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

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

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

Physics of light: • Light: is an energy carried by Elctro-magnetic waves having a certain range of frequency that are felt by the eye rentina and the brain causing the sensation of light. Wavelength is visible to the human eye from 400-700nm

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

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 requirements: • زاوية العائق: 70≥θ • معامل البروز: projection factor PF • مساحة النافذة بالنسبة إلى مساحة الحائط الخارجي الموجودة به: WWR ≤10% للفراغات الخدمية و15% للفراغات المعيشية. • معامل نفاذية الزجاج للفتحةVLT = 0.45 • نهو الأسطح الداخلية (الأسقف- حوائط- أرضيات): فاتح للخدمية وفاتح إلى متوسط للمعيشة 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

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 -court 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

Design Consideration • Environmental factors: • solar heat: increases the rate of heat gain or loss of the building fabric. • Noise. So, • The proper choice of window orientation and suitable sun shading device or constructions, the solar heat gain can be greatly reduced. • The use of double glazed window units is able to cope with the noise problem and reduce significantly the heat gain or loss through the window. Environmental Systems in Architecture - Daylight- 2nd lecture

Design Consideration • the DF and consequently the illumination near the window decreases as the height of the window above the floor is increased Environmental Systems in Architecture - Daylight- 2nd lecture

2. Obstructions: • Any obstruction (buildings opposite the window, trees, etc.) decreases the illuminance in rooms. • Obstructions which subtend elevation angles of more than 25-30o significantly reduce the daylight penetration. • 3. Fenestration: • The lighting conditions in a room depend primarily on the fenestration. Environmental Systems in Architecture - Daylight- 2nd lecture

Artificial light & Daylight factor • The required quantity of artificial light input is to achieve an illumance at the rear of the room comparable to, but slightly less than, the daylight illuminance near the window. For example: Environmental Systems in Architecture - Daylight- 2nd lecture

Innovated Daylighting Systems • Light Pipes: • The system consists of: • COLLECTOR /CONCENTRATOR • TRANSPORT SYSTEM • EMITTER The Light Pipe Principle Environmental Systems in Architecture - Daylight- 2nd lecture

Light Pipes… Environmental Systems in Architecture - Daylight- 2nd lecture

فراغ معيشة قبل وبعد استخدام أنابيب الإضاءة Environmental Systems in Architecture - Daylight- 2nd lecture

London Art museum Environmental Systems in Architecture - Daylight- 2nd lecture

Polla museum in Japan Environmental Systems in Architecture - Daylight- 2nd lecture

Lighting design In Architecture