Daylight factor, a metric used to express the availability of daylight in a space, is explained clearly here.
Webinar: “Daylighting: Lighting Every Building Using the Sky” Presented by: Energy Center University in partnership with the Daylighting Collaborative, presenting faculty Abby Vogen Horn, Senior Project Manager, Energy Center of…
Webinar: “Daylighting: Lighting Every Building Using the Sky”
Presented by: Energy Center University in partnership with the Daylighting Collaborative, presenting faculty Abby Vogen Horn, Senior Project Manager, Energy Center of Wisconsin
When: March 18, 2009 at 1:30pm – 3:00pm CDT
What: Integrated daylighting design is the key to whole building energy savings and a successful sustainable design. This 1.5 hour webinar examines critical daylighting design techniques and considerations. Participants will gain an overall understanding of how to approach daylighting design. Topics from this webinar include:
* Definition of successful daylighting
* Components of daylighting design
* Integration with electric lighting
* Top and side lighting strategies
* HVAC savings with daylighting
* Current daylighting software tools
As a result of this webinar, you will be able to:
* Explain how to implement successful daylighting design
* Specify critical daylighting design elements
* Explain how daylighting saves energy and reduces cost
* Describe how to critically analyze design options for projects
* Define one or more performance criteria necessary for successful daylighting
Who should view this webinar? Architects, lighting professionals, interior designers, building design professionals, engineers and anyone interested in learning about daylighting.
Credits: Payment is required to receive credit for this webinar. Once you have completed the course and passed a 10 question quiz, members of the American Institute of Architects (AIA) will earn 1 Learning Unit (HSW). Credit for the AIA Sustainable Design requirement has been submitted for 1 Learning Unit. Credit for the National Council on Qualifications for Lighting Professions (NCQLP) has been submitted for 1 lighting education unit. This course has been approved by the United States Green Building Council (USGBC). The webinar will take approximately 1.5 hours to complete and is an audio-visual presentation.
Cost: This webinar is free. To receive credit, you must pay $49 and pass a 10 question quiz.
Questions? For more information, call Phil Jahnke Sauer at 608.238.8276 x124 or click here to email him.
Register: Click here to register now. Space is limited, so register early.
Daylighting is recognized as best practice in energy codes and industry standards due to its documented positive effects on worker satisfaction and performance and potential to generate substantial energy savings….
Daylighting is recognized as best practice in energy codes and industry standards due to its documented positive effects on worker satisfaction and performance and potential to generate substantial energy savings. Daylighting and daylighting control are now encouraged or required by California’s Title 24 energy code, LEED-NC v.2.2, Northeast Collaborative for High Performance Schools, and ASHRAE Advanced Energy Design Guide for Small Office Buildings. At the time of writing, ASHRAE 90.1-2010 and 189.1 standards are expected to include requirements for daylighting controls.
While the benefits of daylighting and daylighting control are clear, demonstrated savings vary widely based on many factors.
The New Buildings Institute states daylight harvesting systems can generate maximum potential savings of 35-60%. The Lighting Design Lab states lighting energy savings can reach 60-80% in offices, classrooms and gymnasiums. According to the U.S. Department of Energy, daylight-response switching coupled with skylights has demonstrated energy savings in warehouses of 30-70%.
And that’s not counting HVAC impacts.
One of the challenges in estimating typical savings is it’s difficult to compare high-performance daylighting and glazing strategies against standard designs because of the numerous differences between buildings. How do we know realized energy savings are due to the daylighting strategy and not some other factor such as building orientation?
To address this question, the Energy Center of Wisconsin conducted a controlled experiment at the Energy Resource Station near Des Moines, Iowa. Two sets of four identical rooms provided the comparison testbed, with each supplied by independent lighting and HVAC systems. One set of rooms, the Test Rooms, were configured with high-performance glazing and direct/indirect light fixtures with daylighting dimming control. The other set of rooms, the Control Rooms, were configured with standard clear-glass glazing and recessed fluorescent fixtures with no photosensors or dimming control.
This allowed a direct comparison of lighting and HVAC energy consumption during three rounds of study conducted during the summer, fall and winter of 2003—or a total of 70 days of operation—based on three conditions: 1) the base case described above, 2) reduced fenestration (simulated by the use of exterior panels to partially cover the windows), and 3) adding an interior light shelf to enable deeper penetration of daylight into the room interior.
The Energy Center of Wisconsin measured lighting and HVAC energy savings exceeding 20% based on operating costs of abut $1.13/sq.ft.
Lighting energy savings were determined to be about one-third, or 32%, based on $0.15/sq.ft. annual operating costs for the Test Rooms compared to $0.22/sq.ft. for the Control Rooms, resulting in $0.07/sq.ft. savings per year. Cooling energy savings were measured at 25%, fan energy savings at 3%, and savings in demand charges at 24%, while heating energy increased marginally.
The Test Room fixtures frequently operated at some level of reduced output, around 50% on sunny days. Note that the building geometry offered a ratio of 75% perimeter area (friendly to sidelighting) to 25% core areas, so about a quarter of each room’s floor space did not receive daylight or daylighting dimming. (The windows also did not include blinds.)
The biggest operating cost savings, however—about two-thirds—resulted from lower cooling loads. About one-half were related to reduced demand charges. Interestingly, the three Test Room configurations (base case, etc.) showed very little change in lighting or HVAC energy use, although the reduced fenestration option did produce somewhat higher lighting energy consumption because of less daylight.
The researchers concluded: “The data from this experiment demonstrate clear and substantial reductions in lighting and HVAC energy consumption due to the lighting and window specifications.”
The “Energy Savings from Daylighting” report can be downloaded free here.
Interested in new lighting technologies? PIER has published three briefs about emerging technologies that are available for free download. Note: All files download as PDF files. Savings Persist with Monitoring-Based…
Interested in new lighting technologies? PIER has published three briefs about emerging technologies that are available for free download. Note: All files download as PDF files.
Savings Persist with Monitoring-Based Commissioning (TB-39) shows how monitoring-based commissioning (MBCx), a program approach that combines permanent building-energy-system monitoring with standard retrocommissioning practices, can provide substantial, persistent energy savings. A pilot program conducted at 25 California university campuses demonstrated that MBCx has the ability to:
* Reduce peak-period electricity use and total annual energy use;
* Trend and benchmark building-performance data continuously;
* Catch problems with control systems that are normally hard to detect; and
* Identify cost-effective retrofit opportunities.
MBCx can be used in commercial and institutional buildings with energy information or energy-management systems that are capable of trending building energy use.
Daylight Harvesting Made Simple (TB-36): Daylight harvesting systems, which automatically adjust lights in response to the amount of daylight in a space, can provide significant energy and demand savings. However, these systems are usually expensive to install, commission, and maintain and may not perform as well as expected.
This brief explains how researchers at the California Lighting Technology Center at the University of California at Davis developed a new approach called the Simplified Daylight Harvesting system that is easy to install and provides automatic and continuous calibration. The system uses photosensor readings to set lights to on, off, or intermediate levels and gives users the ability to adjust settings. The fixtures can be cost-effectively used in daylit spaces in commercial buildings to produce energy-cost savings and reductions in peak demand charges.
LED Hybrid Porch Light Cuts Energy, Maintenance Costs (TB-37) addresses the problem of wasted energy in keeping outdoor areas, such as porches and walkways, illuminated all night long. A new hybrid lighting design features a low-wattage, high-brightness LED integrated with an occupancy sensor that turns on a CFL or incandescent lamp only when motion is detected—enough to light a path or allow a person to unlock a front door. After a few minutes, the occupancy sensor turns off the CFL or incandescent, while the LED array continues to run. The hybrid porch fixture enhances security while saving energy. The fixture is well-suited for entry and walkway lighting at office buildings, hospitals, apartment complexes, residential housing, universities, hotels and motels.