1. Environmental Controls I/IG Lecture 18 Daylighting Design & Analysis Design Strategies Glazing and Reflectors Sidelighting Analysis Method Lecture 18 Daylighting Design & Analysis Design Strategies Glazing and Reflectors Sidelighting Analysis Method

2. Daylighting Design & Analysis

3. Orientation and Slope Vertical vs. Horizontal Time of year Sun position DL-5 F. 10-1 p. 79

4. Daylighting Components SC=Sun + Sky IRC 1 IRC2 ERC S: F.14.18 p. 590

5. Daylighting Factor (DF) The quantity of interior illuminance on a horizontal work plane expressed as a percentage of illuminance of an exterior unobstructed horizontal plane DF (%) = (E INT /E EXT ) x 100

6. Daylighting Factor (DF) If E INT is 20 foot-candles and E EXT is 1000 foot-candles, then what is the daylighting factor? DF(%)= (E INT /E EXT ) x 100 DF (%)=(20/1000) x 100 DF (%)=2.0%

7. Isolux Contours Lines of similar lighting levels Expressed as DF Darwin College Library, Cambridge, England

8. Isolux Contours Example E EXT = 2000 fc 1: 20 fc 2: 60 fc 3: 100 fc 4: 40 fc 5: 80 fc 6: 140 fc 7: 20 fc 8: 60 fc 9: 100 fc 1+ 2+ 3+ 4+ 5+ 6+ 7+ 8+ 9+ DF(%)= (E INT /E EXT ) x 100

9. Isolux Contours Example E EXT = 2000 fc 1: 20 fcDF=1 % 2: 60 fcDF=3 % 3: 100 fcDF=5 % 4: 40 fcDF=2 % 5: 80 fcDF=4 % 6: 140 fcDF=7 % 7: 20 fcDF=1 % 8: 60 fcDF=3 % 9: 100 fcDF=5 % 1+ 2+ 3+ 4+ 5+ 6+ 7+ 8+ 9+

10. Isolux Contours Example E EXT = 2000 fc 1: 20 fcDF=1 % 2: 60 fcDF=3 % 3: 100 fcDF=5 % 4: 40 fcDF=2 % 5: 80 fcDF=4 % 6: 140 fcDF=7 % 7: 20 fcDF=1 % 8: 60 fcDF=3 % 9: 100 fcDF=5 % 1 3 5 2 4 7 1 3 5 6 4 2

11. Isolux Contours Lines of similar lighting levels Expressed as DF Darwin College Library, Cambridge, England

12. Illumination Gradient An illumination gradient through a section Ludwig Museum, Koln, Germany

13. Design Strategies

14. Selection Parameters Daylight availability Task orientation Space orientation

15. Daylighting Graphs 10’ Ceiling 30” Work plane DL-5: F10-2 p. 80

16. South Facing Walls Solid Overhang a: translucent glazing b: horizontal overhang c: 30º sloped clear glazing d: 45º sloped clear glazing DL-5: F10-5 p. 82

17. South Facing Walls Diffusing Awnings a: translucent glazing b: translucent awning clear glazing c: white vertical slatted awning, clear glazing d: white, horizontal slatted awning, clear glazing DL-5: F10-6 p. 82

18. Light Shelves W: With light shelf WO: Without light shelf DL-5: F10-18 p. 89

19. Skylights Effect of skylight above roof a: flat horizontal b: half-round barrel, white opaque ends c: steeply sloped A-frame, white opaque ends DL-5: F10-21 p. 91Typographic Error In Reading 

20. Roof Monitors North-South Monitors a: translucent panel b: north monitor, clear glazing c: south monitor, translucent glazing DL-5: F10-30 p. 95

21. Roof Monitors Sun Control Baffles/Louvers Light Wells DL-5: F10-35 p. 97

22. Roof Monitors Graphic Design Approach DL-5: F10-37 p. 98

23. Glazing & Reflectors

24. Fenestration Window or Fenestration?

25. Clear Glazing Maximum VLT DL-5: F11-1 p. 105

26. Gray/Bronze Glazing Gray glass preferred where color rendition is important DL-5: F11-2 p. 106

27. Heat Absorbing Glazing Green is more common Blue is becoming more available DL-5: F11-3 p. 107

28. Solar IR Reflective Film Low-E Glass DL-5: F 11-6 p. 109

29. Multiple Glazing Combinations of individual paned glazing Mylar/Film layer Inert gas (argon or krypton) “Superwindow”

30. Exotics LED Windows Aerogels Kalwall Prototype House and Studio Thomas Herzog

31. Sidelighting Method

32. Subscripts w=window k=sky g=ground u=sun

33. Parameters RgRg TgTg

34. Illumination (E) E kw Illumination from sky on window E kg Illumination from sky on ground E uw Illumination from sun on window E ug Illumination from sun on ground E kuw Illumination from sky and sun on window E kug Illumination from sky and sun on ground

35. Illumination (E) E gw Illumination from ground on window E kwp Illumination from sky (and sun) on work plane E gwp Illumination from ground on work plane R g Reflectance of ground surface A g Window area of transmittance T g Transmittance of glass

36. Coefficients of Utilization (C,K) C os and K os overcast sky C cs and K cs clear sky C us and K us uniform sky C sv and K sv sky with venetian blind C ug and K ug uniform ground C gv and K gv ground with venetian blind

37. Daylighting Components Illumination on window E kuw = E kw + E uw Illumination on ground E kug = E kg + E ug

38. Daylighting Components Illumination from sky (and sun) on work plane E kwp = E kuw x A g x T g x C x K

39. Daylighting Components Illumination from ground on window E gw = E kug x R g x 0.5 Illumination from ground on work plane E gwp = E gw x A g x T g x C x K

40. Total Daylighting Components Illumination from ground on window E TOT = E kwp + E gwp