Electric-Light
Senior Member
Cheaper, but short lived LED lamps are now commonly available. They are especially suited for residential use as well as commercial and industrial applications where annual operation time is 1,000 hours or less but subject to short and frequent cycling that do not play well with CFLs. Value TLEDs are great for sheds, utility closets where cold temperature performance is valuable but they're not suitable for traditional applications for fluorescent lamps where they they burn for thousands of hours a year.
Lumalux is a HPS. MetalArc is a MH.
This is the lumen maintenance performance for now outlawed, obsolete F40CW using traditional phosphors. From 1994.
F40 was rated for 20,000 hours with 3 hours to the start. Many retail and office applications extends this to 30 to 36K.
The best selling LED is the builder grade or "value" but it's an entirely different class of product as you can see from the graph. It is a good fit for relatively low hour applications with usage pattern that is destructive to fluorescent lamps such as individual apartments. The poor durability makes the energy performance worse as you need more watts installed to sustain the same output. For areas that get 4,000+ hrs a year and it is considered acceptable to start at 2,000 lumens that degrade to 1,400 per lamp, the better energy saving approach is to start off around 1,500 lm with lamps with very low depletion.
TLEDs that can hold their ground against super premium T8, the cost is something else.
Examples of value LED. Cost competitive in that they cost about the same as ultra premium fluorescent while being an LED but 36K hours to L70 makes it not perform as well for long hour applications.
The lowest end of modern LEDs are only rated for 11,000 hours to 30% light loss. The 800 lm sold as 60W equivalent and 10 times the life of incandescent fades to 560 lm.
That's about 2.5 years for dusk-to-dawn and I expect some to experience ballast failure just like CFLs. These specifically disallow enclosed fixtures.
This was the standard T8 23 years ago. It's self explanatory that allowing decay worse than two decades ago is not savvy. You need to have initial lumens that is 1.42 times the design lumen of a T8 system. This puts the break-even point for LEDs at 125lm/W or more. When you're using high degradation lamp source like MH and LEDs in fixed output, its a compromise between having a high initial over illumination or choosing a shorter re-lamp interval. The system could use dimming ballasts and increase the output periodically to counter LED degradation
Lumalux is a HPS. MetalArc is a MH.
This is the lumen maintenance performance for now outlawed, obsolete F40CW using traditional phosphors. From 1994.
F40 was rated for 20,000 hours with 3 hours to the start. Many retail and office applications extends this to 30 to 36K.
The best selling LED is the builder grade or "value" but it's an entirely different class of product as you can see from the graph. It is a good fit for relatively low hour applications with usage pattern that is destructive to fluorescent lamps such as individual apartments. The poor durability makes the energy performance worse as you need more watts installed to sustain the same output. For areas that get 4,000+ hrs a year and it is considered acceptable to start at 2,000 lumens that degrade to 1,400 per lamp, the better energy saving approach is to start off around 1,500 lm with lamps with very low depletion.
TLEDs that can hold their ground against super premium T8, the cost is something else.
Examples of value LED. Cost competitive in that they cost about the same as ultra premium fluorescent while being an LED but 36K hours to L70 makes it not perform as well for long hour applications.
The lowest end of modern LEDs are only rated for 11,000 hours to 30% light loss. The 800 lm sold as 60W equivalent and 10 times the life of incandescent fades to 560 lm.
That's about 2.5 years for dusk-to-dawn and I expect some to experience ballast failure just like CFLs. These specifically disallow enclosed fixtures.
This was the standard T8 23 years ago. It's self explanatory that allowing decay worse than two decades ago is not savvy. You need to have initial lumens that is 1.42 times the design lumen of a T8 system. This puts the break-even point for LEDs at 125lm/W or more. When you're using high degradation lamp source like MH and LEDs in fixed output, its a compromise between having a high initial over illumination or choosing a shorter re-lamp interval. The system could use dimming ballasts and increase the output periodically to counter LED degradation
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