Lighting Trends: Lighting Controls Update
By Anne Cosgrove
From the April 2014 issue of Today’s Facility Manager
In the U.S., building energy codes are the jurisdiction of each state, and while some have developed their own codes, the federal government requires a minimum standard—ANSI/ASHRAE/IESNA Standard 90.1, Energy Standard for Buildings Except Low-Rise Residential Buildings. Currently a joint effort of ASHRAE and IESNA (Illuminating Engineering Society of North America), an updated version of this standard was published in October 2013. Revisions feature a host of HVAC and building envelope requirements as well as changes to lighting requirements aimed at increasing energy efficiency of commercial buildings while maintaining quality light for occupants.
“While many things have changed since the first version of Standard 90 was published in 1975, the need to reduce building energy use and cost has not,” commented Steve Skalko, chair of the committee that wrote the 2013 standard. “This standard represents many advances over the 2010 standard, as we worked toward our goal of making [it] 40% to 50% more stringent than the 2004 standard.”
This latest version of ASHRAE 90.1 incorporates 110 addenda, reflecting changes made through the public review process. These changes include improvements to daylighting and daylighting controls, space by space lighting power density (LPD) limits, thresholds for toplighting and revised controls requirements and format.
LPD is a lighting power requirement that technically represents the load of any lighting equipment in a defined area, or the watts per square foot of the lighting equipment. It is often associated with the lighting power allowance (LPA) permitted by the building energy code in question.
“Achieving the stringency goals established for the 2013 standard presented a challenge in reducing the requirements for lighting,” noted Rita Harrold, director of technology for the IESNA. “While interior [LPDs] were re-evaluated and most lowered, there continues to be an ongoing concern about maintaining quality of lighting installations for occupant satisfaction and comfort while achieving energy savings. The focus in the 2013 standard, therefore, was not just on lowering LPDs but on finding ways to achieve savings by adding more controls and daylighting requirements as well as including lighting limits for exterior applications based on jurisdictional zoning.”
Meanwhile, the International Code Council (ICC) has updated its International Energy Conservation Code (IECC). The last version, 2012 IECC, introduced new mandates for manual and automatic controls of electric lighting and daylighting. Specifically, it required occupancy sensors in classrooms, conference and meeting rooms, private offices, restrooms, and other enclosed spaces.
Set for release in June 2014, the 2015 IECC will increase the mandatory installation of occupancy sensors and daylighting controls to many new types of spaces in areas not covered by the 2012 IECC, including warehouses and lounge rooms.
Title 24 Updates In California
Meanwhile, building professionals in California are gearing up for changes to the state’s Title 24 building code. Scheduled to take effect on July 1 of this year, the changes represent a revamped and more aggressive energy code. California’s Title 24 has been noted in the past for setting the pace for energy codes in other states, and the 2013 updates include several potent new lighting code requirements.
Central to the updated code is a new multi-level general lighting requirement. The new requirement for spaces over 100 square feet and .5 watt per square feet is sweeping, and dependent on specific lamp types. The new code mandates automatic daylighting controls whenever there is more than 120 watts of general lighting in primary, sidelit, or skylit daylight zones.
The new code also mandates that all buildings 10,000 square feet or larger be equipped with control systems capable of taking part in demand response programs. These buildings are required to be able to shed 15% of the total load.
Title 24 contains changes related to daylighting strategies as well. For instance, the code states that when LED fixtures are used for general lighting in these spaces, the luminaires must be dimmable from 10% to 100%. (To read more about LED developments, see the article below.)
Conditions set on specific facility types include those related to hotels and multifamily buildings; warehouses and libraries; and parking garages. For instance, occupancy sensors will now be required in corridors and stairwells of lodging facilities and multifamily buildings. The code also calls for occupancy sensors in warehouse aisleways and open spaces and stack aisles in libraries. Parking garages will now have to install occupancy sensors and daylighting controls.
And while it is sometime a pacesetter in the energy code arena, the revised Title 24 is now matching ASHRAE 90.1 in the area of compliance thresholds, with a mandatory controls trigger at only 10% of the fixtures in the space. The new code also includes metering requirements based on the size of a building’s electrical service, at the largest sizes requiring disaggregation of multiple types of electrical loads—including plug load, lighting, HVAC, water pumps, theatrical, commercial kitchens, elevators, and charging stations for electric vehicles.
Planning The Next Project
With the increased focus on controls as a means to help reduce the energy consumed by lighting in commercial facilities, many facility managers will be evaluating their systems to ascertain where and how to tackle lighting upgrades. Taking a look at a survey of TFM readers in early 2013, many facilities have controls systems in place; however, there is vast room for expansion on that front.
In the survey, 78% of respondents indicated they managed commercial or institutional facilities, and 13% managed manufacturing plants. Retail and other industries (e.g., worship, financial, arts/cultural) were also represented. In terms of square footage, 76% of respondents managed more than 50,000 square feet of interior space (28.4% of those overseeing more than 500,000 square feet), and 71% were working with buildings older than 15 years, with 38% of that group managing facilities older than 30 years.
More than half (59%) of survey respondents indicated they employed a “lighting management system” at their facilities. However, nearly three-quarters (70%) were using more sophisticated lighting control strategies (e.g., multi-level switching and continuous dimming) in less than 25% of their spaces. The types of controls cited were: motion sensors (71%); time switches (52%); and daylighting controls (35%). And 27% reported using a building automation system with integrated lighting controls.
The chart below is a snapshot of the types of lighting controls survey respondents indicated they were using in their facilities.
Todd D. Smith, head of value added services for SYLVANIA Lighting Services, says, “While developing standards and codes are delivering much deeper savings to the facility manager and end user, it must also be recognized that the cost to achieve these savings will increase. Standards and requirements for LPD and control strategies require an increasing amount of sophistication in the design and implementation of a retrofit strategy for any given space.”
Whether motivated by mandates or an internal goals, new and retrofit lighting projects will continue to focus on decreased energy usage while maintaining or even improving light quality for occupants.
Smith advises, “Facility managers and specifiers will want to ensure they are using lighting solutions providers with the capabilities and experience to provide the lighting and control system design analysis to deliver code compliant solutions at the best possible cost to the end user.”
There are a number of ways lighting controls can be implemented, and the specific approach impacts the level of energy savings that will be achieved. Whatever path facility professionals take in approaching these projects—whether in new or retrofit applications, researching the technologies and learning about the actual return on investment are important factors. And, with the latest updates to energy standards and codes the time to seek out answers is fast approaching.