Lighting design In Architecture

1. Lighting design In Architecture Natural illumination & Artificial lighting Environmental Systems in Architecture 1st lecture .. Eng. Nagham Ali Hasan

2. 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

3. Properties of light: • Intensity (brightness) • Frequency (wave length) • Polarization (Direction of wave fluctuation) Speed of light: 299792.458 m/s ≈ 3*106 m/s The speed of light depends on the medium in which it is travelling.

4. Lighting Resources: Natural Illumination Artificial Lighting daylight for interior spaces “Light from the sun” Such as : lamps “electric light- gas- oil lamps”

5. Artificial Lighting

6. Lamps:

9. Artificial Lighting Forms of lighting for internal areas

10. Artificial Lighting Forms of lighting for internal areas Semi Direct light : 1- is preferred for all general illumination of work rooms, meeting room, rooms in public use and circulation zones An angle of illumination between 70-90 2- can provide uniform wall illumination.

11. Directional Effect Forms of lighting for internal areas Some directional effects of light make it easier to recognize the details of a task; others make recognition more difficult.

12. Defused lighting Effect

13. INDirect/ DIRECT LIGHTING Effect

14. INDirect LIGHTING Effect It can give an impression of a bright room free of glare even at high a law lighting level. FL are used in indirect/direct lighting, but they may also be combined with filament lamps. Height of room h~3m

15. Glare : • Glare is the discomfort or impairment of vision experienced when parts of the visual field are excessively bright in relation to the general surroundings. • Glare depends on the Reflectance. • Glare (m.lembert)= Illumination Intensity * Reflectance

16. Control of Glare Glare is controlled by the following means: to limit the luminance of the lighting sources in the direction of the eye, e.g. replacing bright source with a number of weak sources, to screen the light sources from the view, e.g. introducing downstand screens or light-diffusing fittings to the luminaires, to reposition the work station, to use working surfaces, paper, office machines etc. that have matt surface, to raise the background luminance against which the luminance sources are seen, to construct external obstructions or low transmittance glass to limit daylight penetration, and to construct windows on adjacent or opposite walls to reduce contrast.

18. Somedefinitions… • The luminance (Luminous Intensity) (I)…Unit: Candela: measure of intensity of light source in a given direction • The Luminous Flux (Φ)…Unit: Lumen: is amount of light energy radiated per second from a source of light. • i.e: The Luminous Flux (Φ)= 4π*L • The Illuminance: (E) …Unit: Lux: measure of light incident on the surface =Luminous Flux / area of the sphere surface = L/ r2 = lumen/ m2 lying at distance” r” from a source of light

19. Somedefinitions… 􀂄 􀂄 Candela (cd): measure of intensity of light source in a given direction 􀂄 Lumen (lm): total amount of light emanating from a light source 􀂄 Footcandles (fc): indicates the density of light landing on a surface = lumens per sq.ft.

20. Quantities and units

22. :Florescent lamps Correct use of Florescent lamps

24. Open Loop – monitors the available daylight level at the daylight aperture (window, skylight, clerestory, etc.) and adjusts electric lighting levels as appropriate

25. Lighting Controls Necessary to realize significant energy savings –both peak demand (kW) and energy use (kWh) Closed Loop – monitors total light level in the space provided by both daylight and electric light (usually light level at work surface such as desk or table) and adjusts electric light as appropriate

26. thank you