Lighting Control Narrative Helps with Purchasing, Installation of Systems
As many facility managers have learned, lighting systems are becoming increasingly automated and networked, as well as complex and sophisticated. In part, this is a result of building owners' heightened focus on energy savings: More sophisticated lighting systems can make greater use of daylight and reduce energy use, while still providing the light needed for the building's occupants to do their jobs.
As lighting systems become more complicated, the lighting control narrative (LCN) has become increasingly important. This narrative is a tool that allows all participants in the design and construction of a space to understand the owner's intent for the lighting system, and then determine whether it is being achieved, says Craig DiLouie, education director with the Lighting Controls Association. "The controls narrative provides a simple road map for all project participants to see the intent of this one subsystem. It's a great reference," he says.
A thorough, accurate LCN increases the likelihood that the design satisfies the owners' project requirement, DiLouie says. The owners' project requirement documents the requirements of the building owner, such as any environmental and energy efficiency goals, as well as expectations for the building systems.
Developing an LCN can benefit all parties involved. The contractors and manufacturers have clear directions for the bidding, installation and startup of the project, which lowers the chance that they'll incur expensive errors. The commissioning agent knows how best to test the system. An LCN also helps ensure that the owner receives a quality project. And occupants should enjoy a lighting system that functions well within the building.
LCNs are "even useful to the original specifier, since many projects have long construction periods, or there is a delay between the issuance of the bid document and the receipt of shop drawings," says Hayden McKay, principal with Horton Lees Brogden Lighting Design, Inc. She describes her work commissioning a project that had been designed five years earlier. "The narrative often reminds me of the reasoning behind some strategy that is not immediately obvious. Often that reasoning is a special consideration that was added by the owner."
In retro-commissioning projects, in which an expert identifies low-cost operational and maintenance improvements that can be made within existing buildings, the lighting control narrative also is extremely valuable. "It is the only document that describes the intent (of the building owner) in a common language," McKay says. The LCN should allow even a layperson to determine whether the system is correctly operating. It also will explain why the system was designed the way it was.
Moreover, one of the requirements of ASHRAE 90.1-2010, Energy Standards for Buildings Except Low-Rise Residential Buildings, is "a complete narrative of how each lighting control system is intended to operate, including recommended settings." This document, along with the operations and maintenance manual and inspection schedule, among others, is to be turned over to the owner within 90 days of system acceptance.