101 on LED's and Lighting
This article in the Economist's Technology Quarterly made me remember back about the path we took in understanding where LED lighting is now and how we could use it to meet our needs.
We found it was a good solution for both meeting Title 24 lighting requirements and cove lighting requirements on a recent project. 2005 Title 24 changed how we look at illuminating the homes we produce.
Look for LED's to start to encroach on the lighting turf in homes currently mandated to be compact fluorescent. They range from 40 to 100 lumens/watt in the color spectrum most widely desired with a 50,000 hour projected life (25x longer than incandescent).
LED's are a fast moving technology, and as the technology moves down the price curve, I look to use this technology in more of my projects. I don't know a single designer who is enthralled by the current code required lighting options (basically compact fluorescent (CFLs)). LED's may be a welcome alternative, and they will change how fixtures look--can't wait to see how these are adapted.
California's Title 24 energy code basically mandates that 75% of the light fixtures in a kitchen be high efficacy, and the balance of lighting in the home either be high efficacy (above the solid line in the chart above) or controlled by an occupant sensor or dimmer switch.
The big change I notice are occupant sensors in bathrooms, a higher number of compact fluorescent fixtures in kitchens and all lighting circuits with dimmer switches.
The trick I found about LED's is to get the light warm enough. So you need the fixtures to produce greater than 60 lumens/watt in a 3000K color range (warm white) and a CRI (color rendering index) of >90. Same goes for CFL's if you are evaluating those.
If you want to geek out on this, the relative cost can be explained by downloading and playing with this spreadsheet (hat tip to ProductDose.com) that compares incandescent, CFL's, and LEDs.
