Sunday, April 2, 2017

800 Lumens LED Bulb Illumination to Side vs. End-On

What shall I do with an old two-bulb lampholder now replaced by a wonderful Lighting Science 6" Glimpse LED disk light? I found it with two antique clear-glass incandescent bulbs, 150 watt and 60 watt, throwing ruinous heat and adequate light in a small hallway. The interesting 150 watt bulb died from a little jostling, before I could use it in comparisons. 

Ah so! I can compare sideways vs. end-on illumination from a couple of 800 lumens LED bulbs of current technology. Above, a non-dimmable Utilitech. Below, an Ecosmart. Both, made somewhere in China.

These bulbs will be at RHS on my comparison test stand. At LHS I have a first-generation Sylvania 70732, 900 lumens, 3000°K.

The combined illumination from two 800 lumens LED bulbs is not more than 600 lumens, far less than that of the 900 lumens LED disk light.

With the LED bulbs end-on to the screen upon porcelain lampholders, they far surpass 1600 all-directions lumens, but little of that is useful.

If an 800 lumens LED bulb is sideways on the ceiling or in a lamp is sideways to your book, expect it to yield only 300 lumens of practical illumination. Throwing away 60% of the light is a bad idea. We must learn to employ LED lighting in a natural downward direction like sunlight. I have offered similar comparisons in this blog several times. Much of this has been in challenge of leadership from the US Department of Energy, That leadership brought us silly and very expensive bulbs winning the US DOE L-Prize. 

Please look back at posts of this blog, found by  subject search, L-Prize.  

I think I am entitled to impatience with US DOE. Is anyone else watching this?

I am once again looking for leadership in residential LED light manufacturing, from Lighting Science

Here are installation details at the replaced two-bulb ceiling heater. Wiring made dangerous with fractured insulator material is such that weatherization must involve new cooperation between electricians, and access specialists with skills including plaster patching. We need the good LED disk lights too. I chose 6" Glimpse lights, 3000°K,  for my 850 lumens needs in this job. 

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