The "80% energy savings" is because it produces 80% less light.

Thank you for your questions, jonr.

LED Lighting are lights which use light emitting diodes (LED’s) which are extremely energy efficient and long lasting. LED lights create less heat than traditional lights, which means they last for longer and it means your air conditioner doesn’t have to work as hard. LED lights are a relatively new technology and can help you save upto 80% on your lighting cost.

On the led tube lamp luminous efficacy, you maybe had a test or saw that the led tubes produce less than 80% of light the manufacturer claimed years ago. Fourtunately there is a move towards certification. The development of standards gives confidence that led tubes as a fluorescent subsitute will eventully be subject to a standard, such as Energy Star.

Notwithstanding exaggerated performance claims, lamp luminous efficacy is imporving. Efficacy is measured of the amount of light produced per watt of electricity consumed. New fluorescent lighting typictally has an efficacy of 80 to 100 lumens per watt.

Our experience in testing LEDs over the last two years has shown a great improvement in LED efficacy over that time. At current rates of improvement , it is reasonable  to assume that an efficacy of 150 lumens per watt will be achieved before 2015, and that lamps will be available with an overall of at least 120 lumens per watt. This would meant that and 18 or 20 watt LED tubes could be confidently used to substitute a 36 watt fluorescent with no loss of light output.

I agree that LEDs (and fluorescents) will continue to improve. But for now, we need to use the figures from what is available. In this case, 700 lumens vs ~3100 lumens for a good T8. LEDs can have a long life and good low temperature performance.

Posted By jonr on 29 Jul 2010 07:45 AM
I agree that LEDs (and fluorescents) will continue to improve. But for now, we need to use the figures from what is available. In this case, 700 lumens vs ~3100 lumens for a good T8. LEDs can have a long life and good low temperature performance.

This is a 2-footer not a 4 footer, so it's really only a 50% reduction in raw lumens, not 80%.  But it's about half the power of a 24" T8 (17W) too, so it's no real improvement in efficiency from a lumens/watt point of view.

Depending on the type of fixture & fixture-efficiency, it MIGHT be a reasonable replacement. LED photometrics are typically highly directional.  In a low efficiency highly directional fixture it might even be an improvement in visual efficacy over a 17W T8, but don't count on it.  It all depends on the app.

They do release less light, but it is mostly light frequencies that are not visible anyways. See Compact Fluorescents at this site for a full explanation of how CFLs use energy.

LED could be the best replacement for fluorescent lights because of its durability and lighting efficiency.

I am building a new building, for myself, I want a pleasant energy efficient light system. I am interested in LED, but what I find is LED to retro-fit in existing incandescent and now fluorescent fixtures. What is out there for LED fixtures, but should I even use them?

Brad;

I am also interested in LED's but as you have probably found they are not quite affordable, I have outfitted my entire home with flourescents until the tecnology and cost improves

I was even thinking of LED Christmas lights or rope lights, but they would only be good for accent lighting, unless there was a lot.

Posted By ICFconstruction on 20 Sep 2010 08:19 PM
I was even thinking of LED Christmas lights or rope lights, but they would only be good for accent lighting, unless there was a lot.

rope lights make excellent accent lighting on plant / pot shelves, I use a 6ft. rope light recessed under my fireplace mantle

Be patient - Toshiba is about to go NA wide through the big box stores with LED replacement lamps and new installation products. They have indicated they will be competative with compact fluorescent.

http://www.toshiba.com/lighting/group_display.jsp?id1=42

Posted By Steve McMahon on 15 Oct 2010 03:20 PM
Be patient - Toshiba is about to go NA wide through the big box stores with LED replacement lamps and new installation products. They have indicated they will be competative with compact fluorescent.

http://www.toshiba.com/lighting/group_display.jsp?id1=42

I dunno- they're all  running about 35 lumens/watt, near as I can tell (I've only looked at the specs for a few), most barely more than half the luminous efficiency of CFLs. 

I'll wait for the L-prize entries to show up in the marketplace (SFAIK it's a Philips-only show for now.)  At least there you'd be approaching T8 linears on overall efficiency, and beating current run-of-the-mill CFLs.  Since LEDs will last a very long time, locking into something early that's only half the efficiency seems silly.  By the time your 2x as efficient CFLs burn out there should be more than just the high-efficiency Philips A-bulb LED out there.

But then again, if nobody buys current versions of LEDs it slows development of the technology. I s'pose that's why they put up the L-prize in the first place...