 watts per square foot, but additional lighting can be installed as long as it is controlled by an automatic-shutoff device.

Continuous dimming or stepped-switching automatic daylight harvesting controls are required for daylight zones, under skylights or next to vertical fenestrations that combine in each enclosed space to exceed 250 square feet. The beginning of ASHRAE 189.1 defines these daylight zones. Other standards—such as the 2009 International Energy Conservation Code (IECC), California’s Title 24 energy-efficiency standard and the upcoming 90.1 2010—will require daylight harvesting, but ASHRAE 189.1 is aggressive in that it requires automatic lighting control instead of merely separate zoning. There are many exceptions to this requirement, such as window display and exhibition lighting, hotel guest room lights, and conference room lighting operated by local dimming controls.

Outdoor lighting must comply with Section 9 of ASHRAE 90.1, but some applications—parking lots, building facades, garages and others—require either a motion sensor and photocontrol or automatic controls that reduce lighting power by at least 50 percent, with few exceptions.
Additionally, two other provisions of interest include submetering and demand response. Section requires submetering of lighting if the connected load is greater than 50 kilovolt-amperes. Section requires the building to contain automatic systems capable of reducing peak electric demand by at least 10 percent, not including standby power generation, which may involve automatic shutoff and dimming of lighting systems.

California recently passed CALGreen, a state green building code, which will apply to new commercial buildings starting January 2011. And the International Code Council, creator of the IECC, is expected to announce publication of the International Green Construction Code standard in 2012, when the next version of IECC will be released.

Visit www.ashrae.org for more information on ASHRAE’s standard 189.1.

DILOUIE, a lighting industry journalist, analyst and marketing consultant, is principal of ZING Communications. He can be reached at www.zinginc.com.

About the Author

Craig DiLouie

Lighting Columnist
Craig DiLouie, L.C., is a journalist and educator specializing in the lighting industry. Learn more at ZINGinc.com and LightNOWblog.com .​

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