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University of Palestine College of Applied Engineering & Urban Planning Department of Architecture, Interior Design & Planning Lighting design In Architecture “DAYLIGHT” Instructor: M Sc. Eng. Nagham Ali Hasan 2nd lecture- 2nd semester /2009

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

Three Components of Daylighting Design
􀂄 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: Clear sky : Sky that is less than 30% cloud cover.
Overcast sky: Sky completely covered by clouds, no sun visible Cloudy sky: Sky having more than 70% cloud cover. 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: Windows Saw-tooth Monitors Skylight Atrium
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

(a) is for three tall windows, and
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

Environmental Systems in Architecture - Daylight- 2nd lecture

Light shelf & ceiling reflectors

Minimum Reflectance Values
Typical lightshelf. Minimum Reflectance Values Environmental Systems in Architecture - Daylight- 2nd lecture

Environmental Systems in Architecture - Daylight- 2nd lecture

Skylight : Double-glazed units and a range of louvered systems should 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

Environmental Systems in Architecture - Daylight- 2nd lecture

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 Rooflights at Crookham Church
School. (Architects: Edward Cullinan Architects.) Mt. Airy Public Library Environmental Systems in Architecture - Daylight- 2nd lecture

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

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

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: Artificial light (lux) Daylight factor 250 0.5% 500 1.0% 750 1.5% 1,000 2.0% 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

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

Environmental Systems in Architecture - Daylight- 2nd lecture

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

Environmental Systems in Architecture - Daylight- 2nd lecture

Environmental Systems in Architecture - Daylight- 2nd lecture

Environmental Systems in Architecture - Daylight- 2nd lecture

مركز تجاري - برلين المانيا
استخدم ثلاث أجهزة هيليوستات 2x2 متر مواجهة للشمس مع استخدام مرايا بدرجة انعكاسية أعلى السقف الزجاجي فوق الفناء الداخلي كوسيلة لإضاءة الفراغ وذلك بنقل الضوء الطبيعي إلى قاعة الاستقبال. مركز تجاري - برلين المانيا Environmental Systems in Architecture - Daylight- 2nd lecture

(movable-orientable Glass Louvres)
5- (movable-orientable Glass Louvres) Environmental Systems in Architecture - Daylight- 2nd lecture

The Glass Louvers may be installed as a movable or fix system
Environmental Systems in Architecture - Daylight- 2nd lecture

Daylighting calculations
Where, T is the diffuse light transmittance of the glazing including the effects of dirt, blinds, obstructions and coverings; Aw is the window area (m2); θ: is the vertical angle subtended at the centre of the window by unobstructed sky; A is the total area of indoor surfaces (ceiling, walls and floor, including glazing); R is the area-weighted average reflectance of ceilings, walls and windows. Environmental Systems in Architecture - Daylight- 2nd lecture

Example:Daylighting calculations
An office room with 4*3m , height 2.5m assume that T = 0.75 and Reflectance of the ceiling= 0.7 Reflectance of the wall= 0.5 Reflectance of the window= 0.1 Reflectance of the floor= 0.3 Environmental Systems in Architecture - Daylight- 2nd lecture

The total area of the room is 59 m2
The total area of the room is 59 m2. The average reflectance is area weighted in the following way: (R side wall) × (Area side wall) = (0.5)(3)(2.5) = 3.75 (R back wall) × (Area back wall) = (0.5)(4)(2.5) = 5.00 (R front wall) × (Area front wall) = (0.5)(10 − 2.25) = 3.88 (R window) × (Area window) = (0.1)(2.25) = 0.23 (R ceiling) × (Area ceiling) = (0.7)(4)(3) = 8.4 (R floor) × (Area floor) = (0.3)(4)(3) = 3.6 —————— Total = 28.61 Environmental Systems in Architecture - Daylight- 2nd lecture

Indicative daylight factors
. Environmental Systems in Architecture - Daylight- 2nd lecture