Let there be light

Posted: December 27, 2011 in Being Green, Green Technology

I spent much of the weekend swapping out incandescent lights around the house – as many have burnt out.  Unfortunately incandescent lights are a standard fixture in most homes because of how inexpensive the upfront costs are (and they put in builders grade lights as well – not Philips or GE bulbs).  On average they will cost less than $3 a bulb (for a recessed lighting) and down to $.60 for a standard A series 60 watt lamp light bulb.

Various Bulb Shapes - Prices vary based on size / specialty / availablity.

However cheap they are upfront, they wind up costing significantly more in the long run due to extremely high energy usage.  Try to unscrew a bulb after its been on for several minutes and you’ll quickly learn how hot they get – and that is the crux with them as 90% of the energy they use is wasted in heat energy and not light output (lumens).  This is a reason why those little easy bake ovens use light bulbs to cook food b/c they are pretty efficient in making heat energy – not a good combination when in the summer you are trying to cool your house and have little heaters on inside it.

Thus grew the next stage of replacements – the CFL – (compact fluorescent lights).  I however saw these as a compromise as they often have mercury in them making them difficult to dispose of (or dangerous as it seeps into groundwater causing health concerns).  CFLs also give an artificial light (they are now much better and make a warmer light) and suffer from issues with dimming and expected life (they are supposed to last 3x – 4x longer than an incandescent).  Unfortunately with CFLs their biggest drawback is on/off cycling – they need to run for a minimum of 10 minutes to be operating at maximum effectiveness.  If you turn them on/off such as in a closet or elsewhere it significantly reduces their life more so than an incandescent bulb.  Thus the issue with them and the reason why most people will not adopt them (and I don’t blame them).  Where they really shine is in offices and other constant on environments – that is where they are superior to incandescent lights.

Still works after 3 years b/c was in constant on status.

So incandescent lights are extremely energy wasteful to product light and CFLs are a compromise and effective in only limited conditions.  Looking into the history, the incandescent light bulb was invented in the late 1800’s so we should have a 21st century solution and we do: the Light Emitting Diode’s (LED).  Here’s a simple fact sheet comparing them to incandescent lights (I’m ignoring CFLs).  LEDs use 80-90% less energy to produce the same amount of effective light output with little heat byproduct, they are dimmable, solid state and rugged, last 10x – 20x longer, its life is not effected by on/off cycles (even incandescent lights will wear out faster in this operation), they have spectrum light output from bright white to soft white, and they do not contain any harmful chemicals or materials.  Their only drawback is upfront purchase price.  They cost $10 a bulb for a standard lamp light 60 watt output compared to < $1 for incandescent.  However energy usage more than makes up for the LED’s higher price – just in 1 year if you have this light on for 3 hours every day you’ll save $6+ dollars in energy on the light bulb itself (not to mention not heating up air conditioned air in the house which makes your a/c unit run longer in the summer).  Check out this magazine article by Wired Magazine.

LED bulbs from Pharox - $10 and Dimmable (come in a neat package too).

What is even better than LEDs or any other light source?: Natural Light!  It is free, it is natural, it is healthy as our skin requires a certain amount of daylight to produce Vitamin D.  As some other projects going on I plan on adding a couple tubular sky lights around the house or small fixed translucent glass bricks in areas that the only source of light is a fixture.  I’d rather not need to turn on a light to see into a dark room I access frequently with < 30 second on times (think pantry or closet).  I did this with our garage adding garage door windows and two standard windows on the side and now do not need to turn on the lights to see – even at night as we have a street light outside.

Tubular Sky Light (even has a switch to close light source like a real light bulb)


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