April 27, 2007

Innovation

Software models daylight, indoor air pollutants

New technology releases designed to enhance work

PETER KENTER

correspondent

The National Research Council (NRC) is promoting two electronic tools — Daylight 1-2-3 and IA-QUEST — developed to assist design practitioners in creating buildings that are comfortable, suitable for the Canadian climate and environment-friendly.

“Over the past three or four years, NRC has increased its efforts to translate scientific and technical knowledge into integrated solutions to help resolve ongoing problems in construction and property management,” says Morad Atif, director of Indoor Environment Programs with NRC.

Daylight 1-2-3, released in March, is designed to help architects, designers and engineers with no previous experience in computer simulation to develop climate-responsive, energy-efficient daylighting designs.

The software tool was created in collaboration with Natural Resources Canada and builds on the earlier success of NRC’s DAYSIM, an advanced daylighting analysis tool currently used in 94 countries.

NATIONAL RESEARCH COUNCIL

A National Research Council staff member tests IA-Quest VOC modeling software.

“The industry was asking us to create a realistic prediction of daylight penetration and calculate its effect on energy savings,” says Atif.

“They wanted to know how the light falls, and the contours of the daylight within the space in as simple and reliable a way as possible.”

When data, such as geographical location, building orientation, and window size and location are entered into the program, it creates a prediction of daylight autonomy; the percentage of occupied hours of the year when there is sufficient daylight for an occupant to work without the need for artificial lighting.

“The new software includes climatological data for Canada and the U.S. and also takes into account the ‘shading behaviour’ of the occupants — how they react to sunlight with blinds, curtains or skylight controls,” says Atif.

Effective daylighting is difficult to design, says Dr. Christoph Reinhart, associate research officer with the NRC Lighting Group.

“Visual quality and energy savings should both be considered when designing for daylight.”

An NRC survey of nearly 200 design practitioners indicates that daylighting decisions are most often based on an architect or designer’s experience from previous work and a few simple rules.

In contrast, Daylight 1-2-3 allows users to assess and quantify each building’s particular lighting situation.

“It gives immediate feedback at the design stage,” says Dr. Reinhart. “It allows them to develop a feeling of how large a window should be for lighting while keeping cooling loads in check. The software considers a variety of common glazing types as well as building orientations.”

A second NRC software tool, IA-QUEST, models the release of various volatile organic compounds (VOCs) from a range of building materials and predicts their effect on indoor air quality. The software was released about a year ago and is now being used and assessed in almost 40 countries. Software users input data such as room dimensions and ventilation rates, then select materials such as paint, carpet and furnishings.

The software then runs an air quality simulation that projects results for a few hours, or months into the future, providing a profile of the total VOCs in the room over time.

But, while some VOCs are hazardous to health, others are not. An evolving list of approximately 90 “VOCs of Concern” is developed in conjunction with Health Canada to clarify health effects. The software also provides links to various standards, such as LEED, to provide a regulatory context for the information.

“In the first year, we’ve been concentrating on user reactions to the software,” says Atif. “Now we’re working to update the list of VOCs.”

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