For most local governments, improving energy efficiency is on a long list of facility needs. But a rapidly approaching federal deadline puts some teeth into those to-do lists – including a ruling that takes effect October 2013.
The nation’s top building energy codes and standards leave no doubt about the importance of conserving energy, and they outline specific areas in which lighting controls can accomplish this goal safely and effectively. Lighting accounts for about 40 percent of a commercial building’s electric bill, making lighting upgrades one of the most effective means of creating more efficient public buildings. They are also one of the simplest efficiency improvements, often accomplished with little disruption to daily operations or occupants.
The U.S. Department of Energy ruled in October 2011 that all states must reach or exceed the ASHRAE (American Society of Heating, Refrigerating, and Air-Conditioning Engineers) 90.1-2010 Standard for energy–efficient commercial building codes by October 18, 2013. With this mandate in mind, local and state government officials will need to consider their buildings’ energy use and what lighting controls strategies can be implemented to meet new standards.
Most states currently use ASHRAE 90.1-2007 or IECC (International Energy Conservation Code) 2009 as the basis for their building energy codes. California uses Title 24 Part 6, a state legislative code. The map below outlines which version of the ASHRAE 90.1 Standard (or equivalent) states have currently adopted. Maryland is the first state to adopt a state energy code equivalent to 90.1-2010. Other states will follow soon.
Mandatory Lighting Control Requirements
The ASHRAE 90.1, IECC and Title 24 Part 6 energy codes/standards all share key mandatory requirements that must be followed for new construction, additions, alterations, or renovations of commercial buildings. These requirements include manual and automatic lighting controls.
The standards dictate that any area enclosed by ceiling-height partitions must have an accessible, independent switching or control device (such as an occupancy sensor, manual switch, or dimmer) to control the general lighting. All indoor lighting systems must include a separate automatic shut-off control, such as an occupancy sensor or time switch (i.e. time clock).
Areas that receive direct daylight must have automatic and manual controls that allow lighting to be modified based on the daylight available in the space. Typically, a daylight sensor and dimming ballasts that control at least 50 percent of the general lighting power will meet this requirement.
Hotels, dorms, barracks or other lodging establishments must have a control at the entry that controls all the permanently installed lighting except those in the bathroom. Bathrooms must use an automatic lighting shut-off control (i.e. occupancy sensor) to turn lights off within 60 minutes of vacancy.
Most spaces must allow the occupants to select a lighting level that is between 30 percent and 70 percent of full power, in addition to OFF, by either continuous dimming, stepped dimming (dimming lights to certain, pre-defined light levels), or stepped switching (separately switching alternate lamps in a fixture or alternate luminaires in a space) while maintaining a reasonably uniform level of light throughout the controlled area.
Permanently installed outdoor lighting must be controlled by a daylight sensor or astronomical time switch that automatically turns off the lighting during daylight hours. In addition, 90.1-2010 requires certain exterior lighting to be automatically reduced by at least 30 percent when no activity is detected, or during nighttime hours.
Occupancy sensors used in most spaces must be manual-on or auto-on to no more than 50 percent lighting power. Occupancy sensors or count-down timers that turn off lighting within 30 minutes of vacancy are required in spaces not continuously in use such as conference and meeting rooms, lunch rooms, and storage and supply rooms.
In 90.1-2010, and coming soon to CA Title 24 2013, lighting in enclosed stairwells must have one or more control devices to automatically reduce lighting power by at least 50 percent within 30 minutes of vacancy.
The next generation of codes/standards will continue to push the envelope of energy efficiency and sustainability. Energy and green code requirements are becoming increasingly stringent. Requirements expected in the upcoming versions of building energy and green codes/standards include demand-responsive lighting, energy monitoring, emergency lighting control, and lighting quality requirements.
These requirements help our nation meet its energy conservation goals in a time when energy costs are rapidly increasing. Lighting controls play a vital role in meeting those requirements, and in turn, helping local and state governments save money by reducing their energy use.
About the Author
Michael Jouaneh is manager of sustainability and energy standards for Lutron Electronics, a designer and manufacturer of energy-saving lighting controls for residential and commercial applications. Mr. Jouaneh is active in the development of the nation’s top energy building codes/standards. He is a consultant to the ASHRAE 90.1 Lighting Subcommittee and a voting member of the ASHRAE 189.1, 100, and 90.2 committees.