Michael Lane LC

archived articles

Restaurant Lighting
April 1997

Is quality efficient lighting in restaurants a oxymoron?

Yes, we can use energy efficient luminaires using T8 fluorescent, and compact fluorescent in fast food and buffet style restaurants, and retain quality. But what about the more formal, higher end atmospheric restaurants? These restaurants depend on that atmosphere, along with their food and service quality, for their business. Not to say that fast food and buffet style restaurants don't have atmosphere; it's just a different type of atmosphere. In the more formal restaurants, energy efficiency may be difficult to achieve by technology alone. Energy efficient design must be used.

Typically the lighting in a fast food and buffet style restaurant is general in nature. Maybe there are pendant luminaires over some of the booths, but the primary lighting is often from an incandescent downlights that evenly lights the dining area. Is there any reason not to use fluorescent lighting in this type of restaurant?

In existing restaurants, with incandescent lighting, the downlights could be retrofitted with compact fluorescent. Or better yet, replace the existing incandescent luminaires with new luminaires that use the "pin base" compact fluorescent lamp. Screw-in compact fluorescent lamps may make economic sense from a first cost standpoint, but when the lamp fails what guarantee is there that they will not be replaced by an incandescent lamp? None. In fact it is extremely likely that the compact fluorescent lamp will be replaced by an incandescent lamp. Unfortunately many end users can be very unsophisticated when it comes to lighting: If the luminaire has a medium base, screw in the least expensive lamp that you can find. I'm sure you have seen the A-lamp in the R-lamp luminaire many times (now there's an efficient combination). That's the big advantage of the "pin-base" compact fluorescent lamp -- the reflector is designed around a specific lamp and only that lamp works in the luminaire.

When retrofitting incandescent to compact fluorescent, refer to Table 1 for appropriate lamp wattages. Let's assume that the existing incandescent downlights use a 100 watt incandescent lamp. By converting to a 26 watt compact fluorescent luminaire, the lumens delivered will be equal, the wattage will be cut more than 2/3rds, and the life will be 13 times greater. From an economic comparison the incandescent will use $48.00 per year compared to only $14.40 for the compact fluorescent. Assuming $0.08/Kwh and 6,000 operating hours per year. Additionally, the incandescent lamp will need to be relamped eight times in the first year while the first compact fluorescent lamp will still be operating. From an energy an maintenance standpoint, yes it makes sense to use compact fluorescent lampsinstead of incandescent.

The pendant incandescent luminaires may need to be retrofitted with screw-in compact fluorescent lamps if the specific style of the luminaire is important to the decor. Sense the lamp is close to the patron, use a CFL lamp with a shade to diffuse and soften the lamp image. Remember that "most" screw-in compact fluorescent lamps are not dimmable and you will need to remove all dimmers that control these luminaires.

The question of color will always be a consideration. The 2700K lamp is very close in color to incandescent, and can be mistaken for incandescent if the lamp is hidden behind a diffusing shade. The color rendering of compact fluorescent is very close to incandescent, but I have heard the stories that compact fluorescent will make food look green, especially eggs. I decided to try it out, and my honest opinion is that compact fluorescent lamps --all fluorescent lamps for that matter -- give food a slightly green cast if you look hard enough. (What's wrong, "Do you not like green eggs and ham?")

Full size fluorescent lamps (T8's) can easily be used for general lighting in fast food and buffet style restaurants. They can be placed in coves to uplight the ceiling, or in recessed 2-by-4s or 2-by-2s with small-cell parabolic louvers or prismatic lenses depending on the atmosphere desired. Let's just agree never to use cool white lamps and everyone will be happy.

In higher end restaurants it may be difficult to use fluorescent for the majority of the lighting. Fluorescent lighting may be limited to providing a low ambient light level from a cove, lighting a fake skylight, or edgelighting sandblasted glass. Full size 4-foot fluorescent lamps can be easily and cost-effectively dimmed to soften their intensity, but compact fluorescent lamps are expensive to dim. The days of affordable compact fluorescent dimming have not arrived, yet. Halogen incandescent lamps on the other hand are easily and inexpensively dimmed.

Maybe in higher end restaurants energy efficiency is relegated to the kitchen, restrooms, and support areas. But aren't halogen incandescent lamps energy efficient? Yes they are, compared to standard incandescent lamps. However, I consider halogen incandescent lamps, not the standard incandescent lamps, as the base line for energy efficiency. With incandescent (halogen) lamps the energy efficiency is in the lighting design, not the lamp. It is for the designer to decide: Do I want the light to focus just on the flower in the center of the table by using a narrow spot? Do I want to light to fill the entire table with light by using a narrow flood or flood? How many other objects, plants, signage, photographs, etc., do I light? Do I need to dim the lights? These questions must be answered by you and your client, and will be the biggest influence on how energy efficient the project is.