Optimized Solutions for Lighting – Today and for the Future
By Ed Novak, CFM SFP
Shedding a Little Light / Background
It wasn’t that long ago that lighting controls simply consisted of a switch to turn a light or a set of lights on and off. Title 24 has been with us for a while with the first California Energy Commission standards for energy conservation released in 1978. The 2008 Building Energy Efficiency Standards are the current standards for lighting controls, which have been in effect since January 1, 2010. Section 131 of the standard requires that all indoor lighting systems be equipped with separate automatic controls to shut off lighting: you can’t just have a physical switch anymore. In addition, the interior lighting for commercial spaces must also have:
- Automatic Time Switch Control Devices
- Occupant Sensors, Motion Sensors, or Vacancy Sensors
While everyone supports improved energy efficiency, most of us would rather not have to pay the extra costs that the regulations mandate with new construction. The additional costs for complying with the minimum requirements to meet Title 24 have not always added the same amount or more value in energy efficiency that most investors would find acceptable.
Before I get into that, let’s review the recent history of lighting controls technology. The First generation of automated lighting controls consisted primarily of a “Building Sweep” technology with added circuit-level timers to ensure the lights were off after hours. The timer had a set time and did not have the sense to know if anybody was in the building. These systems no longer meet current Title 24 requirements.
The Second generation of lighting controls (“Occupancy and Daylight Detection”) attempted to solve these weaknesses by providing room-level occupancy sensors. This strategy did a better job with private offices but did little to improve the energy efficiency in open floor plans and could not respond to individual preferences.
Lighting technology with “Zone Level Sensing with Centralized Network Controls” was introduced in the Third generation systems, which attempted to improve the granularity of control by providing for addressable fixtures but did so with some significant limitations. Extensive design and commissioning are required to implement these systems correctly, thus rendering it an expensive option. In addition, they use zone-based sensors which are incapable of responding to true lighting needs and thus provide limited savings. These systems require centralized control thereby relying on an operable network for daily operations.
Now a Fourth generation in lighting management exists, which consists of autonomous sensors wirelessly connected to a flexible control system. Deploying addressable sensors that collect real-time occupancy, ambient light, and temperature information and autonomously control fixture behavior based on those readings for every fixture in the building creates a building system that provide detailed information about the operation of every square foot of the building and control of every light within it.
Why just complying with Title 24 isn’t good enough
When designing space for a new project, we as facility managers have to make numerous choices about the design, including the building infrastructure. When it comes to lighting controls, you don’t need to install a Fourth generation system, you can still get by with a Second generation system that will meet the minimum requirements for Title 24. So, why would you want to go beyond the minimal requirements? There are several reasons, including:
- Additional Energy and Cost Savings – 60% to 70% is achievable. See Figure 1 on how an advanced lighting controls system can save energy and money.
- The ability to mine real-time ambient light, motion, and temperature readings from every light fixture and deploy it to other energy services and systems including HVAC, demand response, and security systems
- Easier implementation when zero design is required and wireless devices are installed
- A more sustainable solution that will maximize occupant productivity, comfort, and safety plus qualify for additional LEED points.
Recently, a technology company was developing plans for a new approximately 100K SF facility and the design team had specified a typical Title 24 Minimum Requirements lighting controls system. Once the facility manager became aware of the technological advantages of a 4th Generation system, he asked for a proposal and a cost comparison between the two options.
While the 4th Generation system would cost approximately 10% more (after rebates and federal tax credits) it is the better option because it will:
- Increase Operating Profits for the company because the payback from energy savings is less than one year payback compared to the Title 24 minimum system
- Improve Cash Flow after Year 1 because the energy savings for every year is greater than the additional cost of the 4th Generation system
- Result in a Higher Quality Work Environment by providing the facilities organization with greater lighting control, resulting in increased comfort and flexibility for building occupants. This can result in higher productivity as well as higher attraction and retention of talent
- Increase the number of points that they were seeking for LEED certification
Where the Savings are – typical breakdown on how an advanced lighting control system can save energy and money versus a system that just meets Title 24 minimum requirements shows that:
- 40% to 50%. is via Occupancy Control
- 30% to 40% is via Task Tuning
- 10% is via Daylight Harvesting
- 10% is via Lumen Maintenance
Note – actual saving amounts vary by building.
Title 24 changes for 2014
More changes to Title 24 are coming. California’s new Building Energy Efficiency Standards take effect in 2014. They make nonresidential buildings 30 percent more efficient than the current 2008 standards.
Adaptive lighting—lighting that automatically dims or shuts off when it’s not needed—represents one of the largest near-term opportunities for energy savings, and its inclusion in the state’s building code marks vital progress. The California Energy Commission projects the non-residential standards alone will save the state 372 GWh every year. Hopefully, they will also pave the way for other states pursuing climate goals.
In all enclosed areas larger than 100 SF, installed luminaires will need to meet the following requirements:
- Multi-level lighting control: Each luminaire must have either at least four steps of control, or continuous dimming, depending on the lamp type – simple on/off switches will no longer be allowed.
- Have at least one of the following types of controls for each luminaire:
- Manual continuous dimming and on/off control
- Lumen maintenance, a strategy used to provide a precise, constant level of lighting from a lighting system
- Tuning, the ability to set maximum light levels at a lower level than full lighting power.
- Automatic daylighting controls, which sense increased levels of ambient light and automatically dim luniaires
- Demand responsive controls
In addition, offices less than 250 SF, conference rooms, and classrooms, Vacancy Sensors will now be required instead of Occupancy Sensors. Vacancy sensors must be manually turned on, whereas an Occupancy Sensor will turn itself on the moment it senses motion. Once lights under either Occupancy Sensor or Vacancy Sensor control are on the sensors will sense motion and will time out and shut off when motion is no longer sensed.
The new codes also require more extensive daylight harvesting controls, which must be implemented into virtually every office or commercial space with skylights or windows. In addition to connecting all skylit luminaires to fully functional automatic daylighting controls, all primary sidelit lumniaes must also be controlled, up from half in the 2008 codes. These controls must leverage the multi-level control steps mandated for all luminaires.
One of the most sweeping changes in the 2013 codes is the requirement to install granular lighting controls in parking garage areas. For the first time these spaces, which have traditionally run their lighting 24 hours per day, 7 days per week, will be required to install occupancy sensors with three control steps, and with no more than 500 watts of connected load per sensor. In addition, garages with more than 36 square feet of glazing or opening must equip luminaires in the primary and side lit daylight zones with automatic daylight controls. Finally, parking garages’ allowable lighting power density has been reduced by 30%, from .3 watts per square foot to .2 watts per square foot.
Most retrofit projects will be required to meet new-construction standards for both lighting power density (LPD) and controls. The only exceptions are projects replacing fewer than 40 ballasts or which will address less than 10% of the luminaires in an enclosed space.
Lighting controls technology continues to evolve along with the requirements mandated by Title 24. As a facilities manager, you need to make sure that you stay abreast of these changes to ensure that you make the best choices for your employees and other stakeholders of your facilities. Just meeting the minimum requirements for Title 24 is usually not the best choice even if it may have the lowest first costs.
When considering capital projects, you should always find answers to questions that affect the Triple Bottom Line:
- How will each option effect / benefit the occupants of the facility?
- Which options are best for the environment, particularly those that reduce or eliminate waste and excess use of resources?
- When looking at the options from an investment point of view, what are the expected rates of return for each option?
Lastly, your vendors and peers can help you, but you may need to press them for more information. Don’t just accept a design choice because “that’s the way we’ve always done it”. Find out why someone may be recommending one option instead of another. Do some research on the options: check references, obtain financial comparisons between options and meet with lighting controls company leaders to find out about future development plans that may provide you with additional rewards down the road.