Electric-Light
Senior Member
CREE, a well respected manufacturer of high power LEDs has entered lighting fixture market and they're trying to gain market over fluorescent in commercial lighting. A few years ago, they only made LED chips. Now they make complete LED luminaires in their own name.
CREE is trying to gain name recognition from those who embrace technology through participating in social network sites, such as Facebook, Twitter and posting YouTube videos.
They have generally poor attitude about existing dominant technologies. While its okay that they promote their product, I feel that they're misrepresenting existing technologies.
CREE troffers allow skipping of one group re-lamping. Maintained efficacy is not quite as good as fluorescent. Upfront cost is about 3x as much. Quality of light is comparable to best available T8.
Example 1: agenda against fluorescent lighting
http://www.youtube.com/watch?v=nbMyY59x8Cs
This video portrays fluorescent lighting as flickery, nasty cold colored, poor color rendering light. Something that is stereotypical to older cool white lamps using halophosphate phosphor blend and magnetic ballast operation that hasn't changed much in half a century.
T12 lamps are still available in energy saver version in common commercial lighting sizes. 4100K 62CRI, 34W 48", 60W 96" and 95W 96" HO. These are getting banned in July 2012 and newer fluorescent lamps are substantially better, so its hardly fair to compare against the old tech. Magnetic ballast fixtures are already banned.
New fluorescent lamps have much better color rendition at about 85. They are available in quite a few selection of color temperatures. Warmest being soft white/2700K and "coolest" being daylight 6500K and 3000K, 3500K, 4100K and 5000K to go in between the two extremes.
Lithonia ES8 fluorescent is around $110/ea online, and offers complete luminaire efficacy of 86 lumens per watt.
http://www.acuitybrandslighting.com/library/LL/documents/SpecSheets/2ES8P-2x4.pdf
CREE says the pricing is set by distributor and claims their troffers are priced competitively with "architectural grade" fluorescent fixtures. Some fancy 2x4 fixtures that look similar to the CREE troffer cost over $400. I really doubt the CREE troffer is $110.
KEY POINTS:
Fluorescent 2 lamp 2 x 4: $130 or so with lamps. More for decorative models.
Lamp life: 30,000 to 40,000 hours. Fluorescent lamps lose about 5% output over lifetime
86 lumens per watt. CRI: 85 Brand new, its not quite there with CREE LED's specs, but it does not degrade as much.
CREE LED troffer:
Probably $350+. 3500 or 4000K only, 90 CRI.
Efficacy is 90-110LPW on the day its commissioned, depending on the model chosen. The same models become 63-77LPW after 50,000 hours.
Also, 110LPW model is expected to cost more than 90LPW model.
fixture life, estimated by extrapolation to 70% output to 50,000 hours. Power consumption remains the same. LED fixtures are rated to lose about 30% over their lifetime, more if temperature is higher. THIS REALLY IS *A LOT* Even F40/CW from 40 years ago didn't lose that much, according to 1972 edition of IESNA Lighting Handbook
Both fluorescent and LED system suffer from LDD from dust accumulation in optics and require cleaning to maintain maximum fixture efficiency.
Example 2: LED is super cool running deception
http://www.youtube.com/watch?v=LyVU470TQBk
Incandescent lamps shed most of heat through infrared energy.
Many MR-16 lamps are available with reflector that lets the infrared leave through the back to reduce heat damage to the items being lit.
While CREE LED lights do not shed much energy as infrared, they're far from super efficient. They dump a substantial portion of input power through conduction through massive heatsinks.
PAYBACK CALCULATOR is messed up. Payback happens sooner when you over-estimate the maintenance cost of competing technology and assume that bank lends you money at zero interest.
http://crseries.creeledlighting.com/#payback
Conveniently omitted...
When each fixture is estimated to cost $220 more than a common high efficiency fluorescent fixture, how does this affect the overall project cost? Where does the cost difference come from and what about the opportunity cost or financing cost related to the higher upfront material cost?
Reality is not based on simple-payback-method calculation. If you have the money, there is opportunity cost to this spending. If you borrow it, the lender will charge interest.
The CREE Payback calculator assumes too short of lamp replacement interval for fluorescent benchmark and doesn't address the issue of financing cost associated with higher upfront cost.
over estimation of maintenance cost of fluorescent system used for comparison
Old magnetic ballast system usually lost two lamps for every failed lamp as they are series wired. This reduces group re-lamping interval. Lamp rated life is around 40,000 hours for high-end lamps when they're used in typical >12hrs/day commercial use. The relamp interval is around 70% of rated life for parallel wired instant start, so that is 28,000 hours. CREE payback calculator is downplaying this by about 45% using approximately 15,500 hrs for interval.
CREE is trying to gain name recognition from those who embrace technology through participating in social network sites, such as Facebook, Twitter and posting YouTube videos.
They have generally poor attitude about existing dominant technologies. While its okay that they promote their product, I feel that they're misrepresenting existing technologies.
CREE troffers allow skipping of one group re-lamping. Maintained efficacy is not quite as good as fluorescent. Upfront cost is about 3x as much. Quality of light is comparable to best available T8.
Example 1: agenda against fluorescent lighting
http://www.youtube.com/watch?v=nbMyY59x8Cs
This video portrays fluorescent lighting as flickery, nasty cold colored, poor color rendering light. Something that is stereotypical to older cool white lamps using halophosphate phosphor blend and magnetic ballast operation that hasn't changed much in half a century.
T12 lamps are still available in energy saver version in common commercial lighting sizes. 4100K 62CRI, 34W 48", 60W 96" and 95W 96" HO. These are getting banned in July 2012 and newer fluorescent lamps are substantially better, so its hardly fair to compare against the old tech. Magnetic ballast fixtures are already banned.
New fluorescent lamps have much better color rendition at about 85. They are available in quite a few selection of color temperatures. Warmest being soft white/2700K and "coolest" being daylight 6500K and 3000K, 3500K, 4100K and 5000K to go in between the two extremes.
Lithonia ES8 fluorescent is around $110/ea online, and offers complete luminaire efficacy of 86 lumens per watt.
http://www.acuitybrandslighting.com/library/LL/documents/SpecSheets/2ES8P-2x4.pdf
CREE says the pricing is set by distributor and claims their troffers are priced competitively with "architectural grade" fluorescent fixtures. Some fancy 2x4 fixtures that look similar to the CREE troffer cost over $400. I really doubt the CREE troffer is $110.
KEY POINTS:
Fluorescent 2 lamp 2 x 4: $130 or so with lamps. More for decorative models.
Lamp life: 30,000 to 40,000 hours. Fluorescent lamps lose about 5% output over lifetime
86 lumens per watt. CRI: 85 Brand new, its not quite there with CREE LED's specs, but it does not degrade as much.
CREE LED troffer:
Probably $350+. 3500 or 4000K only, 90 CRI.
Efficacy is 90-110LPW on the day its commissioned, depending on the model chosen. The same models become 63-77LPW after 50,000 hours.
Also, 110LPW model is expected to cost more than 90LPW model.
fixture life, estimated by extrapolation to 70% output to 50,000 hours. Power consumption remains the same. LED fixtures are rated to lose about 30% over their lifetime, more if temperature is higher. THIS REALLY IS *A LOT* Even F40/CW from 40 years ago didn't lose that much, according to 1972 edition of IESNA Lighting Handbook
Both fluorescent and LED system suffer from LDD from dust accumulation in optics and require cleaning to maintain maximum fixture efficiency.
Example 2: LED is super cool running deception
http://www.youtube.com/watch?v=LyVU470TQBk
Incandescent lamps shed most of heat through infrared energy.
Many MR-16 lamps are available with reflector that lets the infrared leave through the back to reduce heat damage to the items being lit.
While CREE LED lights do not shed much energy as infrared, they're far from super efficient. They dump a substantial portion of input power through conduction through massive heatsinks.
PAYBACK CALCULATOR is messed up. Payback happens sooner when you over-estimate the maintenance cost of competing technology and assume that bank lends you money at zero interest.
http://crseries.creeledlighting.com/#payback
Conveniently omitted...
When each fixture is estimated to cost $220 more than a common high efficiency fluorescent fixture, how does this affect the overall project cost? Where does the cost difference come from and what about the opportunity cost or financing cost related to the higher upfront material cost?
Reality is not based on simple-payback-method calculation. If you have the money, there is opportunity cost to this spending. If you borrow it, the lender will charge interest.
The CREE Payback calculator assumes too short of lamp replacement interval for fluorescent benchmark and doesn't address the issue of financing cost associated with higher upfront cost.
over estimation of maintenance cost of fluorescent system used for comparison
Old magnetic ballast system usually lost two lamps for every failed lamp as they are series wired. This reduces group re-lamping interval. Lamp rated life is around 40,000 hours for high-end lamps when they're used in typical >12hrs/day commercial use. The relamp interval is around 70% of rated life for parallel wired instant start, so that is 28,000 hours. CREE payback calculator is downplaying this by about 45% using approximately 15,500 hrs for interval.
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