TASK LIGHTING

Task lighting reduces the demand on larger lighting sources and focuses light where and when we need it. Fixture type and efficiency is very important depending on the frequency of use. For task lighting used for longer periods of time, fluorescent and LED fixtures are best.

Natural Lighting Techniques

Natural daylight not only reduces demands on artificial lighting sources, but it also improves indoor environmental quality. It's understandable that privacy concerns and room location doesn't always allow direct window access to the outdoors or the ability leave blinds or curtains open. Consider techniques such as obscure glazing, solar light tubes, or light shelves to bring natural light deeper into a space.

Obscure glazing is achieved through the use of windows or glass blocks that allow light to pass through but limit or distort visibility. This works great for spaces where levels of privacy are desired such as bathrooms or basements. Glass blocks, window tinting, and glass "frosting" are available in a wide variety of patterns to achieve different levels of privacy. Windows located above eye level such as transom windows over doors or other windows, are also an option for allowing daylight into a room without sacrificing privacy. Operable transoms can also add cross ventilation to naturally ventilate spaces. Note that glass blocks have very poor thermal performance compared to double-glazed windows.

Solar light tubes are designed as a hollow tube of reflective material that penetrates the roof to transport light into a space. A dome lens on the roof side captures and bends light down the tube and into the space. They are different than skylights in that they are installed to be used as a lighting source rather than a source of supplemental daylight. Condensation and air leakage is much less of an issue as the tubes are often evacuated, meaning air has been drawn out and the tube has been sealed to prevent heat lost through conduction.

Light shelves are both interior and exterior elements installed on windows to project light deeper into a space. Just like it sounds, a horizontal "shelf" with a reflective top surface, is installed above eye level to reflect light. The system works best when you have both an interior and exterior shelf working together. Different light levels will be delivered into the space throughout the day and year depending on the position of the sun in the sky. The light shelf can also help block unwanted light and glare. At certain times of the day, it will shade area below the shelf near the window. Depth of the light shelf is determined by which times of day you are trying to project or block the most light.

More information about natural lighting techniques available at the following locations:
- daylighting
- light shelves