Typical Examples of Luminous Efficacy

I posted this on my Architectural Lighting Blog and since LEDs have been making the new in terms of luminous efficacy (lumens of light output per watt of power consumption), I figured I’d post it here too.

Borrowing a page (almost literally) from wikipedia here are some typical luminous efficacy numbers for various light sources since this seems to come up in lighting circles.

Luminous Efficacy & Efficiency Examples

Category	Type	Overall luminous efficacy (lm/W)	Overall luminous efficiency
Combustion	candle	0.3	0.04%
Incandescent	5 W tungsten incandescent	5	0.7%
	40 W tungsten incandescent	12.6	1.9%
	100 W tungsten incandescent	17.5	2.6%
	glass halogen	16	2.3%
	quartz halogen	24	3.5%
	high-temperature incandescent	35	5.1%
Fluorescent	5–24 W compact fluorescent	45–60	6.6%–8.8%
	34 W fluorescent tube (T12)	50	7%
	32 W fluorescent tube (T8)	60	9%
	36 W fluorescent tube (T8)	up to 93	up to 14%
	28 W fluorescent tube (T5)	104	15.2%
Light-emitting diode	white LED	26–70	3.8%–10.2%
	white LED (prototypes)	up to 150	up to 22%
Arc lamp	xenon arc lamp	30–50	4.4%–7.3%
	mercury-xenon arc lamp	50–55	7.3%–8.0%
Gas discharge	high pressure sodium lamp	150	22%
	low pressure sodium lamp	183 up to 200	27%
	1400 W sulfur lamp	100	15%
Theoretical maximum (monochromatic 540×1012 Hz, approx. 555 nm, green)		683.002	100%

If you want a good explanation of luminous efficacy, click here read the full definition at wikipedia

LED Display Case Lighting

Here’s a case study (uggh!Pardon the pun) in the works:

Our engineering department and myself would be very interested to get any feedback you might have on tackling the issue of shelf lighting (i.e. under shelf lighting) for product illumination on low-clearance shelves in a display case. The problem is this particular customer wants uniform or near uniform illumination of the top and front face of the product from shelf to shelf when the clearance between shelves is about 10 inches or so. They currently use and are not happy with fluorescent lighting which have a short life cycle in a heated environment and cannot be adjusted for color-temp or dimmed etc… so they want to switch to LEDs. When your product is so close to the lights, what is the best way to spread the illumination across the top and front face? Have any of you done something similar? We have our own thougts on this but would love to get your’s.

Here is a 3D Sketchup render (click to shoot over to my Architectural Lighting blog for a quick article about Sketchup and the Kerkythea Renderer) of the type of case (typical, not exact) this would be employed in:

Click thumnail to view full size image

..and here is the exact same Sketchup 3D model and scene rendered in Kerkythea:

Click thumbnail to view full size image

Technorati Tags: leds, led modules, accent lighting, display case lighting, engineering lighting, light engineering, color changing light, color cycling light, rgb leds, color leds, light design, designing with light, lighting design, led display case lighting, engineering case study, led case study, led projects, projects with leds, sketchup, google sketchup, 3d software, 3d rendering, architectural visualization, visualization software, 3d rendering software, lighting design software, lighting visualization software, kerkythea, kerkythea rendering system, 3d rendering, interior lighting, light modeling, 3d modeling, lighting design tools, 3d engineering, 3d drawing, 3d models