LICODA

• Lecture Power Point
• Printable Notes
• Reading Due: Architecture of Light - Chapters 16, 30 & Part IV

I just came across another great article in Architectural Lighting Magazine by James Benya titled “Controlling Glare”. The article touches on luminance ranges and how they impact a lighting specifiers’ daily life. The second half of the article addresses daylighting and the measures used to mitigate the high contrast and luminance associated with daylit space.

I encourage you to read this article.

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

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.

The Las Vegas Section of the IES (Illuminating Engineering Society) invited me to speak at their November General Meeting. The topic I presented was LEED and I summarized the program while emphasizing a few credits that pertain to lighting and electrical disciplines.

Visit the portal page by clicking here and viewing the presentation in your web browser.

While doing some research on lighting control, I ended up comparing options and features of various systems. One of these particular features was Open Loop vs. Closed Loop based lighting control systems. I found myself trying to remember the difference between the two and realized that some of you may benefit from my re-investigation of this topic. The basic difference between the two systems is the use (or lack thereof) of feedback.

Open Loop (or non-feedback, according to wikipedia) refers to a system that does not use feedback to gauge control of the medium.

Closed Loop refers to a system that will use feedback to determine the control state of the medium.

In the architectural lighting world, the controlled medium would be electric light. Closed loop lighting control systems will monitor light levels and adjust the output of the luminaires based on the light level produced by the same luminaires. Open loop systems will simply control the output of the luminaires based on other factors (time of day, amount of daylight, etc).

Daylight controls typically come in open loop and closed loop varieties. As the system monitors the amount of daylight, the output of the electric light is adjusted accordingly. A closed loop daylight control system will monitor the amount of daylight and the amount of electric light to adjust the electric light to provide a continuous level over the course of time. Closed loop systems usually incorporate dimmable luminaires so the light output can be fine tuned accordingly to meet the desired target through a range of available daylight. Eventually, most open and closed loop daylight control system will measure enough daylight to minimize electric light output and maximize energy savings.

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.