Cree Launches Dissipation-Defying 75W-Equivalent LED Bulb
17-03-2015
ExtremeTech reported that Cree, the LED company best known for their $10 LED bulb, has had a busy year. After releasing the Cree LED bulb in 40W- and 60W-equivalent models, the company went on to ship a high colour accuracy model, the Cree TW, and a BR30 directional bulb. Today, well under a year since the release of its first consumer LED bulb, Cree has announced a 75W-equivalent, 1100 lumen model, priced at $24.
Cree LED bulb
Cree LED bulb
The 75W-equivalent Cree LED bulb produces 1100 lumens at 13.5W, which means it operates at an excellent 84.5 lumens-per-watt. The bulb is rated for 25,000 hours and runs at 2700K. As with Cree's other bulbs, it's backed by the company's 10-year warranty.
The release of a 75W-equivalent LED bulb is especially important for Cree at this point for a number of reasons. First of all, there is very little competition at this brightness level. LED bulb manufacturers have focused largely on 40W and 60W replacement models because these are cheap and the heat the LEDs produce is easier to dissipate than at higher brightness levels. Secondly, the new Cree bulb was able to use the same design as the 60W model, which is both efficient for the company and proof that the "filament tower" design Cree pioneered can be successfully scaled.
On the design side, the Cree 13.5W is nearly identical to the Cree TW, which is to say that it looks like a slightly larger version of the standard 60W model. Basically, all the main components are same, but the metal collar heatsink was made slightly large to dissipate the extra 4W. Interestingly, the filament tower design was not changed so it still uses two rings of ten Cree LEDs to emit light. What Cree did to increase the lumen count was to simply overdrive the high-power LEDs — this uses more power and puts out more heat, but the added cooling prevents it from affecting the lifespan of the LEDs (according to Cree).
Even with the increased size of the heatsink, Cree still uses a standard A19 bulb size. Other manufacturers have had to inflate the size of the 75W- and 100W-equivalent (1600 lumen) bulbs in order to deal with the extra heat. These generally use the next size up — A21 — which means the bulbs can stick out of fixtures and look ungainly. The Cree 13.5W still looks more like an incandescent bulb than any LED lamp on the market.
While 75W is an ideal proving ground for Cree's technology, these bulbs make up for just a small percentage of overall sales. 40W and 60W replacement bulbs are estimated to account for over 80% of the A-shape (normal bulb shape) market, with 75W-equivalents being under 10%. The other side of this is that these high-lumen bulbs are often placed in areas like kitchens and hallways that get used for more hours per day than other models. This means they can have a great impact on lowering energy costs
It will be interesting to see if Cree is able to scale its design up to the 100W level. This point has been a huge challenge for LED lamp manufacturers — for most, it's just been too difficult to balance the size, price, and heat restrictions that crop up. The 13.5W model, impressively, uses the same LEDs and filament tower as the 60W version, but it's not clear if that will be work at the next brightness level. Cree says the design should be able to scale, and the company has been extremely happy with how it's gone so far.
The 75W-equivalent Cree LED bulb will be in Home Depot stores in the US by the end of December and will be available online this week, priced at $24.
In the UK market, leading LED lighting distributor, Novel Energy Lighting, sells 75W equivalent and 100W equivalent LED bulbs manufactured by Philips and Megaman. The Philips MasterLED GLS 13W=75W puts out 1055lm, and the MasterLED GLS 20W=100W puts out 1521lm. These are both dimmable GLS bulbs and deliver a very pleasing high quality light output.. Only top quality LED lighting is sold, proven to last longer and produce more brightness with lower energy costs, unlike traditional lighting.