Sustainable Lighting Strategies Cathedral of Christ the Light Specialization in Environmental Architecture 1: Green Design

Energy Use In homes and offices from 20 to 50 percent of total energy consumed is due to lighting. Lighting accounts for 20 percent of all electrical energy usage. Lighting accounts for about five to ten percent of total energy use

Sustainable Lighting The approach to sustainable energy use is a two pronged: Energy Conservation Energy Efficiency It can be described as minimizing energy consumption and carbon emissions while still maintaining suitable illumination on an economically satisfactory basis.

Daylighting

Daylighting In Architecture Is the practice of placing windows or other openings and reflective surfaces so that during the day natural light provides effective internal lighting. Most simply, daylighting is the practice of using natural light to illuminate building spaces. Barcelona Museum of Contemporary Art (Architect: Richard Meier)

Natural Lighting Benefits Reduced energy consumption. Reduction of mildew or mold built-up. Healthy dose of vitamin D. Improved performance due to change in working environment. Increased visual appeal in interiors. Kimball Art Museum The Pantheon

Daylighting Strategies Sidelighting is a daylighting strategy that uses apertures located in the wall planes as the point of admission for ambient daylight. Toplighting is a daylighting strategy that uses apertures located at the roof plane as the point of admission for ambient daylight.

Strategies and Tools Daylighting Windows / Clerestories 3 ways to improve the amount of light available from a window. Place window close to a light colored wall. Slant the sides of window openings so the inner opening is larger than the outer opening. Use a large light colored window sill to project light into the room.

Strategies and Tools Light Shelves Are used to more evenly distribute daylight entering a building through sidelighting apertures 12” minimum width An effective way to enhance the lighting from windows on the equator-facing side of a structure. The light shelf projects beyond the shadow created by the eave and reflects sunlight upward to illuminate the ceiling.

Strategies and Tools Skylight Reichstag Skylight is any horizontal window, roof lantern or oculus, placed at the roof of the building, often used for daylighting. The optimal area of skylights varies according to climate, latitude, and the characteristics of the skylight. It is usually 4-8% of floor area. Spacing of skylights are usually equal to the ceiling height.

Strategies and Tools Light Tube Also called a solar tube, solar pipes, light pipes. A devices consisting of a lens that is installed on the roof, an adjustable mirror-lined tube (10- 20” diameter) It is placed into a roof and admits light to a focused area of the interior.

Strategies and Tools The Thinner the Building, the Better. Maximize ceiling and window height to gain better light distribution Separate Daylighting and View Windows. Bring Daylight in from above to obtain deeper penetration into space.

Strategies and Tools Maximize North and South Faces Minimize East and West Faces A southern facing orientation is optimal if a building or system is located in the northern hemisphere, and a northern facing orientation is optimal if located in the southern hemisphere.

Strategies and Tools Reduce the surface area of Glass Too much glass could end up with heat-gain and heat-loss problems, and glare issues. Filter and shade daylight to avoid direct sun and sky light

Strategies and Tools Open up the Plan Limit Private Rooms / Spaces

Strategies and Tools Pick Light Colors with High Reflectance Coefficient Bounce daylight off surrounding surfaces to diffuse light in more even patterns

Artificial Lighting

Assessing a Sustainable Lighting Program 1. Lighting Technology Lamps Fittings and Luminaires Fluorescent Tube LED Lamp Compact Fluorescent Lamp

Assessing a Sustainable Lighting Program 2. Lighting Design Colors of Wall and Ceiling Lighting Layout Lighting Control

Efficient Lighting Design Approaches Avoiding incandescent lights, using CFLs or light-emitting diode. The color of the walls, ceilings and furnishings should be kept light so that it reflects more light to the workspace areas. Reducing the general illumination level by employing task lighting. Using dimming or step ballasts for energy savings when full light level is not required. Matching the amount and quality of light to the function to be performed. Switching lighting for perimeter zones to be separate from interior zones. Energy consumption can also be reduced through sophisticated lighting control systems. Specifying higher efficiency light sources to produce more light with lower energy consumption. Consider solar powered lighting.

Assessing a Sustainable Lighting Program 3. Practices: Organizational Behavior It is essential to engage with and educate users on the need for the change and the benefits of sustainable lighting systems. Educating and training of users to gain commitment to the lighting project. Automatic shutdown of lights after 6 or 7 pm, beyond which local task lights can be used. Negotiating cleaning contracts for day time, so that all lights can be switched off after office hours. Reinvigorating any existing campaigns supporting good practices in lighting. Integrating sustainable lighting strategies into the company’s procurement policies and practices. Switching to green power to meet an organization’s energy needs. Offsetting lowered emissions through carbon credits and other alternative arrangements.

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