Consistent, scheduled revisions to national model codes are designed to keep pace with changing construction practices, incorporate new technologies, and improve building efficiency. Standards-writing organizations publish energy standards on a multi-year cycle. States and municipalities subsequently adopt these standards into law at different times. Beyond that, the requirements are typically different for renovations versus new construction and can also change by building and space type.
Because energy codes are complex, it can be difficult to stay informed, especially with projects that reach across broad geographic areas or include a variety of building types. Specifiers and contractors are tasked with ensuring lighting control systems are code-compliant and still meet demanding occupant-performance requirements, but this can be challenging.
These seven questions provide answers that help ease the process of implementing code-compliant lighting and control solutions that meet customers’ needs and budget requirements without sacrificing performance essential to reducing energy use, increasing occupant comfort, and improving space use. Answers address common points of confusion, provide strategies for meeting code on every project, and identify ways to take advantage of resources that will help clarify code requirements.
1. Which energy code applies to my project? Prior to occupancy, all buildings must meet the energy code that has been adopted by the local authority having jurisdiction (AHJ). Energy standards, such as ASHRAE 90.1: “Energy Standard for Buildings Except Low-Rise Residential Buildings and the International Energy Conservation Code” (IECC), are developed nationally on a three-year cycle. Most state codes are based on these standards. California is the exception to this rule, as it uses the “California Title 24 Part 6 Building Energy Efficiency Standard” in a concerted effort to ensure buildings achieve a very high level of energy efficiency and preserve outdoor and indoor environmental quality. California is pushing toward zero net energy by 2020 for residential buildings and 2030 for commercial buildings.
States must adopt a minimum code standard, but they also have the option of adopting and making amendments to these standards. Local jurisdictions within each state must generally adopt the state’s code while having the option of amending that code prior to adoption — provided it is at least as energy-efficient as the state code. Given the multiple editions of IECC in existence today, coupled with the opportunity for states and AHJs to amend their codes, keeping track of specific requirements can be difficult.
Code information is generally available online at the IECC and ASHRAE websites, but more targeted energy code look-up tools are available through manufacturers’ websites to find state or local energy codes.
2. How do I know if a certain product complies with energy code requirements? Individual products are not certified to meet building energy codes. Energy codes require specific functionality, depending on space type, daylight availability, and whether or not the space is illuminated and intended for use as a means of egress during an emergency. The correct product application in buildings, rather than the products themselves, deliver the necessary functionality to comply with energy codes.
Typical required lighting control functions include scheduled or automatic shutoff, multilevel, and daylight-responsive. One product or group of products can be installed and programmed in accordance with a defined sequence of operations to meet the functional code requirements for each space.
3. How do retrofits differ from new construction in terms of code compliance? Project scope changes code requirements. New construction will always have the most stringent energy code requirements. Retrofits often have fewer requirements, but the threshold for including energy-savings strategies is different within each code.
Energy code requirements for lighting alterations or “retrofits” vary, depending on the adopted code and the scope of the retrofit. Projects in which only a small number of luminaires are replaced typically do not need to meet any additional control requirements. The exact percentage varies in each energy code, but replacing a higher percentage of luminaires makes it more likely the project will have to meet updated code control requirements.
New construction codes may have to be met in projects that either include replacement of all luminaires or involve the relocation of walls or partitions. Check local energy codes for the precise limits on lighting alterations and the associated lighting control requirements.
Using digital ballasts or drivers along with wireless sensors and controls can make future lighting retrofits and rezoning of lighting in a space easier and faster. Consider approaching each retrofit with future updates in mind.
4. Is there an advantage to occupancy-based control versus timeclock control? Timeclock (also known as time switch) control automatically turns off the lights in a space when that space is normally unoccupied, such as during nighttime hours. This is most useful in areas that conform to a prescribed schedule. An occupancy sensor is a device that automatically reduces or turns off the lights in a space after all occupants have left that space. As long as the space is occupied, the lights remain on.
In most energy codes, the baseline requirement is scheduled shutoff (timeclock), but occupancy sensors can also meet this requirement in most applications, and some of the newer codes require occupancy sensors in certain space types. If the code allows an option, consider the strategy that best meets the immediate and long-term needs of the space. In certain spaces, some energy codes also require automatic shutoff for half of the 120V receptacles. Occupancy sensors and timeclocks that control the lighting can also be paired with receptacles to make it easier to meet any automatic receptacle shutoff requirements. The same occupancy sensors that control lighting and receptacles can also control HVAC systems. This is typically done in hotel guest rooms where the latest energy codes require automatic shutoff of lights and receptacles as well as automatic stepdown or step-up of the thermostat in the guest room while it is vacant.
5. What fixture/control strategies can be used to meet daylighting requirements? Daylight code requirements are typically defined per daylight zones, and daylight zones generally fall into one of two categories: sidelight or toplight. Sidelight zones are adjacent to windows and are typically based on window height (distance from the top of the window to the floor). Toplight zones are under skylights and defined based on ceiling height. In each case, the location of obstructions, such as partitions, change the daylight zone area.
Exceptions to the daylighting requirements also exist based on total lighting power in all daylight zones in a space and window surface area. While the daylight control requirements promote the use of natural daylight in a space, they don’t address glare and heat gain — factors that can inhibit productivity by reducing occupant comfort. Using automated shading systems and appropriate fabrics can help preserve the benefits of daylight while controlling the amount of glare and heat entering a space as a result of direct sun exposure.
6. Are manual controls required for occupant safety? Manual or “local” controls are required in most spaces, but exceptions, such as the ability to mount the manual control in a remote location or to waive the requirement altogether, do exist, depending on the code and the space. These exceptions most often occur in spaces that may be used as means of egress or where constant illumination is required. Always check the local code for exceptions to the manual control requirements, since they vary widely.
7. What if I still need help determining which requirements I need to meet? Various manufacturers and industry organizations provide reference materials, and local training sessions are sometimes offered as well. For general information about building energy codes and standards, visit www.energycodes.gov. If further interpretation or clarification need to be made for a project, directly contacting your state’s building department is another option.
Solutions for code compliance and best practices. Designing a building or space that meets code is a basic requirement. As a designer/installer, it’s important to offer alternative solutions that go beyond minimum compliance and identify best practices and solutions that promote well-being and best serve the various needs of the people in the space. No single resource can guarantee a code-compliant solution, so it’s essential to verify selected control strategies with a local AHJ for energy code amendments.
Casey is a senior building science engineer with Lutron Electronics Co., Inc. in Coopersburg, Pa. He is active in the Illuminating Engineering Society’s (IES) Energy Management Lighting Controls Subcommittee. He can be reached at [email protected].
