Technological fads come and go, but one main objective will always remain constant when specifying a fixture: achieving light quality. The success of a well-lit space is often the result of layers of light, and does not wholly rely on a single fixture type. Each lighting selection adds a new dimension to the overall design and feel of a space, and must be chosen with care. When it comes to commercial spaces, direct/indirect luminaires are a main stay, due their versatile illumination capabilities. Here are some tips for selecting and specifying these fixtures.
The Basics
Direct/Indirect fixtures can be fitted with either just an up- or downlight distribution, or a combination of both; the uplight (indirect) component can provide a softer ambient glow, while the downward (direct) light provides a general level illumination for the workplane. Used independently, indirect lighting can leave “the space [feeling] dull, like being outside with a gray sky, because nothing is punched up or highlighted,” says Michael Hennes, an associate principal at Cline Bettridge Bernstein Lighting Design in New York City. He also warns, “be careful that the direct component has good shielding so that it doesn’t become glary.”
Reflectance
Multiple factors come into play when selecting a direct/indirect luminaire. To the lighting novice, ensuring that the fixture aesthetically coordinates with the interior design of a space may seem like the most important consideration. Elements such as shape, size, and mounting options are significant, but it is vital to attend to the technical criteria of lighting as well, such as the reflectance level of a ceiling material, says Maureen Moran, principal at Washington, D.C.–based MCLA Architectural Lighting Design. “If [the ceiling] is white, then [there is] more contribution onto the work surface below,” she says. “Dark, wood ceilings normally have a finish that will reflect the lens of the uplight, for a less desirable result.” The height of the ceiling should also be accounted for, since for example, a narrow space between the fixture and ceiling could produce an unwanted beam reflection.
Light Distribution
Determining a luminaire’s light distribution is also a key consideration. Since direct/indirect fixtures can emit light both up and down at specific percentages, designers must find the right balance for appropriate light distribution. “The indirect portion of the light distribution should be very wide in order to uplight the ceiling evenly,” says Melanie Taylor, vice president of lighting design in New York–based firm WSP. “The direct portion of the light distribution can be narrower in order to light the workplane below.”
Price and Delivery
As every project has a budget and a timeline, price point and delivery lead-times are additional factors to consider. But this is where it gets tricky: Because lighting manufacturers do not publish a price list for their products, and the lighting design budget is generally a percentage of the overall project cost (not part of a separate budget) it is often difficult to calculate what the final expense will be.
When it comes to a project schedule, designers can usually expect a standard 8- to 12-week lead-time, says Taylor. When confronted with a tight deadline, availability and lead-time will likely play a larger role in making fixture selections. Most manufacturers have a quick-ship option to expedite the fixture assembly and shipping process, which can significantly reduce the timeline to as little as 5 days with, and 10 days without a surcharge. However, it is recommended that designers check directly with the specific manufacturer.
Operations
What happens once the fixtures are installed? Ease of maintenance is a vital post-occupancy issue to consider ahead of time. “Although LEDs are very long-life, drivers can fail and LEDs can have a catastrophic failure,” Hennes says. “So it is important that the fixture can be serviced.” The compatibility of luminaire components has always been an issue, but is now highlighted because of LED technology. The different lifespans and warranty issues related to the driver and the light source pose new challenges in terms of compatibility of fixture components, and must be kept in mind.
Additionally, manufacturers do not always include details on maintenance for their products, Hennes adds, so it is often up to the designer to dig deeper for their client. Ultimately, the long-term maintenance of the luminaire will fall to a facility manager, who is tasked with maintaining its operation, but it’s up to the lighting designer to specify a product that can maintain technical performance while staying true to the design integrity of the lighting scheme.
Discover some recent direct/indirect fixtures below:
