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

Daylight for the beauty ! • How much daylight (footcandles- lux) • Quality of light (glare and luminance ratios) 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 • SC varies from 0.01 to 15% Fig: Components of the Natural Light

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

Key Architectural Issues The daylight factor in a particular building space depends upon a number of design factors including • • size of daylight apertures (windows, skylights, etc.); • • location of daylight apertures (sidelighting, toplighting, etc.); • • access to daylight (considering the site, building, and room • contexts); • • room geometry (height, width, and depth); • • location of the point of interest relative to apertures; • • visible transmittance (VT) of glazing; • • reflectances of room surfaces and contents; • • reflectances of exterior surfaces affecting daylight entering the aperture; • • the effects of daylighting enhancements (such as light shelves).

The daylight illuminance at any given point in a building depends upon the factors noted above and: • the building’s global location and prevailing climate; • the time of day/month/year; • the current sky conditions. Daylight factor versus illuminance as a measure of daylighting. The illuminance values will change throughout the day, while the daylight factors will be reasonably constant throughout the day (under similar sky conditions). 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: • 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

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

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

Light shelf & ceiling reflectors

Typical lightshelf. Minimum Reflectance Values 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

Rooflights at Crookham Church School. (Architects: Edward Cullinan Architects.) Mt. Airy Public Library 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

Atrium Environmental Systems in Architecture - Daylight- 2nd lecture

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

Celestins Square (The Car Bark) Central Shaft -Germany 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

Representative measured light levels in tall shafts at De Montfort University’s Queens Building. 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

The Heliostat System الهيليوستات نظام للاستفادة القصوى من الضوء الطبيعي قد يكون سلبي أو إيجابي فهو يتكون من مرايا وعدسات تركز الضوء الطبيعي إلى داخل فتحة جهاز النقل. The Heliostat System Environmental Systems in Architecture - Daylight- 2nd lecture

The Heliostat System Environmental Systems in Architecture - Daylight- 2nd lecture

Lighting design In Architecture