Lighting design should be part of the initial facility design phase to ensure effective illumination and energy savings.The intended use for a building and the owner’s design goals not only affect the layout, finishes, and furnishings, but have a significant impact on lighting needs and energy costs. Unfortunately, lighting often is not discussed in the early design stages for new and major renovation projects. If lighting is a part of the early discussions, it is much more likely that the best possible luminaires will be chosen to fit the style of the building and its intended use.
Discussing lighting early will also help ensure the building’s design can accommodate the desired luminaires and controls to achieve the lowest energy and maintenance cost without sacrificing lighting quality. Before specifying lighting, answer the following questions.
Who is the end user?
Is the building owned by a company for its own use or is the space being leased to multiple tenants? For businesses, branding by way of unique building design and layout plays a part in establishing that brand. In addition, exterior and interior lighting are equally important for the safety and well being of workers, customers, and clients. If a building is to be occupied by a single company, it is easier to minimize the number of luminaire types. For leased spaces, tenants often want the space constructed to meet their requirements, and this includes lighting. Lease agreements vary, but tenants often are required to pay utilities on the leased space, so work with them to install the most energy-efficient lighting possible.
What is the desired style or look?
Aesthetically pleasing lighting can be modern, contemporary or traditional, and there is a variety of luminaires from which to choose. For an unobtrusive modern look, recessed flat-panel, recessed indirect, or architectural recessed 1×4, 2×2, or 2×4 luminaires can provide a very clean look and uniformly lit spaces. For a more contemporary look, single pendant-mount luminaires can be geometrical, adding an artistic look to the space. There are also more traditional long linear runs of indirect/direct pendant-mount luminaires with an up-light and down-light component providing extremely low-glare lighting. In addition, these luminaires light the ceiling, brightening the look of the space.
You do not need to sacrifice on the aesthetics of a luminaire just to save energy. State-of-the-art high-efficiency, long-life fluorescent lamp and ballast systems are available in many styles, providing energy savings as high as 40%, compared with standard T8 fluorescent units. Luminaires using LED systems that offer energy savings as high as 50% when compared to conventional fluorescent systems are available.
How will spaces be used?
How a space is to be used determines required lighting levels. In the past, however, many interiors have been over lit. Fortunately, the Illuminating Engineering Society of North America (IESNA), New York, has established recommended lighting levels for specific tasks, and following these guidelines will reduce over-illumination and wasted energy.
The type of space will also dictate the need for additional lighting controls, and this may influence your luminaire choice. Many LED luminaires come with integrated controls for installation ease. Also, layers of light, especially for hospitality and classroom lighting, provide the flexible lighting typically desired. For office environments, the use of task lighting allows overhead lighting levels to be scaled back, reducing energy usage.
What are the latest energy code requirements?
ASHRAE 90.1 and California Title 24 have maximum power-density requirements (W/sq. ft.) and mandatory control provisions for interior and exterior applications. The latest versions of each have additional mandatory control requirements. Alterations affecting more than 50% of the lighting load must conform to the codes.
ASHRAE 90.1-2010 requires space control for enclosed areas with at least one control step between 30% and 70% of full power. Exceptions include corridors, public lobbies, restrooms, stairwells, storage rooms, and electrical/mechanical areas. Various auto-off requirements also are established, particularly for parking garages.
California Title 24 2013 has added more multi-level control requirements, specified by space type for areas greater than 100 sq. ft. Auto-off requirements are also established for interior and exterior spaces and parking garages. There also are specific requirements for daylighted zones and use of occupancy sensing or auto scheduling. Demand response is now required for all non-residential buildings of more than 10,000 sq. ft.
When does daylighting make sense?
There is trend in commercial buildings to use more natural light and provide occupants with outdoor views for health and well-being benefits, as well as to save energy. However, to make daylighting effective, the building design and window selection are extremely important. North/south-facing windows and windows with the proper glazing to minimize glare need to be incorporated into the design. In new-building construction, light shelves and skylights improve daylight use. A window-shading system can effectively control the amount of sun that enters a space. Light sensors and 0- to-10-V dimming is the best way to reduce the luminaire light level in response to available daylight.
Which lighting technology?
The cost to install LED lighting instead of conventional fluorescent and high-intensity-discharge technology has decreased immensely in the past several years. LED luminaire performance, controllability, and color quality is equivalent to many fluorescent systems, so for new construction LEDs may be the best choice. For retrofit projects, high-efficiency, long-life fluorescents may be the least expensive option, but do not rule out LED retrofit solutions that use the existing luminaire housing. Utility rebates are available for DLC-qualified (DesignLights Consortium, Lexington, MA) LED luminaires and for high-efficiency and supersaver fluorescent systems, reducing the cost to install the most efficient lighting.
Lighting can help shape a business and its outcomes in very subtle ways. When done correctly, it can dazzle people, provide comfort, and improve productivity. Quality lighting does not need to break the budget, and it can be very energy efficient. In evaluating lighting options, look at the total cost of ownership. Hire a lighting designer to make sure the best lighting system is designed for the facility.
Cheryl Ford is a marketing manager for OSRAM Sylvania, Danvers, MA. She has
more than 30 years of lighting experience; has held various positions in engineering, marketing, and sales; and is a NCQLP lighting certified professional. Watch for regular lighting columns from Cheryl at cbpmagazine.com/blog.