Many of our Title 24 clients have been asking us whether they can safely specify LED fixtures that would qualify as “high efficacy” lighting under Title 24. Could one conceivably create an entire lighting plan for a custom home using mainly LEDs, and if so, would it pass Title 24? Would it look any different to the untrained eye? Would it actually use less energy? Or, are LEDs better used as a supporting component in a diversified lighting plan rather than as the main workhorse? Are LEDs sustainable to manufacture? Do they use less power in a real-life installation, not just in the lab?
The answer to LEDs in California is a qualified but definite yes. There are definitely products out there that will comply with California’s energy codes, and we should see more coming to market this coming year. The issue is not the LED lamp itself, but the housing, because the fixture’s efficacy depends on the entire assembly.
As a designer, there’s some fine print to watch out for. To say a product “complies” with Title 24′s high-efficacy standards involves certification and documentation. There are many more products that would comply, but they’re made by smaller local manufacturers who can’t always afford the lengthy and expensive certification process. These demi-compliant products can be sold to retail consumers as after-market products, but without certification they wouldn’t pass a formal, by-the-book inspection. Manufacturers of lighting fixtures can test their own products of course, but to get a product certified means paying for an outside lab to test the products, and of course re-certification every time the code changes.
On the plus side, many building inspectors are favorably disposed towards LEDs and are willing to consider the products themselves on a case-by-case basis, as long as the product data is credibly presented. One of the lighting designers we spoke with, Henry Chu of Halogens Inc in Millbrae, CA, makes his own LED fixtures and is currently presenting some of his new products to local building officials for their feedback.
High Efficacy Definitions
Title 24 has various requirements and incentives to encourage the use of high efficacy lighting as measured by the amount of visible light emitted per watt of power consumed. The required threshold varies according to the number of watts in the luminaire, as distinguished from the lamp (bulb) itself.
Most people associate LEDs with the lamp component only, because they’re used to seeing them used singly as indicator lights on machinery. A luminaire is the entire assembed fixture, including lamp, ballast, housing, and connectors. Only luminaires can be high efficacy. It’s really the luminaire, or the entire fixture, that determines the efficacy – the bulb by itself is not enough.
- Under 15 watts, must have an efficacy of 40 lumens/watt
- Between 15-40 watts, must have an efficacy of 50 lumens/watt
- Over 40 watts, must have an efficacy of 60 lumens/watt
LED Fixtures: Your Efficacy May Vary
The problem with lack of standardization in LED fixtures is that the lumens per watt can vary. Some LED fixtures – if properly certified by the manufacturer – would indeed qualify as high efficacy under Title 24. The lighting designer really has to know both the components and the product. It’s possible to have two cabinet runs of different lengths in a kitchen that both use the same LED product, where a short run under 15 watts would qualify and the other longer one over 40 watts would not.
“LED lighting market is very fluid and all over the map with respect to energy efficiency, controllability, and color quality,” observed Ed Cansino, a lighting designer whom we interviewed a few months ago on Green Compliance Plus. “Still no standards in sight. Therefore, every product must be evaluated for suitability on a case by case basis.”
How Long Will LED Fixtures Last?
What’s the life expectancy of LEDs? “Lots of claims”, says Chris Primous of Permlight, an Original Equipment Manufacturer supplying LED parts to other lighting manufacturers. “Remember that LEDs don’t fail the way incandescents do, all at once. They just get dimmer over time.” A general rule of thumb is 30,000-50,000 hours at 70% intensity, meaning that after 50,000 hours of use the LED would still be guaranteed to produce at least 70% of what it did when it was new.
“LED lighting still has a long way to go,” says Hiram Banks, a San Francisco lighting designer recently profiled on our sister blog, The Architect’s Take. Product unknowns include optimal operating conditions and product life. “Most data we have is hypothetical based on lab studies. There are not many long-term studies because it has not been around long enough. So, when scientists and manufacturers say that white LED lighting has a lifespan of over 40 years, they are saying that with hypothetical data from the lab. There are many factors that determine the life of the LED light source, and they are becoming more evident as LED installations start to age. For example we have just learned that LED lighting needs a lot of air circulation and does not like heat, which can kill it in less than a year! We do not know if over time the light output starts to diminish as in most other light sources, or if the color starts to change.”
Creating A Good White Light
The temperature of the light indicates whether it’s warm (yellowish) or cool (bluish) measured in Kelvins (K), using sunlight as the ideal or standard. Red-orange light at sunrise is 1800K; a single 100W Incandescent light bulb is 2850K; and an overcast sky is around 6500K. Another component of white light is its spectrum. A light source’s Color Rendering Index (CRI) measures how true or realistic colors will look under the light source. A white light made up of three pure wavelengths will not have the same rich color rendering as a continuous-spectrum white light.
There are three ways to make white light using LEDs:
- Phosphor-coated blue LEDs are the most common
- You can also use an ultraviolet LED chip with a phosphor coating
- You can mix red, green, and blue LEDs
Most white LEDs are actually blue LEDs with a phosphor coating. These phosphors can vary, and the quality of the phosphor is what determines the quality of the resulting white light. It’s also possible to use “warmer” phosphors, which result in a warmer looking white. Some manufacturers like Cree LED Lighting are creating fixtures that utilize more than one of these techniques, and they may include amber, red, or orange LEDs inside larger arrays of a single fixture. Warmer white light looks better to our eyes, but with LEDs, the cooler the temperature, the higher the efficacy.
Are LEDs Really Eco-Friendly and Sustainable?
LEDs are touted as sustainable by environmentally minded consumers because they don’t contain mercury the way CFLs do, and they consume less energy than an incandescent. That doesn’t mean they’re perfect, though.
“We just recently found out about the ‘lack of sustainability of LED’ products a few months ago at the IALD convention. It has become a very hot topic, because of all the color variations, high price, and supposed long life,” says Hiram Banks. “Fluorescents are not ‘green’ because of the mercury in the lamp, but unlike LEDs, which require a lot of waste or bad product to make a few good products, the fluorescent lamp is good to go for each one manufactured.”
Banks explained what was so wasteful. “Currently LED manufacturers (about 5 major companies) will only sell entire bins/batches of LED’s to lighting manufacturers. The lighting manufacturers must sort through these purchased bins to individually pick the best white LEDs and discard the rest-typically these are sold on the third market to cut-rate LED manufacturers, whose LED’s are very blue/purple.” (Chris Primous of Permlight clarified the binning for me as follows: products are sorted into bins by range, with a 200-300K difference within a single bin.)
Banks went on: “The amount of waste is enormous, which is one of the reasons why LED lighting is so expensive. And believe it or not, the LED’s are bin selected by the human eye as there is no machine or device yet available that can accurately pick the same white color. ” Apparently, our eyes can’t do it, either, which is one reason why color variation continues to be a problem for LED fixtures.
How do LEDs look in residential lighting designs?
I asked Hiram Banks whether he’d used LEDs and how those projects came out. “We do not accept different color variation, especially given the high cost of the installed product,” Banks responded. “For our projects that have LED, mainly in long continuous runs, we are requiring them to install the same batch/bin produced in an effort to get the color correct. And on some of our jobs the LED manufacturer has to come back and pay to replace certain lengths of LED that do not match.”
“Each LED manufacturer has their own Kelvin Temperature curve or standard that they adhere to, and we have samples from each LED manufacturer, so we can match our other specified sources. So far, the better LED manufacturers have supported us by replacing LED that is not consistent or has different color variation, so our clients get the right product in the end. The only problem I have is the amount of waste involved… We are now taking a different approach to minimize the waste such as requiring all the runs be in the same batch/bin. This has helped tremendously.”
What can you do with LEDs?
The very lack of standards is also a driver of diversity when it comes to fixture types and designs. At Henry Chu’s shop we saw a good sampling of products and saw for ourselves the color quality. LED-based desk lights, spots and strip lights seemed to work well, and came in both “warm” and “cool” whites. Both the color rendering and edge crispness were surprisingly good – proof that quality components make all the difference. The white light was worlds apart from the dim, grayish “white” from the cheaper LED flashlights and desk lights.
Chu showed us an LED-based MR-16 equivalent that uses the directional nature of LEDs, and produces an almost-halogen equivalent at a fraction of the power consumption. This was a 3-watt model that can replace the MR-16, with its own driver and airflow built right into the base of the fixture. The cost? $25. Chu also showed us flexible LED strip lighting. And… many of Chu’s products were fully dimmable, and compatible with low-voltage wiring.
(We’ll do a follow-up article with more information on some of these products, with photos.)
Links for Further Study
- Interesting page from Light Emitting Diodes.org, all sorts of wavelength data for LED white light sources.
- Excerpts from a Californa Energy Commission PDF slide show: Title 24 2008 Changes to Residential Lighting Standards
- 3 Way Labs, maker of the “Cubatron” series of programmable displays
- Litefuzion, a UK-based company doing interesting LED lighting designed fixtures
- Case study from Future Group Lighting Design, also in the UK
About the author
Rebecca Firestone has been working in the Bay Area since 1998 as a technical writer, business content developer, architectural filing lady, marketing director, and sorcerer’s apprentice.