LED Lights for Home

Going Green is a relatively new term and many of us are trying to do our part by purchasing compact florescent bulbs replacing the rather inefficient Halogen or Incandescent light bulbs.  CFL bulbs are the way to go when it comes to energy saving efficiency, or is it.  Some cities in the United States are replacing CFL with solid-state technologies from CREE or Phillips-Luxeon for offices, bus-stops, street lighting, traffic signals, etc.  These are just some prime examples of what local city governments are working on to cut down electricity consumption.

Some homes I have seen in Southern California near Newport Beach have gone "Green" by using LED lightning technology on the landscape and the interior lightning of the house.  My own house falls under that "Green" category where I replaced every light with CREE LED lights to reduce my electricity consumption and increase efficiency in both the lighting and heat department.  The only downside that I can see is the initial cost to go solid-state lighting.  LED technology is just about everywhere ranging from that clock-radio, Microwave oven's clock display, the backlighting in laptop and desktop screens, to the billboard displays in Las Vegas.  Many of the tactical and everyday household flashlights use LED technology over halogen or xenon.  The cost of using LED bulbs over traditional Halogen, Xenon, and Incandescents is a little bit higher, but the energy savings alone should justify this.

I know Germany is banning the sale of Halogen and Incandescents in favor of more energy efficient technologies such as CFL and LED.  More to the point, the government offers subsidies to go energy efficient lightning.  Having lived in Germany for about a year, I came to understand the reasons for going "Green".  Going "Green" in the United States means making very hard choices to the degree that it interferes with the day-to-day activities of life.  In Germany though, this isn't the case.  The degree is subtle, but is quite drastic since the implementation itself isn't self evident.

LED illumination is can be rather cold to somewhat annoying, but with advanced strides in the control of color temperature with newer and better materials, the light temperature approaches some of the best warm tinted CFL (2900 to 3600K).  Color Temperature essentially is how we perceive white light and the higher the number, the colder or to our eyes, the more bluish tint we see in the given spectrum of light.  Warm White Color Temps allows for a pleasant illumination of the room and surroundings while reducing eye strain when reading a book or working with pictures (something of that sort).  Cold Color Temps allow for sharper contrast when also looking a photographs or something that requires careful attention to detail, but allows for greater strain on the eyes due to the colors being brought out by the higher degree of white LED illumination.  Many people that I have spoken to feel that colder color temps allow for them to see more at night, however that is because our eyes react to the shorter wavelengths of light (red is long vs. blue is short wavelength).  Neutral color temperature of 4300K (CREE LEDs are mainly aimed at a range of 4000 to 4600K except for their Warm White variants which lean toward 2900K) provides the balance of the sharper contrast of the cold while providing the pleasant and less eye straining feeling of the warm white balance.

To give a comparison, CREE LED provided me samples of their LED bulb drop-ins to compare with CFL of equivalent light output.  Most CFL bulbs lean toward 5000K, which is slightly above neutral balance white while still providing sharp contrast of colors.  The lowest consumption bulb in the CFL arsenal is a 7-watt unit from Felt Electric, which provides about 45-watts of 5000K light with an integrated diffuser (the diffuser allows for an even spread of light within a room without the hotspots commonly associated with non-diffused sources).  The CFL requires about thirty seconds to reach full brightness (longer if the room is colder than 40-degrees Fahrenheit - room size is 10 by 12' with 10' ceiling) and once reached, the light bathes the room softly with a near 120-degree flood.  The integrated diffuser allows for the light to cover the entire room without any hotspots of any kind.  Using a Newport Corporation Light meter, I decided to measure the amount of light at its highest point (most illumination) and the results after careful positioning was about 300-lumens (+/- 50-lumens at 9' 10" away from source), which is not bad at all considering the power consumption and perceived wattage output.  Now using a CREE LED sourced drop-in which consists of a single 3-Watt unit (XLAMP-XR-E through piped optics at 60-degree flood) and the results were astonishing.  Instant startup and even though the light illumination is through piped optics providing a 60-degree flood, there is quite a bit of spill.  A hotspot was created no doubt but the spot created was within the 60-degree range of the intended area with a significant degree of side lightning to fill the room quite nicely.

Same distance from source to the floor, the 3-watt CREE LED drop-in delivered 420-lumens (+/- 80-lumens at 9' 10" with piped optics and diffuser) and bathe the room rather softly at 4500K Neutral White Color Temperature.  Heat output is virtually non-existent with both light sources so no need for additional cooling or ventilation in the room.  The actual power consumption of the LED is actually lower than with CFL since the latter type requires considerable amounts of electricity for a short duration to light up the gases in the bulb.  Unlike filament bulbs, CFL contains mercury gas and phosphor to glow as it were (mercury illuminates in long-wave UV and this excites the white phosphor in the CFL tube to create the white light we see) and requires a bit of time to reach the intended brightness, color temperature, and wattage output.  LED bulbs also use phosphor but in a sealed optically transparent epoxy and in very small quantities plus a minute amount of UV all in a package much smaller than what CFLs use.

The primary difference between LED and CFL is that the former technology requires the use of DC while the latter is AC driven.  Most drop-in LED units, whether it is from CREE, Nichia, and Phillips, feature AC to DC drivers and are heat-sinked to prevent damage to either the driver or the light source.  My home however, I decided to have custom lighting throughout the interior so dedicated AC-to-DC drivers are used with line-condition and digital dimmers to allow for smooth and gradual dimming of light.  Since LED illumination is DC driven, flickering or high-speed strobing effects aren't present unless otherwise specified.  High-quality lighting fixtures of today from Halo, CREE, LUXEON, etc, feature high-quality AC-to-DC drivers that allow for zero-flicker dimming or overall lighting.  Most of these non-drop-in types consume an average of 12-watts and deliver about 650 to 800-lumens of light, which is about the same as a 55-watt Halogen Flood or 30-watt CFL (Halo uses CREE LED and the fixture uses a 60-degree diffused lens flood).

The primary disadvantage with solid-state lighting is cost as mentioned in the earlier paragraphs.  CFL lighting is rather efficient, but if one were to really become both "Green" and efficient, solid-state lighting would be the way to go.  Try it out and see for yourselves to see if you like the change.

Thanks for reading and have a great week, month, year, etc.