Compact fluorescent down lights for a kitchen are not my first choice!

I'm considering 5" or 6" CFL recessed lighting for general lighting in a kitchen (8 foot ceiling). California title 24 makes this an attractive choice, but many contractors have negative comments on the color and look of fluorescent. Manufacturers state bulbs (such as 26W TTT) are available in 2700K or 3000K to approximate incandescent. Do you have any experience to comment on the similarity of the CFL downlight w/ LV MR16 or PAR30? Also, is something like Elco prismatic lens recommended to break up the lamp, or are normal baffle trims OK w/ CFL? Finally, is 26W acceptable for general lighting if fixtures placed 5 or 6 ft spacing? Thanks for a good site!

I can't say that fluorescent, particularly compact fluorescent, would be my recommendation for kitchen lighting - or really any residential lighting for that matter. Fluorescent is a great source for a lot of reasons - great light output for relatively little wattage, even distribution of light, very long lamp life - up to 20,000 hours. It''s an excellent choice in large commercial applications for all those reasons, but I very rarely use it in homes. There are several reasons for this:

Glare

Compact Fluorescent is a very efficient lighting source (that's why California likes it). But what that ultimately means is that you're getting a lot of light output out of a very small area (you've essentially taken a 4'' fluorescent tube and compacted all that light down into a 6" bulb). That concentrated amount of light equates to glare when you look at the fixtures, particularly with your 8' ceilings, where the lamp will be well within your viewing angle. A prismatic lens would probably solve this because it would help diffuse the light, but personally I don't like that look - seems very office-y to me, and fairly outdated looking. A baffle trim potentially presents a different trouble, because a cfl emits light in every direction and thus depends on the fixture reflector to push its light out. A PAR lamp has its own reflector built in, so the fixture is much less of an issue in terms of light output Once you put a baffle on a cfl fixture you're significantly reducing the light you can get out of it and negating a lot of the efficiency that made the fixture so attractive to begin with.

Color

You are correct about the color temperatures (2700K and 3000K) that come close to approximating incandescent. Those are at the warmer-looking end of the spectrum and will have more of a yellow cast to them vs the blue/greenish tint that fluorescents are known for. But that's only half the story. All light sources also have a number for their Color Rendering Index (CRI), with 100 being the ultimate, equal to that of the noonday sun. The CRI indicates how well the light source can adequately render the FULL spectrum of colors - cool colors like blues and greens, warm colors like reds and yellows, and everything in between. This is where the fluorescent will fall flat. Halogen is generally the best man-made source for rendering colors their truest, with CRIs in the 90s (which is why it is the first choice for art lighting, etc), Incandescent is also good, with a slight preference for the warmer tones, and next is fluorescent. If you do decide to use fluorescent, look for one with the highest CRI you can find--one at least in the 80s, not the 70s. A low CRI will be unflattering to people, make food unappetizing, and will not enhance your decor including countertops, cabinets, etc.

Control

As a designer, I recommend using dimmers in nearly every room of the house There's just no reason not to - they are a nominal expenditure to give you control for different needs (nighttime trip to the bathroom, dinner party, etc), different times of day, they save energy, and, on incandescent loads, can increase lamp life exponentially. Kitchens are an especially advantageous room to have a dimmer in since, these days we''re often entertaining guest in the kitchen, perhaps eating a meal, etc. Full bright fluorescents all day, every day hardly set the mood. That said, fluorescent loads cannot be dimmed without a special dimming ballast (all fluorescents require a ballast to operate), which is a costly adder for each fixture. Maybe you say, well, if I install it and I feel like there's too much light I'll just replace the lamps with a lower wattage. With fluorescent you don't have that option as you would with incandescent (again, unless you buy a costly ballast), since the ballasts correspond to the wattage they are controlling.

Since my work is concentrated in Texas, it is hard for me to comment directly on the California code, but here are some things to keep in mind. Lighting makes up for only about 15% of the average household's energy consumption. Air conditioning, heating, appliances, and electronics consume much more, and all of those areas are worth looking at for saving energy (in addition to good home insulation, windows and doors, etc.). If you use halogen/incandescent PAR lamps, look for IR lamps (a relatively new technology in the last several years which allows the lamps to reharness it''s own energy, giving you equal light with fewer watts. You can, for example, get a 37w MR16 that has equal light output to a 50w.) And, in your layout, instead of trying to light up the whole room brightly, spend your wattage where it makes the most difference--on your task areas and countertops.

And last, on spacing, 5-6'' sounds plenty close - too close if you have cfl downlights without a dimmer in an 8' ceiling. If you go with incandescent/halogen that's probably fine, since you will have a dimmer. All that said, it's hard to say exactly what spacing will work best without seeing your kitchen plan - as I said, I'd recommend looking at where you really need the light and placing fixtures there vs. doing a blanket grid across the whole room.

Good luck on your endeavors!

Labels: Color Chart, Control, Glare, Kitchen Lighting

posted by xinger @ 2:20 PM