Although LED’s are in being considered
for many architectural considerations , there are some facts about this emerging
technology that should be understood prior to assuming this to be the
replacement to the conventional light bulb.
Color temperature: Color temperature for LED’s are really narrow and quite cool in the “white format” they range from 4300°k to 5500°k.To many designers this is considered “cool white”.
Control: Dimming is possible with Led’s, however it is a current control and not a voltage control. This means that a standard dimming switch will not control it and special wiring needs to be installed in advance. It is possible, but requires some planning. Also another thing is that when you dim conventional point source lighting, this temperature “warms up”. This does not happen with LED’s. With the proper controls, it may be less bright, but no color or warmth will be achieved. If you want color variance, then you may need to go to RGB technology and that is another discussion.
Efficiency: contrary to popular belief, LED’s are almost the
same efficiency as reflectorized point source lighting (i.e. typical down light)
when Lumens per watt are considered. Perhaps a 10-15% variance is achieved, but
as of now it is not considered a major difference. When you consider that new
technology in fluorescent is now a minimum of 4 times more efficient at about 80
lumens per watt, this is also something to consider.
rendering: The color rendering of point source lighting is as
stated 100. It is the benchmark where all CRI issues are measured. Currently
LED’s are in the low 80’s which is good, but not fantastic when highlighting
colorful display items. High Tech Fluorescent is now reaching the high 80’s.
Operating cost: The primary concern with any lighting plan is the heat that the fixture generates. Heat is directly related to the number of watts consumed. The heat and watts affect the entire project because it consumes the electricity as well has a requirement to cool or condition the air of the space. As LED’s are slightly more efficient that standard point source lighting, they will contribute to the overall cost of operation in the long run.
Even the best point source lighting
sources seem to top out at 5000 hrs average life span if operated at design
voltage. This means operating a 12v lamp at 12vots and a 120v lamp at 120 volts
with no dimming. LED’s truly excel in this department as they last a minimum of
40,000 hrs depending on the output and color this can be greatly increased. It
is safe to say that when a project that is operating 24hrs a day, the
maintenance cost can be greatly reduced. When you look at 5 years versus 5
months for lamp replacement, it is a serious consideration for many commercial