Joint CNC/CIE – IESBC Workshop - Canadian Research and Development Activities in Light and Lighting

Thursday, October 14, 2010

Vancouver, B.C.


The Influence of Color Interreflections on Lighting Simulations

Ian Ashdown, P. Eng., FIES
President, byHeart Consultants Limited

Most lighting simulation programs represent color as RGB triplets in a device-dependent color space such as ITU-R BT.709. Implicit in this representation is the assumption that interreflections between colored surfaces can be accurately calculated using three separate color bands. We demonstrate that while this assumption generally holds for most architectural finishes, it can result in substantial prediction errors for saturated colors.

Lighting for Net-zero Ready Schools

Jim Love, D. Arch., P. Eng., MRAIC, LC, LEED AP
Professor, Faculty of Environmental Design
Adjunct Prof., Dept. of Mechanical Engineering
Chair in Sustainable Building Technologies
University of Calgary

The goal of green building is to improve the indoor environment for occupants while reducing negative effects of building construction and operation on the global environment. The University of Calgary has been engaged in action research on “low carbon” schools, working with design teams and conducting post-occupancy assessment of system performance.

Natural Resources Canada (NRCan's) considers buildings that have achieved a reduction of more than 70% relative to Canada’s Model National Energy Code for Buildings to be "netzero ready" (in netzero buildings, annual energy production equals annual energy use). Of about 250 buildings reviewed under NRCan's design validation program only 2 have achieved this. Only the Lawrence Grassi Middle School (Canmore, Alberta) has achieved this without a renewable energy system. The environmental control systems design and research leading to this will be discussed, considering the role of lighting.

Lighting Requirements in the NECB 2011

Dr.-Ing. habil. Alexander Rosemann, P.Eng., LC, CEM
Specialist Engineer - Codes & Standards
Innovation & Conservation Leadership
BC Hydro, PowerSmart 

The National Energy Code for Buildings (NECB) will be published in 2011. The lighting requirements differ substantially from the last version, the Model National Energy Code of Canada for Buildings (MNECB) published in 1997. The talk outlines the requirements of the prescriptive and trade-off compliance paths in Part 4 - Lighting. The methodology for the new trade-off path is based on the German standard DIN 18599-4. The model uses the installed lighting power density, the area of the daylit and non-daylit section and the effective operational times during daytime and night-time for each building zone. Models like these face the challenge that they base their assumptions on the data provided by early design stages of a particular building. The estimate needs to be reasonably precise to enable a reliable comparison between a set of options. At the same time, the amount of input data should be minimized to allow for a good and easy usability.

Adaptive Street Lighting 

Dr. Cristian Suvagau, P.Eng., LC, CEM
BC Hydro, Power Smart ENGINEERING

Adaptive street lighting can be defined as outdoor lighting that varies light level automatically and precisely in response to changes such as the level of use or occupancy of an outdoor location. This talk will address the concept and the potential barriers to implementation as well as the principal existing technologies and case studies. Deploying an adaptive lighting system requires a systematic approach in order to maintain safe lighting levels and achieve maximum energy savings benefits. The talk is also introducing a recent incentive program developed by BC Hydro.

Solid State Lighting for Offices: Let's Get it Right

Jennifer A. Veitch, Ph.D.
NRC Institute for Research in Construction

Millions of square metres of office space are lit with linear fluorescent lamps. For solid-state lighting to make a major dent in the lighting energy budget will require light sources and luminaires that are more efficacious than the existing technology, and a reason for building owners and tenants to change to an initially expensive, new and unfamiliar technology. Uptake of this new technology will require that consumers trust that it is safe and effective as well as energy-efficient. Thus, we need to develop new luminaire designs and operation modes using the unique characteristics of SSL; to integrate SSL with intelligent controls; to identify usability issues and to solve them; and, to develop solid-state lighting systems that deliver a clear advantage over the fluorescent systems they are intended to replace. This presentation will summarize NRC-IRC activities in this area, including ideas for SSL systems that might offer "something more" that will encourage their adoption.

Quantum Dots and the Future of LEDs

Venkat Venkataramanan, Ph.D.
Institute for Optical Sciences
University of Toronto 

Solid state lighting (SSL) is now an energy efficient and cost-competitive alternative to conventional lighting. This talk will review the current status, progress and challenges in SSL for general-purpose illumination. One of the crucial issues that is holding back the widespread adaptation of LEDs is its poor color quality. Almost all commercially available white LEDs use GaN blue emitters combined with inorganic yellow phosphors. This results in cool white light and is poor in rendering colours. Quantum dots have high colour tunability, narrow emission and high luminescence efficiency and are emerging as viable alternatives to inorganic phosphors. This talk will also review the progress in quantum dot phosphors SSL applications. 

Implications of Core Sunlighting for Energy-Efficient Buildings

Lorne Whitehead, Ph.D.
University of British Columbia

When daylight enters a building there is an opportunity to turn off the electric lights that would otherwise provide illumination. This can be true with conventional daylighting, which typically works only in the peripheral regions of a building, and also for core daylighting systems that direct concentrated sunlight into the core regions. However, providing daylight does not automatically guarantee good lighting, reduced energy consumption, or an economically viable return on investment. In green construction, daylighting is often assumed to give these benefits, but the required increased fenestration introduces glare, energy losses and extra costs that often are not fully taken into account. This presentation will discuss these issues for both types of daylighting systems. An optimal solution may be a combination of the two approaches that provides better lighting, uses less energy, and reduces operating costs enough to justify the required investment. 

Whiteness assessment of papers – impact of LED illumination

Joanne Zwinkels, Ph.D.
Principal Research Officer
Institute for National Measurement Standards
National Research Council of Canada 

White LED sources have been developed as replacements for various indoor lighting systems. The impact of this LED illumination has been generally considered in terms of its colour rendering index which is calculated from its spectral power distribution (SPD) over the visible spectrum only. However, for certain applications, such as the whiteness assessment of papers, this performance metric is insufficient. To improve the appearance and commercial value of white paper, papermakers often use fluorescent whitening agents (FWAs) which absorb in the UV and emit in the blue, giving an increase in the total light reflected from the paper. The shape and the intensity of this added fluorescent light depend critically on the SPD of the irradiating source in both the UV and visible wavelength regions. 

This paper discusses the impact of these white LED sources for whiteness assessment by comparing the calculated total reflectance due to interaction of their SPDs with a representative fluorescent white paper sample. As expected, their relative deficiency in UV energy for activating the FWA, gives whiteness values that are significantly lower than those found with incandescent lamps. In light of these results, the paper industry may want to re-consider their approach of adding FWAs to enhance the assessment of paper whiteness.