LICODA

I found a great article in the July 2007 issue of Architectural Lighting magazine. The article is about daylight and glazing and is written by lighting icon James Benya. The author does a great job of defining and describing different type of glazing and their interaction with daylight. This is a must read if you are involved with any type of glazing specification.

The links to the article are below:

Part 1 -http://www.archlighting.com/industry-news.asp?sectionID=0&articleID=554032

Part 2 -http://www.archlighting.com/industry-news.asp?sectionID=0&articleID=623836

Part 3 - http://www.archlighting.com/industry-news.asp?sectionID=0&articleID=626636

The truth is, from a lighting standpoint, we don’t know the truth. The lighting industry has been pleading for a set of standards to be published which allows light emitting diode (LED) sources to be compared to traditional lighting sources.

Performance data is available for LED sources, but some of the methods of measurement and the technology behind the production of light, potentially skew the analysis in favor of LED products.

Don’t get me wrong, LEDs are a great new lighting technology that raises the bar on source efficiency and allows light to be presented in unique ways. However, it pains me to see this source misrepresented as the end-all, be-all solution for lighting performance.

Most experts will agree that LEDs do have a significant lifespan. But just how significant is it. The life of a traditional light source is determined with 50% of a collective sample fails to product light (burns out). The problem with LEDs is they never really stop producing light. LEDs will continue to degrade and produce less and less light, until output is unusable. But, what constitutes unusable? I have heard reports of LEDs producing 50% of their initial output (amount light generated when first energized) after only one year of operation. These products may continue to produce light, but if at least twice the amount of product will be required for the majority of the systems life, is this being factored into the efficiency equation? Traditional lamp systems feature standardized testing to monitor the output of a lamp over it’s life cycle.

Another measure of performance for light sources is efficacy. Efficacy indicates the amount of light output (lumens) per energy unit consumed (watts) - the more lumens produced per watt, the higher the output performance of the lamp. This measure ensures we are comparing apples to apples when talking about source performance. There have been reports of LEDs having extremely high efficacies but little information about the method used to conduct the test. In some instances, these LEDs only product light for mere instant at the measured efficacy calling into question the practicality of the measurement. Once again, this exemplifies the need for standards of performance for LEDs.

Conversely, LED sources do provide for luminaire designs that tend to allow more initial lamp lumens to leave the luminaire for increased luminaire efficiency. As always, lighting specifiers should evaluate the total efficacy of the lighting system during analysis, before making any decisions.

Until standards are available, manufactures have been encouraging lighting designers to verify first hand, the performance of LED based products. Make sure you don’t get caught in the whirlwind and force your client into a solution simply because it is the hottest topic in the media. Targeted terms like “energy efficient”, “long lasting” and “high performance” can be misleading due to their vague definitions of accuracy. Be sure you know what your getting into before using these terms to establish your design criteria.

CNN.com ran an article describing a study that states individuals who work night-shifts may be more susceptible to cancer. The study clearly indicates that more research is required, but the World Health Organization and the American Cancer Society is listing night work as a possible carcinogen. You can view the article by following this link.

The study believes the disruption of sleep in darkness throws the bodies circadian rhythm off track and my lead to the infiltration of foreign body on the cells. Published information such as this could have a profound impact on industrial companies.

As noted in the article, if you have a high maintenance application that requires long lamp life, then the high initial cost of an induction lamp may be justified for the application.

The basic technology for induction lamps is not particularly new. Essentially, an induction lamp is an electrodeless fluorescent. Without electrodes, the lamp relies on the fundamental principles of electromagnetic induction and gas discharge to create light. The elimination of filaments and electrodes results in a lamp of unmatched life. Lasting 100,000 hours or 25 years, this system can outlast 100 incandescent, five HID, or five typical fluorescent lamp changes.

Based on these well-known principles, light can be generated via a gas discharge through simple magnetism. Electromagnetic transformers, which consist of rings with metal coils, create an electromagnetic field around a glass tube which contains the gas, using a high frequency that is generated by an electronic ballast. The discharge path, induced by the coils, forms a closed loop causing acceleration of free electrons, which collide with mercury atoms and excite the electrons. As the excited electrons from these atoms fall back from this higher energy state to a lower stable level, they emit ultraviolet radiation. The UV radiation created is converted to visible light as it passes through a phosphor coating on the surface of the tube. The unusual shape of an induction lamp maximizes the efficiency of the fields that are generated.

Although it is not breakthrough science, until recently, it has not been so commercially viable. New developments have broken down the barriers of costs and technological setbacks, such as EMC interference, lumen depreciation, ability to dim and a useful range of available wattages. Today, its obvious benefits make it the clear-cut choice for many lighting applications over traditional light sources.

For more information on how inducting lighting works, visit the fluorescent induction lighting section of the electrodeless lamp entry at Wikipedia.com.

Light Emitting Diodes (LED) are certainly the buzzword in lighting. These sources offer somewhat efficient lighting with long lamp life for maintenance and a small form factor for unique applications. What many people don’t realize is that LED are not the ultimate answer in lighting. Currently, LEDs are more efficient than incandescent based sources, but not as efficient at fluorescent or HID technology.

LEDs are diodes. Diodes are used in electrical circuit to restrict the flow of current to one direction. As diodes impede the electricity, they release energy, sometimes in the form of light. Depending on the chemical composition and physical make-up of the diode, certain wavelengths of light are manufactured.

Diodes utilize a semiconductor charged with electrons, which passes electrons through this material when an electrical current is applied. As the electrons pass from the negative charge to the positive charge, energy is given off in the form of visible light.

Because LED do not feature electrodes or filaments light other sources, the life of the product is dramatically increased and great for long life applications.

Although I am familiar with the CIE color chart, I have never really understood how this chart represents color and the visible spectrum, until now.

The article located at http://www.cs.bham.ac.uk/~mer/colour/cie.html allowed me to understand the basis of this system, truly for the first time.

Color Psychology may not be at the top of the list when it comes to lighting subjects, however, the two are related. Without light, color most certainly does not exist.

I tracked down the following color psychology and association information for my students. This information, coupled with the information being covered in class regarding lighting psychology, should provide design students and broad understanding of what should be considered while designing a space.

The following information comes from an article written by David Johnson and hosted on www.infoplease.com/. You can view the entire article at http://www.infoplease.com/spot/colors1.html.

Black - Black is the color of authority and power. It is popular in fashion because it makes people appear thinner. It is also stylish and timeless. Black also implies submission. Priests wear black to signify submission to God. Some fashion experts say a woman wearing black implies submission to men. Black outfits can also be overpowering, or make the wearer seem aloof or evil. Villains, such as Dracula, often wear black.

White - Brides wear white to symbolize innocence and purity. White reflects light and is considered a summer color. White is popular in decorating and in fashion because it is light, neutral, and goes with everything. However, white shows dirt and is therefore more difficult to keep clean than other colors. Doctors and nurses wear white to imply sterility.

Red - The most emotionally intense color, red stimulates a faster heartbeat and breathing. It is also the color of love. Red clothing gets noticed and makes the wearer appear heavier. Since it is an extreme color, red clothing might not help people in negotiations or confrontations. Red cars are popular targets for thieves. In decorating, red is usually used as an accent. Decorators say that red furniture should be perfect since it will attract attention. The most romantic color, pink, is more tranquilizing. Sports teams sometimes paint the locker rooms used by opposing teams bright pink so their opponents will lose energy.

Blue - The color of the sky and the ocean, blue is one of the most popular colors. It causes the opposite reaction as red. Peaceful, tranquil blue causes the body to produce calming chemicals, so it is often used in bedrooms. Blue can also be cold and depressing. Fashion consultants recommend wearing blue to job interviews because it symbolizes loyalty. People are more productive in blue rooms. Studies show weightlifters are able to handle heavier weights in blue gyms.

Green - Currently the most popular decorating color, green symbolizes nature. It is the easiest color on the eye and can improve vision. It is a calming, refreshing color. People waiting to appear on TV sit in “green rooms” to relax. Hospitals often use green because it relaxes patients. Brides in the Middle Ages wore green to symbolize fertility. Dark green is masculine, conservative, and implies wealth. However, seamstresses often refuse to use green thread on the eve of a fashion show for fear it will bring bad luck.

Yellow - Cheerful sunny yellow is an attention getter. While it is considered an optimistic color, people lose their tempers more often in yellow rooms, and babies will cry more. It is the most difficult color for the eye to take in, so it can be overpowering if overused. Yellow enhances concentration, hence its use for legal pads. It also speeds metabolism.

Purple - The color of royalty, purple connotes luxury, wealth, and sophistication. It is also feminine and romantic. However, because it is rare in nature, purple can appear artificial.

Brown - Solid, reliable brown is the color of earth and is abundant in nature. Light brown implies genuineness while dark brown is similar to wood or leather. Brown can also be sad and wistful. Men are more apt to say brown is one of their favorite colors.

For more information on color psychology, visit Color Psychology written by Kendra Van Wagner and hosted on about.com

The following is an excerpt taken from the wikipedia.com entry for color blindness.

There are many types of color blindness. The most common are red-green hereditary (genetic) photoreceptor disorders, but it is also possible to acquire color blindness through damage to the retina, optic nerve, or higher brain areas. Higher brain areas implicated in color processing include the parvocellular pathway of the lateral geniculate nucleus of the thalamus, and visual area V4 of the visual cortex. Acquired color blindness is generally unlike the more typical genetic disorders. For example, it is possible to acquire color blindness only in a portion of the visual field but maintain normal color vision elsewhere. Some forms of acquired color blindness are reversible. Transient color blindness also occurs (very rarely) in the aura of some migraine sufferers.

The different kinds of inherited color blindness result from partial or complete loss of function of one or more of the different cone systems. When one cone system is compromised, dichromacy results. The most frequent forms of human color blindness result from problems with either the middle or long wavelength sensitive cone systems, and involve difficulties in discriminating reds, yellows, and greens from one another. They are collectively referred to as “red-green color blindness”, though the term is an over-simplification and somewhat misleading. Other forms of color blindness are much more rare. They include problems in discriminating blues from yellows, and the rarest forms of all, complete color blindness or monochromacy, where one cannot distinguish any color from grey, as in a black-and-white movie or photograph.

Recently, a local IES presentation I attended about daylighting re-entered my mind. This was a presentation given in November 2007 by Michelle Boynton of Brummit Energy Associates, Inc. Among the many daylight related issues Michelle discussed, the methods of performance modeling really caught my eye.

Typically, daylighting analysis requires an investment in resources and time. Of the five performance modeling methods presented by Michelle, some could be implemented almost immediately and/or with minimal resources.

The five methods presented were LEED NC EQ.8 calculations, T24 Daylight Zone Mapping, Profile Angle Studies, Illuminance Calculations and Energy Studies. If you can get your hands on the LEED NC Reference Guide and familiarize yourself with Title 24 daylight zones (if you practice in the state of California, you are already familiar), you will see how easy these methods provide a quick analysis of a project’s daylighting capabilities.

For those armed with the ability to quick sketch, Profile Angle Studies may also indicate daylighting effectiveness efficiently. Bottom line, I was able to walk away from the presentation with new techniques that I could immediate begin to implement.

To review these methods and the rest of the daylighting presentation, you can view a .pdf copy here.

Author’s Note (added October 1, 2007): I came across another document outlining some daylight design tips (in addition to numerous other daylight design items). A .pdf version of the document can be found at http://www.informedesign.umn.edu/_news/mar_v03-p.pdf and appears to be published by the University of Minnesota.

The following design guidelines are taken directly from the article and include:

• Avoid direct sunlight and skylight unless needed for thermal comfort.
• Bounce daylight to create indirect daylight.
• Bring daylight in from above to obtain deeper penetration.
• Filter daylight into buildings.
• Use sustainable design principles.
• Maximize ceiling height to gain better light distribution.
• When appropriate, separate view glass from daylight glass.
• Determine whether daylight is primary or supplementary in lighting design.
• External control strategies offer best light and heat control. Combine strategies of external and internal controls area also practical and are becoming more common.
• Building geometry and space planning should promote, rather than preclude, distribution of daylight.
• Locate the maximum number of spaces near daylight through building massing and configuration.
• Create low contrast between window frame and adjacent walls to reduce glare and improve the vision experience. Splaying openings inward can increase distribution of daylight into rooms.
• Integrate building systems, including artificial lighting with daylighting through control systems.