Home Depot (NYSE: HD) is going after more than hall lamps with its latest LED light bulb announcement.

The DIY giant has started to sell a line of LED downlights -- those interior lights that look like small floodlights -- for homes. The bulb was designed and will be produced by Cree (Nasdaq: CREE), but sold under Home Depot's EcoSmart brand. Home Depot will also sell Philips-made LED bulbs and already announced it was selling Lighting Science LED bulbs under the EcoSmart brand back in May.

The Cree/EcoSmart bulbs cost $49.95, last for 35,000 hours and emit about the same amount of light as a 65-watt incandescent downlight. It will screw into standard ceiling fixtures. Cree says the bulb over its lifetime -- which will be 32 years if you use it about three hours a day -- will save consumers $300. The bulbs are available on the Home Depot site now and will be in stores in the fall.

"20 million downlights are sold a year. They are increasingly used in new construction and retrofits," said Ty Mitchell, vice president and general manager of LED lighting at Cree.

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Osram Sylvania back in May promised an LED bulb by August, so expect something from that company soon, although it may not be in collaboration with Home Depot.

The bulb in part grows out of a line of LED bulbs that Cree already sells into the commercial market. Cree combines white and red LEDs inside the bulb so the bulb emits a warm, bright light similar to the light that comes out of familiar, but highly inefficient, incandescent bulbs. You won't see red spots interspersed with white-bluish light because of the white/red mix, or even a sparkling rose. It will look like regular light.

The EcoSmart bulb costs less than Cree's earlier commercial versions of this type of bulb that are already on the market. Cree will also sell a version of the EcoSmart bulb to commercial customers.

Most bulb makers tinker with the phosphor to boost the warmth and take some of the harsh glare out of white light LEDs. The white/red approach, however, results in a more energy-efficient bulb that can put out more light while using less power, according to Cree. Cree also has intellectual property on combining whites and red in this way. (Cree's intellectual property portfolio is something nearly all LED makers have to contend with, either by trying to work around it, or paying Cree royalties under a licensing agreement.)

Philips, Osram and others earlier this year unfurled plans for LED bulbs to replace familiar "A" type bulbs. Earlier this month, Home Depot itself began to tout a 40-watt equivalent standard bulb developed by Lighting Science. General Electric (NYSE: GE) has an LED bulb coming that is also based around LEDs from Cree.

Technically speaking, Cree's downlight will emit 575 lumens and consume 10.5 watts. An equivalent incandescent would consume 65 watts and emit 635 lumens. While the LED bulb emits fewer lumens, fewer lumens are wasted due to the optical characteristics of bulb.

"Brightness is not going to be a problem," he said. "It appears brighter to most folks."

An equivalent compact fluorescent downlight might only consume 15 watts, or close to the level of the LED downlight. But CFL downlights contain mercury, don't last as long, and, perhaps most important of all, don't dim, or at least don't dim in most circumstances. Dimmers and downlights are often used in tandem in homes.

A note on lumens. Typically 60-watt equivalent A bulbs emit 800 lumens. The 60-watt equivalent A bulbs announced by Osram and Philips earlier this year will emit, respectively, 810 and 806 lumens.

Downlights emit fewer lumens. The 65-watt equivalent bulb shown here will emit 575 lumens. The parabolic shape and interior reflective surfaces, however, make downlights more efficient, so you get more illumination for less wattage.

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