Environmental Controls Lecture 15 Design Control Daylighting Overview Daylighting Strategies Daylighting Design Light Flow The Flow of Daylight Source - Path - Target 1
The Flow of Daylight The Flow of Daylight BRIGHTNESS CONTROLS Light Level Measurements Sky conditions Vertical/horizontal orientation Solar altitude Solar bearing Season S: F.12.3 p. 528 Sky Light Level Measurements Sky light levels S: F.12.6 p. 531 2
Sky Luminance Light from the sky Zenith Luminance (L z ) Horizon Luminance (L h ) Light from surface Illuminance (E) CIE: Commission Internationale de l Eclairage S: F.12.2 p. 527 Sunlit Elevations 10-15% of light Shaded Elevations 50 +/- % of light Secondary Sources Ground/Roof Plane Carmel, CA Taliesin West, AZ San Diego, CA Secondary Sources External Reflections Proximity Materiality Orientation San Francisco, CA Denver, CO 3
Brightness Controls Shading Devices Ornamental Elements Architectural Form Landscaping Salt Lake City, UT River Forest, IL Wellesley, MA San Francisco, CA Glazing Admittance Functions Visible Light Transmission (VLT) Spectrally Selective Coatings Diffusion & Translucency Framing Effects Chicago, IL Los Angeles, CA South Window Orientation Preferred for year-round light and warmth North Most uniform light East/West Most difficult glare control Most difficult to control heat gain Most variable light City Hall, Tempe, AZ Tilted Redirect veiling reflections 4
Internal Reflections Texture Matte Specular Surface Orientation Color Glencoe, IL Westbury, CT Los Angeles, CA Daylighting Overview Building Form Preindustrial buildings daylight for primary illumination high ceilings tall openings Greek House, Priene, Greece 5
Pantheon, Rome Church of S. Marco, Venice, 978 AD Building Form Architectural tectonics illumination ceremony/symbolism space definition Notre Dame de Chartres, 1260 AD St. Peter s, Rome, 1614 AD Building Form Industrial era commercial buildings significant daylight for illumination high ceilings tall openings vertical aspect Seattle, WA Cleveland, OH Building Form Industrial era manufacturing buildings daylight for illumination high ceilings tall openings on sides clerestories on roof horizontal aspect College Station, TX Warren, MI 6
Building Form Chicago, IL Modern buildings electric lighting for primary illumination daylight=glare reduced ceiling heights Salt Lake City, UT New York, NY Daylighting Strategies Daylighting Approaches Sidelighting: Light enters through the side walls Toplighting: Light enters from the roof 7
Daylighting Apertures Fenestration provides: Admission for control and distribution of daylight Ventilation and energy conservation A distant focus point Open areas Emergency exits Apertures provide: Connection to nature Architectural design opportunities Free lighting Tacoma, WA Application Guidelines Offices/Educational Facilities: Minimize direct glare Minimize reflected glare Eye level window area of low transmittance glazing to allow outward vision Control brightness high sidelighting or toplighting Industrial Facilities: Minimize direct glare Minimize reflected glare Provide uniform lighting on work area Control brightness toplighting Brightness Controls Overhangs Vertical Elements Louvers Shades/Drapes Landscaping Exterior Reflectors Interior Reflectors 8
Rule of Thumb Vertical Work Surface: Sidelighting Horizontal Work Surface: Toplighting Unilateral: light from one side only Sidelighting Bilateral: light from two sides Note: overhang(s) could be louvered Sidelighting 2.5 H H= height of top of window H Width of room=2.5h 9
Lightshelves Sidelighting Sidelighting Adapting Lightshelves to Climate Sidelighting Reducing subjective brightness 10
Sidelighting Light collectors redirect light Sidelighting Sun Catchers Orientation dictates form Use integral brightness control Toplighting Skylights Dome is better than flat Use integral brightness control Seal against moisture Operable? May be used with light wells or louvers 11
Toplighting Roof Elements Orient to desired light Use brightness control Seal against moisture Operable? May be used with light wells and louvers Clerestory Monitor Sawtooth Toplighting Light Ducts 1. Plain duct 2. High reflectance coating 3. Fiber optics 1. 2. 3. Toplighting Atrium & Arcades One or more floors Use brightness control Seal against moisture May be used with monitors, sawtooth clerestories, louvers, lightwells and sun catchers Ann Arbor, MI 12
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