Commissioning lighting systems
The complexity of lighting design has made commissioning of lighting controls an essential part of projects. Commissioning for the most part is voluntary; however, if an owner is contemplating U.S. Green Building Council LEED certification or if ASHRAE 90.1-2010 compliance is required, commissioning is mandatory.
- Know the codes and standards that define lighting commissioning requirements.
- Understand how lighting controls play a role.
- Determine the commissioning authority’s role.
Many building owners are just now realizing the importance of commissioning lighting systems. Addressing lighting deficiencies via commissioning has been documented to generate a 1.1- to 4.2-year payback (The Lawrence Berkeley National Laboratory, 2009). Studies show that more than 30% of new buildings have lighting deficiencies that could be rectified through proper commissioning (Lighting Controls Association, 2012).
Recently, a large company with more than 2,500 retail stores that included exterior lighting did not have a commissioning process or requirement. A field survey of the stores indicated that most had exterior lighting fixtures with lamps that were lit 24 hours a day, 365 days a year.
Many of the stores had exterior lighting controls that consisted of an astronomical time clock. However, many of these clocks were never programmed correctly, which meant the exterior lighting did not turn on at dusk. The controls were set to override, leaving the exterior lighting on all the time.
According to conservative estimates, 50% of these stores had lighting that did not turn off. Calculations estimated that the company could save more than $1.5 million annually if the exterior lighting for these 50 stores would turn on at dusk and off at dawn.
Commissioning lighting systems helps reduce energy consumption and operating costs. Other benefits include client/user satisfaction and acceptance of lighting control systems. Also, commissioning can result in increased marketability and value of a building.
Lighting controls have grown in complexity with energy codes such as ASHRAE Standard 90.1: Energy Standard for Buildings Except Low-Rise Residential Buildings and U.S. Green Building Council’s LEED programs. Daylighting controls, occupancy/vacancy sensors with adaptive technology, astronomical timers, time-of-day shutoff, and multiple step-dimming lighting levels are some of the common lighting controls incorporated into building design and operation.
How does an engineer or commissioning agent commission these complex lighting controls? Fortunately, there are guidelines and processes: ASHRAE Guideline 0-2005: The Commissioning Process and ASHRAE Guideline 0-2013: The Commissioning Process; ASHRAE Standard 202-2013: Commissioning Process for Buildings and Systems; the ACG (AABC Commissioning Group) Commissioning Guideline; and IES DG-29-11: The Commissioning Process Applied to Lighting and Control Systems.
The IES Lighting Handbook, 9th Edition, defines commissioning of lighting systems as “a systematic process that ensures that all elements of the lighting control system perform interactively and continuously according to documented design intent and the needs of the building owner.”
Energy codes and LEED certification have made commissioning of lighting controls a requirement. ANSI/ASHRAE/IES Standard 90.1 requires functional testing of lighting controls and systems.
LEED Version 4 (the latest version of LEED) uses ASHRAE 90.1-2010 as the baseline energy code. Not only does Standard 90.1 require functional testing of lighting controls and systems, LEED Version 4 certification requires that lighting systems be commissioned. Functional testing is a core component of commissioning.
This discussion focuses on LEED Version 4 BD+C (Building Design and Construction). LEED BD+C applies to new construction and major renovation, core and shell, schools, retail, data centers, warehouses and distribution centers, hospitality, and health care.
LEED Fundamental Commissioning and Verification is an Energy and Atmosphere prerequisite; a project cannot be LEED Certified without meeting it. LEED defines the intent of Fundamental Commissioning and Verification to support the design, construction, and eventual operation of a project that meets the owner’s project requirements for energy, water, indoor environmental quality, and durability.
LEED requires that ASHRAE Guideline 0-2005 be used as the commissioning process. The LEED BD+C Reference Guide does not state the methodology to commission lighting systems. Fortunately, IES DG-29-11 is to be used as a supplement to ASHRAE Guideline 0-2005.
IES DG-29-11 includes requirements for lighting and control systems to fully support the commissioning process documentation, verification, and acceptance activities during each phase of the commissioning process, including a systems manual and training for operations and maintenance personnel and occupants.
LEED Enhanced Commissioning is an Energy and Atmosphere Credit. There are 2 to 6 points available for this credit, and they can be obtained via two options. The first option involves implementing Enhanced Systems Commissioning (3 to 4 points) by either going with Enhanced Commissioning (3 points) or Enhanced and Monitored-Based Commissioning (4 points). The second option requires envelope commissioning of the building.