Lighting design In Architecture

“DAYLIGHT” Lighting design In Architecture Instructor: M Sc. Eng. Nagham Ali Hasan 2nd lecture- 2nd semester 2008/2009

DAYLIGHT: • Importance Of The Daylight • Daylight Sources • Daylight Components • Daylight Strategies • Daylight Calculations Environmental Systems in Architecture - Daylight- 2nd lecture

Sunlight and Daylight Daylight architecture: large, tall windows. Sunlight architecture: small, low windows reflective outer walls . Environmental Systems in Architecture - Daylight- 2nd lecture

Three Components of DaylightingDesign 􀂄 Aesthetics (light and shadow, color, view…) 􀂄 Human performance (psychology and biology benefits) 􀂄 Energy (sustainable design) Environmental Systems in Architecture - Daylight- 2nd lecture

Daylight for the beauty ! • How much daylight (footcandles- lux) • Quality of light (glare and luminance ratios) Environmental Systems in Architecture - Daylight- 2nd lecture

Daylighting for Human Performance 􀂄 View 􀂄 Visual comfort 􀂄 Performance –economic, increased sales, improved test scores, etc….. Environmental Systems in Architecture - Daylight- 2nd lecture

Daylighting to Save Energy 􀂄 kW (peak demand) 􀂄 kWh 􀂄 Set performance goals 􀂄 Lighting Power Density Environmental Systems in Architecture - Daylight- 2nd lecture

What is successful daylightingdesign? • Use of diffuse light from the sky • Daylight as primary source of illumination • Quality visual environment • Integration with electric lighting system • Appropriate control of natural light • Energy savings Environmental Systems in Architecture - Daylight- 2nd lecture

Light Source…. Environmental Systems in Architecture - Daylight- 2nd lecture

Sky conditions: Cloudysky: Sky having more than 70% cloud cover. Clear sky : Sky that is less than 30% cloud cover. Overcast sky: Sky completely covered by clouds, no sun visible Environmental Systems in Architecture - Daylight- 2nd lecture

Typical illuminances E and luminances under daylight and electric light. Environmental Systems in Architecture - Daylight- 2nd lecture

Components of the Natural Light : • There are three separate components of the natural light that reaches any point inside a building: • Sky Component (SC)- Directly from the sky, through an opening such as a window. • Sky Component (SC) depends on: • Width of the window • Distance between the point and window Fig: Components of the Natural Light • SC varies from 0.01 to 15%

Externally Reflected Component (ERC)- Reflected off the ground, trees or other buildings. Externally Reflected Component (ERC) is small. The luminance of obstrction is taken as 10-20% that of the sky • Internally Reflected Component (IRC) - The inter-reflection of 1 and 2 off surfaces within the room. Internally Reflected Component (IRC): is a half of SC and is therefore significant Environmental Systems in Architecture - Daylight- 2nd lecture

Daylight Component… • Daylight factor defined as: The ratio of daylighting illumination on a horizontal point indoors to the horizontal illumination outdoors, expressed as a percentage. For cloudy sky For clear sky Environmental Systems in Architecture - Daylight- 2nd lecture

Daylight Factor The daylight factor is defined as : where Ei = illumiance due to daylight at a point on the indoors working plane Eo = simultaneous outdoor illuminance on a horizontal plane from an unobstructed hemisphere of overcast sky

Daylight factor • Calculated daylighting design is essential in: • balancing heat gain and loss, • controlling glare, • cutting energy costs and • creating a comfortable environment within any building Environmental Systems in Architecture - Daylight- 2nd lecture

Design daylighting… • Factors affect on lighting design for interior spaces: • Building location and orientation • Function of the space • Space depth • Openings size and place • Glazing • Walls finishing ”reflectance” Environmental Systems in Architecture - Daylight- 2nd lecture

Daylight systems: • How redirect the daylight into spaces?? • Windows • Saw-tooth • Monitors • Skylight • Atrium Environmental Systems in Architecture - Daylight- 2nd lecture

Vertical windows: • Light level falls off quite quickly as you move deeper into the space. • Useful daylighting will only reach a distance of 2.5 times the height of the top of the window above the work plane (usually taken at a desk height of 60 cm • In a standard office building with a window height of 2.5 m, this means a maximum of about 5-7 metres. Cross section showing lighting distribution from a single-sided window installation Environmental Systems in Architecture - Daylight- 2nd lecture

Windows… The Effect of Windows on Two Sides of a Room on DF Environmental Systems in Architecture - Daylight- 2nd lecture

Environmental Systems in Architecture - Daylight- 2nd lecture

In overcast sky condition: Long thin horizontal windows will not prvide as much light per unit area as taller more vertical windows The Effect of Window Height on DF Environmental Systems in Architecture - Daylight- 2nd lecture

Fig. shows how the DF varies across a room using two types of windows, both having the some total area: • (a) is for three tall windows, and • (b) is for one long, high-level window. • Window (a) will give a good open view, but (b) will provide more even daylight illumination. The Effect of Window Shape on DF Environmental Systems in Architecture - Daylight- 2nd lecture

Cross section showing how illumination vectors become more horizontal as sidelight travels deeper into a space Environmental Systems in Architecture - Daylight- 2nd lecture

Skylight : Double-glazed units and arange of louvered systemsshould be used wherever possible to reduce conducted heat losses. Appropriate no. of units is 5% of ceiling area Environmental Systems in Architecture - Daylight- 2nd lecture

English court Environmental Systems in Architecture - Daylight- 2nd lecture

Roof Monitor • Saw-tooth skylight Environmental Systems in Architecture - Daylight- 2nd lecture

Saw-tooth • Saw-tooth inclination • Saw-tooth orientation Environmental Systems in Architecture - Daylight- 2nd lecture

Saw-tooth • Saw-tooth reflectors • Saw-tooth preferred dimension Environmental Systems in Architecture - Daylight- 2nd lecture

Mt. Airy Public Library Environmental Systems in Architecture - Daylight- 2nd lecture

Atrium Environmental Systems in Architecture - Daylight- 2nd lecture

Mashroom column. Frank loyd Write Environmental Systems in Architecture - Daylight- 2nd lecture

Atrium Environmental Systems in Architecture - Daylight- 2nd lecture

Celestins Square (The Car Bark) Central Shaft -Germany Environmental Systems in Architecture - Daylight- 2nd lecture

Kimbel Art Museum - Louis Kahn Use light reflectors under the light system to defuse the light through the internal space Environmental Systems in Architecture - Daylight- 2nd lecture

REDIRECT THE DAYLIGHT: • Light shelf Environmental Systems in Architecture - Daylight- 2nd lecture

Light shelf & ceiling reflectors Environmental Systems in Architecture - Daylight- 2nd lecture

Reflectors & ceiling reflectors Environmental Systems in Architecture - Daylight- 2nd lecture

Interior Finishes - Reflectance Minimum Reflectance Values Environmental Systems in Architecture - Daylight- 2nd lecture

Lighting design In Architecture