Lighting The Kitchen by Michael De Luca, CKD, ASID, NCIDQ

Lighting The Kitchen
By Michael De Luca, CKD, ASID, NCIDQ, General Contractor
Published 12-'97: Journal of Light Construction

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Building Your Client Base
Lets face it, kitchens are expensive and most people only do one kitchen renovation in a lifetime. It is up to us to make sure that the most is made of their investment which serves the customer and is good for the builder. Referrals come from satisfied customers.

Often the work performed in a kitchen, meal prep and clean up, is done after the sun has set. This is also the time when most people entertain friends, family or neighbors; all potential customers. Effective lighting provides adequate illumination to the general space, to specific work or task areas (the counters), and renders the colors of the components in the room accurately.

General and Task Lighting
There are two types of lighting necessary to any kitchen; general and task. General lighting simply provides enough illumination to walk about the room. Task lighting provides a much brighter illumination to the working surfaces. Both should afford even coverage. In other words, no dark or bright spots between lamps. Even lighting comes from proper spacing.

Spacing
Spacing is measured from the center of one fixture to another or from the center of the fixture to the wall. Consider that the light produced by the lamp occurs in the shape of a cone which rests at counter height (36");the workplane. The relationship of these cones determines good spacing. If you think about it, there will always be one cone from the wall to the first fixture. From fixture to fixture there will be two cones.

Across this example 120" room then, there are four cones. Dividing the number of cones (4) into the 120" width will give us the width of each cone (30") which becomes the dimension from the wall to the first fixture. The spacing between fixtures (two cones) will be 60". It doesn't matter how many fixtures are used, the cone method will always yield even spacing. If the cones overlap too much, there will be a bright spot, if they don't meet, there will be a dark area.

Shown at right is a lamp with a 55 degree beam angle. The lamps intersect 6" above the counter, to ensure good coverage, and have been shifted to the right so that the edge of the cone does not create scallops on the face of the wall cabinets. The undercabinet lighting then furnishes the counter with the brighter task lighting.

FootCandles & CandlePower
The "brightness" on the workplane for both general and task is measured in footcandles. In the kitchen, general lighting needs to be about 40 footcandles and task, 100. These are good rules of thumb although there are other factors beyond the scope of this article which impact the footcandle level.

If a lamp is placed five feet above the workplane, it will need to be rated at 1000 candlepower to provide 40 footcandles and 2500 candlepower to provide 100 footcandles. When the lamp is raised the candlepower will need to be increased, and when lowered the candlepower decreased.

There are books, charts and software which offer more detail is this area. Look for information on the Inverse Square Law.

Counter Lighting
Good task lighting provides adequate, even illumination to the counter surface and to the backsplash. The backsplash is a large part of the kitchen aesthetics. Proper spacing, coverage, and color are the criterion for proper counter lighting.

I like fixtures which space the lamps at or around 2" on center. Using strip lighting of this sort allows complete coverage across the bottom of the wall cabinets, thus distributing the light evenly not only on the counter, but the backsplash as well. Look for fixtures which use xenon gas filled festoon lamps; they look like "fat" automotive fuses. They install quickly in lengths up to 12 feet which can be trimmed every 2". The resulting even field of light reduces visual "chop" and creates the illusion of a larger room; something every client will enjoy.

Under-cabinet fluorescent fixtures using T5 or "pencil" lamps are available only in limited sizes which leave gaps between fixtures. These gaps become dark areas on the counter and backsplash. They also yield very poor color.

Use cans or pendants over islands or above sinks at the windows where there are no wall cabinets.

Recessed Trim
Recessed cans have been outfitted with black step baffle trims for years. This trim absorbs 50% of the light generated by the lamp (talk about energy inefficiency). The black trim also contrasts greatly with the usual white ceiling which draws the eye and creates a decidedly Swiss cheese effect.

Consider using white trims, or even better, the mirrored Alzak or clear specular reflectors. White trims still absorb about 30% of the light while the Alzak allows virtually all the light to exit the can. The mirrored surface reflects the color of the ceiling causing it to "disappear" better than the white trim.

Color
Lamps must reproduce the colors in the room properly. Without a lengthy discussion as to how it all works, just remember the following:

For task, accent, and art lighting use halogen lamps. PAR halogen or MR16 lamps (all of which are halogen) do an excellent job. For art, MR16 lamps are preferred since they throw their heat back and away from the art.

For general lighting, use PAR halogen lamps or compact fluorescent. Compact fluorescent lamps should be about 3500 kelvin (they range from 2700 - 6500 kelvin) to approximate the color of halogen lighting which may be used elsewhere in the room. Doing this ensures that all like colored objects will look the same.

These pictures are intended to show the quality of colors illuminated by various lamps.
Represented within the limits of modern monitors.

GE SPX
Philips Ultralume
Sylvania/Osram Designer 800 GE SP
Philips SPEC
Sylvania/Osram Designer GE Cool White
Philips Cool White
Sylvania/Osram Cool White

3000 Kelvin 3500 Kelvin 4100 Kelvin

CRI 82 CRI 73 CRI 62

These pictures are intended to show the quality of colors illuminated by various lamps.
Represented within the limits of modern monitors.

GE SPX Philips Ultralume Sylvania/Osram Designer 800	GE SP Philips SPEC Sylvania/Osram Designer	GE Cool White Philips Cool White Sylvania/Osram Cool White
3000 Kelvin	3500 Kelvin	4100 Kelvin
CRI 82	CRI 73	CRI 62

When using other types of fluorescent, remember to use lamps that are over 80 CRI (color rendition index) AND between 3000 - 3500 kelvin. All compact fluorescent lamps are over 80 CRI. CRI rates the lamps ability to reproduce an objects color accurately. Lamps falling outside these recommendations, in my opinion, destroy color!

Codes
Reflector (R) lamps have been discontinued by EPACT, a federal energy law. It is time to make the move to PAR Halogen, or even better, the compact fluorescent lamps. Both provide better efficiency and color, and the compact fluorescent does not generate unwanted heat.

In California, as in many other states, IC cans are required for all recessed lighting and fluorescent must be used for general lighting in kitchens and baths. To meet the code, use recessed compact fluorescent with Alzak trims. The cans are about 7 5/8" in diameter, and are designed with the ballast near the junction box. The lamps are pin mounted and recess completely into the can (something the retrofit compact fluorescent lamps have not done). These cans are more expensive, but far fewer fixtures are required which makes them less expensive than a 7" can, black step baffle, 75 watt R40 lamp combination when comparing equal amounts of light output.

Michael De Luca is the author of LightCalc; a software program written for architects, designers, and contractors as an aid in providing proper lighting design quickly. Available from Enviro-Systems , (619) 596-0047.

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