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Version 4 of the popular Leadership in Energy & Environmental Design (LEED) green building rating system is expected to be released at Greenbuild in November 2013.
Final balloting to approve the new LEED version is expected to occur in June, so we don’t know exactly what will be contained in the new rating system. One thing is almost certain, which is that the prerequisite for the Energy + Atmosphere section will change from the 2007 to the 2010 version of the ASHRAE/IES 90.1 energy standard.
This is because the 2010 version of 90.1 is now the national energy standard. By October 2013, all states in the country must put in place a commercial building energy code at least as stringent as ASHRAE/IES 90.1-2010 or justify why they can’t comply.
This standard is expected to be tough to beat in terms of both lighting power densities and controls. For controls, ASHRAE/IES 90.1-2010 requires automatic shutoff, bilevel lighting and daylight harvesting in a wide range of applications. These requirements are mandatory, meaning compliance translates to satisfying the LEED prerequisite.
What control options are available that can go beyond the prerequisite and earn LEED Energy + Atmosphere points?
The solution may be contained in the language of the standard. ASHRAE/IES 90.1-2010 contains mandatory control requirements (you have to do this) but also lists advanced control options that may be institute in exchange for a power credit (you do this, and you get more watts for the design as function of the control strategy and the size of the controlled loads).
The advanced control options, applicable to interior lighting systems, are found in Table 9.6.2 (applicable to the Space by Space design compliance method) and include:
• manual or programmable dimming control (must be combined with occupancy sensing in meeting and training spaces);
• multilevel occupancy sensors controlling the downlight component of workstation-specific luminaires with continuous dimming to OFF, which may be combined with occupant dimming of this downlight component;
• automatic bilevel or multilevel switching or continuous dimming daylight harvesting control in primary daylight zones under restrictive conditions related to effective aperture and size of zone; and
• automatic continuous dimming daylight harvesting control in secondary sidelighted daylight zones with a daylight aperture considered large enough.
Again, implementing these strategies above and beyond all applicable mandatory strategies is rewarded with a power adjustment credit using the following formula:
Additional Interior Lighting Power Allowance = Lighting Power Under Control (watts) x Control Factor (specific to the given control strategy by space type, from Table 9.6.2)
The control factor is specific to control strategy (manual dimming, etc.) and space type (open office, private office, meeting space and various public spaces). The factor ranges from 0.05 (manual dimming in a private office) to 0.30 (occupancy sensing controlling the downlight component of workstation-specific luminaires with continuous dimming to OFF combined with personal continuous dimming).
So if manual dimming is implemented to control a 1000W load in a retail sales area, resulting in a control factor of 0.10, 100W of additional lighting power is gained, which can be used by the designer anywhere within the building.
It’s a good addition to the code, as it provides additional options to achieve flexibility. It might also be useful for LEED. What if the additional lighting power was not claimed as additional lighting watts but instead as direct energy savings?
The Lighting Controls Association contacted the USGBC about this issue and received this reply:
“If a project is pursuing LEED certification using the building energy simulation option (modeling per ASHRAE 90.1-2010), and the optional lighting controls are installed, the additional lighting power allowance would be added to the baseline building lighting power allowance for that space. Any reduction from that value in the proposed building could be claimed as savings.”
The Lighting Controls Association has interpreted this to mean that Table 9.6.2 in ASHRAE/IES 90.1-2010 provides control options that can be used to either achieve additional lighting power using the Space by Space Method OR reduce energy consumption and thereby contribute to LEED Energy + Atmosphere points.
Suggested energy savings are built into the standard. In our above example, using manual dimming in a retail sales area to control a 1000W load would result in 100W of power savings that could be applied to LEED.
Again, this particular method of claiming energy savings would be applicable only to those projects that use the Space by Space Method of compliance.
This may be beneficial for designers of lighting systems in LEED projects, as it opens a range of lighting control strategies that can be enacted to exceed the minimum standard criteria and earn LEED Energy + Atmosphere points.
Schneider Electric offers a free whitepaper addressing measurement and verification of lighting systems.
Measurement and verification (M&V) defines a process used to track energy performance of equipment, systems and buildings, enabling evaluation and comparison. M&V plans have become an essential element in many LEED Projects as well as many public projects.
The whitepaper, authored by Scott Jordan, product manager for the LifeSpace Division of Schneider Electric, addresses the various types of M&V plans used to evaluate lighting systems, provided benefits and implementation of an M&V system.
Download it here.
ELECTRICAL CONTRACTOR has published an article by Craig DiLouie describing how to zone lighting control strategies and develop a control zone plan.
Check it out here.
ARCHITECTURAL LIGHTING has published a brief “one on one” interview with Eric Lind, Vice President of Global Specifications at Lutron Electronics
Check it out here.
In March 2012, the International Code Council
announced availability of the International Green Construction Code (IgCC), a model code for constructing and remodeling buildings to a higher sustainability standard.
The IgCC establishes a baseline for new and existing construction regarding energy efficiency, water efficiency, site impacts, building waste, material source efficiency and other sustainability measures, acting as an overlay to existing model codes such as the International Energy Conservation Code (IECC) and the ICC-700 National Green Building Standard.
A green building model code is sensible when one considers governments around the country are requiring a LEED rating for public construction. The IgCC provides a series of sustainability requirements in code language that is adoptable, usable and enforceable, and references ASHRAE 189.1 as an alternate compliance option. It is intended to complement rating systems like LEED. As of the time of writing, Florida, Maryland, North Carolina, Oregon and Rhode Island and a number of cities have adopted the IgCC in whole or in part.
What’s in it for lighting? How is the IgCC different than the IECC?
Electrical power and lighting systems in new construction and remodeling projects is covered in Section 608. The lighting aspects enhance compliance with the IECC. Most of these aspects are related to lighting controls.
Indoor and outdoor lighting systems that must remain operational even when the lighted area is unoccupied must be reduced to a step between full power and OFF to save energy during these unoccupied periods unless the application is specifically exempted. Alternately, outdoor lighting systems can be controlled by occupancy sensors or be self-powered (solar). Applications include corridors, enclosed stairwells, storage and stack areas not open to the public, parking garages, and all outdoor lighting within two hours of conclusion of facility operations.
Exterior façade, sign and landscape lighting, meanwhile, must be automatically turned OFF within one hour of facility operations stopping up until one hour of operations resuming. If facility operation is continuous, decorative building façade and landscape lighting must be turned off from midnight to 6:00 AM.
Automatic daylight harvesting controls and plug load controls are required in certain spaces. If the building is located in a region where a power provider offers a demand response program, and it does not produce its own onsite renewable energy to satisfy 20 percent or more of its electrical demand, then lighting in certain office spaces must be capable of reducing the total connected lighting load by at least 15 percent, with some exceptions (Section 604).
Light fixtures that use fuel gas, unless installed in a must be included in lighting power calculations using a formula converting BTU/hour into a wattage equivalent.
Section 409 covers “light pollution,” imposing a maximum outdoor system light level based on lighting zone, in turn based on population density; the higher the density, the higher the outdoor light level that is acceptable. Additionally, maximum backlight, uplight and glare ratings for outdoor light fixtures are assigned for each outdoor lighting zone.
The building must be metered (with individual metering per tenant in tenant-occupied buildings), per Section 603. The information must be collected and reported, with a category for interior and exterior lighting used in occupant spaces and common areas.
Section 506 requires low-mercury lamps, with some specialty lamps being exempted. Linear bi-pin fluorescent lamps are limited to 5mg of mercury per lamp; long-life lamps are limited to 8mg. Pin- and screw-based compact fluorescent lamps are limited to 5-6mg per lamp depending on wattage.
Section 808 presents extensive requirements for daylighting.
Chapter 9 covers commissioning, with additional requirements in Section 608. Before the certificate of occupancy is issued, a field inspection must be conducted to verify that all lamps, ballasts and lighting controls are installed in accordance with approved construction documents. The lamps must be re-verified at 18-24 months of post occupancy. Site lighting must be verified as complying with Section 409. Lighting controls must be calibrated by the system installer or commissioning agent, and re-calibrated at 18-24 months. Operations and maintenance documentation must be turned over to the owner for all lighting systems, including technical inspections, manuals, fixture relamping and cleaning plan, lamp disposal information, and programmable and automatic controls documentation (including final settings).
Chapter 10 covers existing buildings. The current language of the code as of the time of writing required daylight harvesting controls in daylight zones. Additionally, exterior lighting shutoff must use either a time switch or a combination of a photosensor and a time switch.
Appendix A provides a list of advanced electives that jurisdictions can implement for more aggressive levels of sustainability. For example, in one option available to jurisdictions, lighting power densities must be realized that are at least 10 percent lower than in the IECC.
Craig DiLouie, LC recently interviewed Mike Crane, product manager for Hubbell Building Automation, for ELECTRICAL CONTRACTOR on the topic of wireless RF lighting control. The interview is published here in its raw form.
DiLouie Please describe what wireless RF lighting control is, how it works, and its intended purpose.
Crane: Wireless RF lighting control is the ability to turn lighting on/off and dim to a specific level remotely over the air using radio technology. Actuator devices, which contain relays for turning the lighting on and off, are wired directly to a fixture or lighting circuit. Input device, such as a switch, occupancy sensor or daylight sensor send commands over the air via radio signals to the actuator who then responds to the command accordingly. These commands typically tell the actuator to close or open its relay and if it does dimming, to what level the lighting should be set to.
DiLouie: How would you describe the history of wireless RF lighting control’s evolution over the past 10 years? Where did we start? What key changes occurred in the technology/market allowing progress? Where are we now? Where are we headed?
Crane: Wireless RF lighting controls primarily got its start in the residential market. Over the last few years, the interest in wireless lighting controls in the commercial market has seen a major increase, primarily due to changes in new energy codes and regulations like ASRAE/IESNA 90.1, California Energy Commission (CEC) Title 24, USGBC LEED (Leadership in Energy and Environmental Design) and International Energy Conservation Code (IECC). These code changes are requiring the use of energy saving lighting controls. With the creation of robust and reliable radio-based technologies like Zigbee, EnOcean and SNAP, developing and providing commercial solutions is now possible. Although the technology has been around for a while, we are still at the very early stages of adoption within the commercial market. There is a now a growing number of wireless lighting control providers today which provide niche solutions (e.g. parking garages, outdoor lighting only, indoor only, etc.). As the technology becomes more pervasive in the commercial market, major manufacturers will focus on being “one stop shops” by providing complete solutions for all lighting applications – indoors and outdoors. These bundled solutions will include all forms of luminaries with wireless controls built in.
DiLouie: What are the benefits of wireless RF lighting control? What opportunities do these benefits create for electrical contractors?
Crane: Wireless RF lighting controls provide many benefits. They can be easily added to existing lighting systems wherever needed without having to worry about changing existing wiring. This is especially important when dealing with the wiring challenges associated with hard ceilings or outdoor lighting. Another benefit is flexibility. Wireless lighting controls provide the ability to configure and fine tune lighting at anytime based on the customer’s lighting and control requirements. Wireless controls also eliminate the need for expensive dedicated low voltage control communications wiring. Wireless lighting controls not only provide benefits to the end user, they also create an opportunity for the electrical contractor for commissioning services. Once wireless lighting controls are installed, they typically need to be programmed or commissioned. This involves the pairing of actuators with input devices. This programming is sometimes done physically on the device or via software. Electrical contractors who are knowledgeable in the various wireless lighting controls can expand upon their services by offering system commissioning.
DiLouie: What are the different approaches to wireless RF lighting control (fixed, mesh, etc.) and what are the pros and cons of each? What elements do most manufacturers share and where do they commonly diverge into different approaches?
Crane: The two most popular approaches are fixed-based and mesh-based systems. Fixed systems typically pair actuators directly to input devices. They are typically in close proximity to one another. Mesh-based systems also pair actuators with input devices and also support the ability to route and repeat messages throughout the network – ensuring that the originating node’s messages gets to the target node. By having each device be a repeater, mesh-based systems provide the ability to have a large network of devices. The pros and cons of each all depend on what the lighting application is. If all you need to do is control a single room with an actuator and a switch, then fixed based controls may be all that you need. If you want to change configurations over the air, or control lighting based on schedules, or control all the devices from a central location or remotely over the Internet, then a mesh-based system may be the appropriate solution. The pairing of actuators with input devices is the element that most manufacturers share since it’s required for both fixed and mesh based systems. Where they tend to diverge is on the type of approach – fixed or mesh. Hubbell Building Automation offers both mesh-based and fixed-based wireless control solutions for a variety of lighting applications.
DiLouie: What have been the biggest changes or advances in wireless RF lighting control over the past 2-3 years, and how has this influenced offerings and adoption of wireless control?
Crane: With the growth of wireless technology in general (e.g. cell phones, wireless home phones, wireless Wi-Fi routers), the cost of radio technology has now reached a point where it is affordable to manufacture wireless lighting control products and not destroy the overall return on investment of the luminaries with controls. Also, lighting unlike other building systems (e.g. HVAC) requires immediate response times. Users are okay with waiting 5-10 minutes for the heat to turn on after adjusting a thermostat, but will not wait for lighting to turn on or off after a light switch has been pressed. Improvements in the various wireless control protocols to address lighting’s requirement for quick response times has also been an influence in the ability to provide suitable offerings.
DiLouie: How are these systems installed and set up? What do contractors need to know?
Crane: Typically, the contractor will install an actuator either in or on a fixture or junction box. The hot will go to the actuator, neutral to both the actuator and the fixture, and the actuator’s switch leg will go to the hot on the fixture. Battery or energy harvesting input devices are typically mounted where they normally would be. If this is a fixed based system the contractor will typically put the actuator into a “learn” mode and then pair it to the switch by pressing the switch. For meshed-based systems the actuators are typically wired up the same way. Meshed-based input devices may be battery operated or powered via a power-pack. Software running on a laptop or PC is then used to communicate to an access point or gateway device which discovers and pairs devices.
DiLouie: Wireless lighting control networks appear to be covering bigger commercial applications than before. What lessons has the industry learned about applying wireless lighting control to large applications?
Crane: Wireless systems have to have devices that can repeat messages and route them via different paths. This ensures that messages will still get to their target destination, even if one or more paths may be unavailable for whatever reason (e.g. an inoperable node in a path). Another lesson learned is that large wireless lighting applications need a way to uniquely identify each device and addressing dip switches or knobs is definitely NOT the way to go. They are limited to the number of addresses they can support which in turn limits the number of luminaries and input devices supported. There are now wireless protocols that support unique addresses associated with each radio. This provides the ability to support large networks. As long as one device is in range of other devices, it can participate in the network…no matter what the size of the network is.
DiLouie: The most common protocols governing design of wireless RF lighting control products appear to be Zigbee, Z-Wave and EnOcean plus various proprietary protocols. What are the pros and cons of these approaches? What are ideal applications? Are there any other protocols of note?
Crane: Another protocol of note is SNAP (Synapse Network Appliance Protocol). Like Zigbee, the SNAP protocol provides the infrastructure to create peer-to-peer, self organizing and self healing mesh networks. The major difference between Zigbee and SNAP is that SNAP supports 900MHz radios while Zigbee supports 2.4GHz radios. The major difference being that for 900MHz provides almost twice the radio coverage and is least affected propagation losses due to penetration through obstacles, diffraction and reflection. The SNAP protocol also does not require a coordinator (potential single point of failure) like Zigbee does.
DiLouie: The ideal control solution for a given building may require a mix of wired and wireless lighting control solutions, and wireless lighting control integrated with other building control systems. What questions do designers need to ask to ensure that all components talk to each other properly? What’s needed?
Crane: Can this system communicate with other building control systems? If so, how is the integration accomplished? What building management system protocols are supported? Bacnet? Modbus? Lon? Does the system provide an input/output interface for other devices (e.g. motorized window shades)?
DiLouie: Integrated lighting control appears to have strong potential for LED lighting systems. Does wireless RF lighting control have any particularly suitability with LED lighting compared to wired control methods?
Crane: Yes. As the cost of energy continues to escalate, the value of indoor and outdoor lighting solutions which capitalize on both energy efficient LED lighting technologies and aggressive energy saving control strategies, continues to grow. For example, with solutions available from Hubbell Lighting today, outdoor LED lighting with integrated wireless control can be programmed over the air to dim down to a certain level at a specific time, and then dim even further throughout the evening – saving energy and reducing light pollution. If the lighting ever needs to be manually changed, a user can easily send a wireless command (via a wireless switch or through their Internet web browser) to the LED lighting to immediately adjust to a new level.
DiLouie: If you could tell all electrical contractors only one thing about the wireless RF lighting control, what would it be?
Crane: When working with mesh-based systems that have unique addresses for each device, it’s imperative that the address information provided with each device is not discarded, but properly recorded on site plans or as-builts. Having this information available is key to the successful commissioning of the system.
Special thanks for Mike Crane.
AMERICAN SCHOOL & UNIVERSITY recently published an article by Anne Hildenbrand, AIA, LEED AP, and Lisa Lamkin, AIA, CSI, LEED AP of BRW Architects, who described their work on John T. White Elementary School, the first school in the Fort Worth (Texas) district to be verified as a High Performance School by the Collaborative for High Performance Schools (CHPS). Its design harvests daylight, provides multiple lighting controls for the teacher, and achieves an overall higher quality of lighting.
Read it here.
In an article recently published by CONSULTING-SPECIFYING ENGINEER, Scott Ziegenfus, senior applications engineer with Lutron Electronics, defines a role for lighting in demand response strategies. Check it out here
Demand for electricity in the United States has gone up in all but four years since 1949. The Department of Energy predicts growth in capacity of 0.6% per year through the year 2040.
Many states and utilities have long considered energy efficiency a resource for satisfying growing demand. According to a study by the American Council for an Energy-Efficient Economy, saving a kWh through an energy efficiency program costs about 2.5 cents, about a third of the cost of building new capacity. DOE expects end-use energy efficiency and demand response to reduce peak demand for power by 5% over the next 10 years. Lighting controls will play a major part of these efficiency improvements as well as demand response.
Spending on energy efficiency programs has been increasing dramatically in recent years in the U.S. and Canada. Commercial and industrial electric programs have traditionally run about 35% of total spending, so that would be about $3 billion spent in 2011.
US and Canadian Efficiency Program Budgets 2007-2011. Consortium for Energy Efficiency. State of the Efficiency Program Industry: Budgets, Expenditures, and Impacts 2011. http://www.cee1.org/annual-industry-reports, posted March 2012. © Copyright 2012 Consortium for Energy Efficiency. All rights reserved.
A key component of these energy efficiency programs is the rebate. You agree to install a product that satisfies certain performance criteria, and you get a check to reduce the initial cost and make that product more attractive to install. According to BriteSwitch, more than 70% of the U.S. is covered by an active rebate program covering commercial lighting.
The prescriptive product rebate remains the most popular type of rebate. This is a cash rebate promoting specific qualifying lighting upgrade options. The amount of the incentive varies widely, with the average rebate improving payback by up to 20-25%, making these technologies more attractive for owner investment by reducing initial cost.
The two major trends in rebates are coverage of LED products and lighting controls, says Leendert Jan Enthoven, president of BriteSwitch.
Regarding lighting controls, controls are now common in rebate programs, with the number of rebate programs almost tripling since 2009. “For control rebates, there is still a great opportunity across the country for many different types of technologies,” says Enthoven.
The most popular control rebates are remote-, wallbox- and fixture-mounted occupancy sensors, photosensors and dimming daylight harvesting systems (see table below). The actual rebate earned may depend on whether the project is new or existing construction. The controls may be required to be listed by UL or other OSHA-approved testing laboratory.
|Remote Mounted Occupancy Sensors
|| $ 34.54
|| $ 25.22
|Wall-box Occupancy Sensors
|| $ 24.17
|| $ 14.37
|| $ 28.49
|| $ 33.24
|Fixture Mounted Occupancy Sensors
|| $ 20.00
|| $ 26.17
|Daylight Dimming Systems
|| $ 45.79
|| $ 41.67
“The biggest shift we notice is that many rebate programs are starting to rewrite their program guidelines to allow wireless sensor technology,” Enthoven says. “Previously, many programs excluded wireless sensors, but as the technology has advanced and many reputable control manufacturers introduced quality products, the programs have started to adapt.”
For a list of rebates and other energy incentives available across the United States, click here.
Pre-approval is often required before equipment is purchased, a process that can take as long as about a month. Enthoven adds it can take up to 120 days or longer for the rebate check to be delivered. Because strong participation is draining program funds earlier in the year in some regions, check with the utility that funding will be sufficient to ensure promised rebates will be delivered.
Dr. Ian Rowbottom of Lutron Electronics authored a whitepaper on the Lutron website titled, “Building Dimmers Vs. Building Power Plants.”
Using simple math, he makes a case that while it costs $1.40-$7.75 to build a watt of electric generating capacity, it costs only about $0.35 to remove a watt with a dimmer.
He writes, “At 35¢/Watt, it is far cheaper to conserve electricity with dimmers than it is to install new power generating equipment. Another advantage: Dimmers are available immediately and can be installed on the same day of purchase, whereas it can take decades to plan and build a power generating plant.”
Get it here.