Presentation is loading. Please wait.

Presentation is loading. Please wait.

Daylighting: Accident or Technology? Marc Schiler Schiler & Associates / University of Southern California.

Similar presentations


Presentation on theme: "Daylighting: Accident or Technology? Marc Schiler Schiler & Associates / University of Southern California."— Presentation transcript:

1 Daylighting: Accident or Technology? Marc Schiler Schiler & Associates / University of Southern California

2 Technical Approach to Natural Lighting  Provide the light: Building plan, section and orientation Fenestration location and sizing  Lighting circuits and controls Balance the availability of natural light Shutoff in stages  Sensors Occupancy sensors Photosensors

3 Aesthetic Approach to Natural Lighting  Provide the space: Building plan, section and orientation Fenestration location and sizing  Colors, reflective forms and gradation Show the sensuous nature of the space Reinforce the design concept and parti  Reinforce the function Avoid glare Provide visual terminus(humans are phototropic)

4 Five Topics:  Topic One: Technical –Concepts and Strategies  Topic Two: Aesthetic –Examples and Images  Topic Three: Models –Simulating Daylight with Physical Models  Topic Four: Calculations –Rules of Thumb and Calculations  Topic Five: Equipment –Sensors and Controls

5 Topic One  Technical: Concepts and Strategies

6 Agenda for Topic One  Benefits  Strategies and Elements  Definition of Terms  Design Guidelines

7 Benefits  Quantitative –Cost savings for user –Peak Reduction –Sustainability  Qualitative –Color Rendering –Productivity –Connection

8 Prototype Strategies  Foot Prints  Clerestories  Sawtooth  Skylights  Light Shelves  Atria  Exotica

9 Foot Prints

10 Clerestories

11 Sawtooth

12 Skylights  Caveat: –Lower winter angles = less light –Higher summer angles = more heat

13 Light Shelves

14 Light Pipes

15 Atria / Light Wells

16 Fresnel Lenses and Holographic Films

17 Design Guidelines  Basic Principles –illuminance vs. luminance  Glare –discomfort glare vs. veiling reflections  Vertical vs. Horizontal  Tips –Bring it in high –Bounce it or filter it –Control it –Harvest it

18 Vertical vs. Horizontal  Solar Control vs. Lighting per glazing area –more light from horizontal glazing, more heat gain in summer, less heat gain in winter –less light from vertical, better distribution, overhang controls for southern orientations, fins for eastern and western orientations (and northern)

19 Single Story  Warehouses  Supermarkets Bldgs.  Light Industrial  Suburban sites

20 Multiple Story  Offices  City Bldgs.  Urban sites

21 Summary (of Topic One)  Strategies and design elements  Design “Tips”

22 Break  Take a break –Stretch your legs –Get some coffee –Get rid of some coffee –Call home

23 Daylighting: Accident or Technology? Marc Schiler Schiler & Associates / University of Southern California

24 Topic Two: Aesthetics  Classics –Older buildings with natural lighting often stand the test of time very well.  Current Examples –Newer buildings enjoy the technique and the technical.

25 Good Examples, Old to New  St. Gallen Abbey Library, Peter Thumb  Bradbury Building  Ventura Coastal Building by Scott Ellinwood  Mt. Airy Library by Ed Mazria  Boy’s / Ralph’s Supermarket  Lyons School of Architecture by Jourda and Peroudin

26 Examples for Varying Functions and Climates  Arab Center, Paris, Jean Nouvel  Episcopal Church, Phoenix  MIT Chapel, Boston, Aero Saarinen  Wells Branch Bank, Minnesota  BRF Office Building, Copenhagen

27 More Examples  Crystal Cathedral, Philip Johnson  North Jutland Art Museum, Alvar Aalto  Menil by Renzo Piano  Kimbell Museum, Louis Kahn  Ronchamps, Le Corbusier  La Tourette, Le Corbusier

28 Note -  The preceding three pages refer to 35mm slide collections of each building.

29 Summary of Part Two  The greatest designs include natural lighting. –Natural light saves energy –Natural light can project in dramatic fashion –Natural light can be bounced and diffused to fill a space  This has proven true throughout history –Rather than fight the architecture, we wish to work with the architecture in the designing the natural and “artificial” lighting to work together.

30 Daylighting: Accident or Technology? Marc Schiler Schiler & Associates / University of Southern California

31 Topic Three: Models  Using Scale Models to Study Light Distribution

32 Daylight Harvesting  Provide the light: –Building plan and orientation –Fenestration location and sizing  Test the design –Physical models –Computer simulations  Lighting circuits and controls –Balance the availability of natural light –Occupancy sensors, Photosensors

33 Agenda for Topic Three  Scales  Examples  Model Craft  Measurement  Photography  Computations

34 Scale #1 - Quick and Dirty  Simple question: –skylight in middle or by the wall? –horizontal skylight or monitor? –eyeball assessment of question  Small Scale: –1/16”=1’-0” to 1/2” = 1’-0” or about 1:200 to 1:20

35 Quick and Dirty (cont’d)  Construction –time: one hour or less –foamcore or chipboard, approximate reflectances –tacky glue, masking tape or even pins –scissors, scrap materials at hand  Time and cost –1/2 hour, $0 - $20

36 Scale #2 - Developmental  Developmental issues: –Sizing issues: “How big should the skylight be?” –Placement/Light distribution: “How close to the wall?” –Details: “How wide or deep should the light well be?” –Actual measurements taken at different times and seasons  Middle Scale: –1” = 1’-0” or about 1:10

37 Developmental (cont’d)  Construction –Correct reflectances, some details like baseboards –simple furniture, critical objects to be lit –more detail, such as mullions to show shadow patterns –specular and diffuse surfaces are differentiated  Time and cost –2 to 4 hours, $30 - $100

38 Scale #3 - Presentation  Qualitative issues: –Calibration against existing space to test proposed renovations –Color interaction, mood, ambience, personal reactions –Search for glare sources, veiling reflections –Photographs taken at different times and seasons  Large Scale: –2” = 1’-0” or about 1:5 or larger

39 Presentation (cont’d)  Construction –Correct colors, complete details like return air grills, blackboards –Complete furniture, with simulated textures –Ceiling treatments, light fixtures, ducts –Dirty surfaces, where appropriate  Time and cost –20 to 100+ hours, $100+

40 Review - Solar Angles  Altitude  Azimuth

41 Solar Gnomons  One for each latitude, gnomon at correct height  Glued to model in relation to model compass  Manipulated to get shadow in the correct position –Azimuth first –Altitude second

42 Solar Gnomon Example 1

43 Model Craft  Joints must be sealed –electrical tape, or aluminum foil taped over all corners and seams  Walls must be opaque –construction paper, opaque internal surface treatments glued to internal surfaces –aluminum foil covering all exterior surfaces (exception: any surface which might reflect light into the model, such as a roof adjacent to a roof monitor or sawtooth)

44 Model Craft (cont’d)  Replaceable parts or oversized parts –Whatever is being tested should fit into a light- leak-proof slot –Prepare modules for each variation in developmental or presentation models –In some cases, testing skylight placement can be done by making an oversize roof, and then sliding it around so that the skylight sits over different areas. One roof and skylight can then simulate many positions without any cutting.

45 Model Craft (cont’d)  Portholes for measurement –allow access for meters and wires, if necessary, and cover the hole if it is possible to read the meter from somewhere else. –if necessary, cut holes in the floor to allow the meter surface to be at the workplane height in the scale of the model

46 Model Craft (cont’d)  Portholes for photography –plan the access for the camera from the desired viewpoints –place portholes at in scale eye position, e.g. 5’-3” in model scale –if multiple views are desired, cover portholes with scale blackboards or paintings so that one porthole is not visible from the other camera angle

47 Review - Measurement  Footcandle or Lux  Suggested Daylight Factors (DF) –What the heck is a daylight factor? E in / E ext hor

48 Measurement Procedures  Grid Record Sheet –Draw a grid of expected measurement points on a sheet of paper, along with headers recording actual time of day and simulated time of day –Xerox enough copies of the sheet for different date or design variations –Record each set of readings onto separate sheets

49 Measurement (cont’d)  Don’t let light in over your shoulder –shade the meters from direct beam for DF values –Don’t let light in through the measurement port (it screws up the measurement) –put a shroud over your head, and tape it to the model, if necessary (black plastic trash bag, double thick, is usually sufficient)

50 Measurement (cont’d)  Do let light in over your shoulder! –when measuring through the active window, be sure that your body stays below the field of view of the window and the meter –don’t shade the meters from direct beam for absolute values

51 Photography  Record date and time –Include the date and time you are simulating within the image itself

52 Photography (cont’d)  Provide a porthole  Don’t let light in over your shoulder –again, put a shroud over your head, and tape it to the model, if necessary (a black plastic trash bag, double thick, is usually sufficient)

53 Slides  Note. At this point the presentation proceeds to proof that this can be done at each scale in the form of a series of 35mm slides of the interiors of real buildings followed by models of the same space, generally indistinguishable.

54 Summary of Topic Three  Scales, costs and functions  Examples  Model Craft  Measurement  Photography

55 Break  Take a break –Stretch your legs –Get some coffee –Get rid of some coffee –Call home

56 Daylighting: Accident or Technology? Marc Schiler Schiler & Associates / University of Southern California

57 Topic Four: Calculations Rules of Thumb and Calculations

58 Agenda for Topic Four  Rule of Thumb Computations –Width to Depth –Percentage Glazing  IES calculation methods –sidelighting –toplighting

59 Design Guidelines (Reminder)  Basic Principles –illuminance vs luminance  Glare –discomfort glare vs veiling reflections  Vertical vs. Horizontal  Tips –Bring it in high –Bounce it or filter it –Control it –Harvest it

60 Reminder of Application Guidelines  Different functions and building forms will require different calculation methods.

61 Vertical vs. Horizontal  Solar Control vs. Lighting per glazing area –more light from horizontal glazing, more heat gain in summer, less heat gain in winter –less light from vertical, better distribution, overhang controls for southern orientations, fins for eastern and western orientations (and northern)

62 Single Story  Warehouses  Supermarkets Bldgs.  Light Industrial  Suburban sites

63 Multiple Story  Offices  City Bldgs.  Urban sites

64 Rules of Thumb for Aperture Sizing  Suggested Daylight Factors (DF) –What the heck is a daylight factor?  Sizing to obtain the suggested DF –What glazing area in which kind of element  Computer Programs –If the client’s got money

65 Suggested Daylight Factors FunctionDFComment Circulation1%vertical surfaces are important Public Spaces>1%more light, more drama Warehouse1.5%higher for tightly packed shelves Office area2-4%filing, reception, general area Detailed office work5%focus on work surface Factory work2-4%dependent on function and danger Detailed manf’g5%tasks requiring high visual acuity Manual drafting, color comparison6%provide one area within the space

66 Sizing From Sidelighting (d < 2.5 x h)Suggested Glazing Area near the front of the spaceDF x Af / 0.5Tg at the middle of the spaceDF x Af / 0.2Tg near the back of the spaceDF x Af / 0.1Tg From ToplightingSuggested Glazing Area Vertical monitorsDF x Af / 0.2Tg North facing sawtoothDF x Af / 0.33Tg Horizontal Skylights*DF x Af / 0.5Tg

67 Example #1  2,000 sf of warehouse, toplighting –forklift access, generous aisles –suggested DF = 1.5% –Transmissivity of glazing = 62% –Horizontal skylights  Go for uniform 1.5% –Ag = DF x Af / 0.5 Tg – =.015 x 2,000sf / (0.5 x.62) – = 96 sf

68 Example # 2 l Go for 3% at middle –Ag = DF x Af / 0.2 Tg – =.03 x 2,000sf / (0.2 x.75) – = 400 sf l Go for 3% at back –Ag = DF x Af / 0.2 Tg – =.03 x 2,000sf / (0.1 x.75) – = 800 sf  2,000 sf of simple office space, sidelighting –non strenous tasks, filing, some computer terminals –suggested DF = 2-4% –depth within 2.5h of window (20 ft of 8 ft window) –Transmissivity of glazing = 75%  Do layout, decide desired daylit depth

69 IES Lumen Method  Tracks light from sky and sun separately  Applies form and reflectance factors to light from ground  Assumes a strip window for the entire length of one wall (as might be found in an office.)

70 IES Lumen Method (cont’d)  Calculates a Coefficient of Utilization (CU) for five locations within the cross section of the space

71 Basic Equation  E i = E x NT CU  where  E i = interior illuminance in lx, E x = exterior illuminance in lx, NT = net transmittance, CU = coefficient of utilization.

72 Sidelighting  E i = E xv τ CU  where  E i = interior horizontal illuminance on a reference point from sidelighting, in lx, E xv = exterior vertical illuminance on the window wall in lx, τ = net transmittance of the window wall, CU = coefficient of utilization.

73 Ground Exitance  M g = ρ g (E xh sky + E xh sun )  where  M g = exitance from the ground in lm/m 2, ρ g = reflectance of the ground, E xh sky = horizontal illuminance from the sky in lx, E xh sun = horizontal illuminance from the sun in lx.

74 Illuminance from Overcast Sky  Refer to IESNA Lighting Handbook, Ninth Edition for complete tables

75 Illuminance from Clear Sky  Refer to IESNA Lighting Handbook, Ninth Edition for complete tables

76 Illuminance from Sun  Refer to IESNA Lighting Handbook, Ninth Edition for complete tables

77 Net Transmittance  τ = T R a T c LLF  τ = net transmittance of window LLF = light loss factor representing dirt accumulation R a = the net-to-gross window area ratio representing such elements as mullions and glazing bars; T c = other elements such as shades and drapes

78 Light Loss Tables (used to be slide 87)  Refer to IESNA Lighting Handbook, Ninth Edition for complete tables

79 CU Sky Component = 0.75  Refer to IESNA Lighting Handbook, Ninth Edition for complete tables

80 CU Ground Component  Refer to IESNA Lighting Handbook, Ninth Edition for complete tables

81 Clear Window Illuminance  E i = τ ( E xv sky CU sky + E xv g CU g )  E i = interior illuminance at a reference point in lx, τ = net transmittance of the window wall, E xv sky = exterior vertical illuminance from the sky on the window in lx, CU sky = coefficient of utilization from the sky, E xv g = exterior vertical illuminance from the ground on the window in lx, CU g = coefficient of utilization from the ground.

82 Diffusing Window Illuminance  E i = 0.5 τ ( E xv sky + E xv g ) ( CU sky + CU g )  E i = interior illuminance at a reference point in lx, τ = net transmittance of the window wall, E xv sky = exterior vertical illuminance from the sky on the window in lx, CU sky = coefficient of utilization from the sky, E xv g = exterior vertical illuminance from the ground on the window in lx, CU g = coefficient of utilization from the ground.

83 Toplighting  E i = E xh τ A s / A w  E i = average incident illuminance on the workplane from skylights in lx, E xh = horizontal exterior illuminance on the skylights in lx, A s = gross projected horizontal area of all the skylights in m 2 A w = area of the workplane in m 2, τ = net transmittance of the skylights and light well, including losses because of solar control devices and maintenance factors, CU = coefficient of utilization.

84 Toplighting (cont’d)  T DM = 1.25 T FS (1.18 - 0.416 T FS )  T DM = dome transmittance, T FS = flatsheet transmittance.

85 Toplighting (cont’d)  T = (T 1 T 2 ) / (1 - ρ 1 ρ 2 )  T 1, T 2 =diffuse transmittances of the individual domes, ρ 1 = reflectance from the bottom side of the upper dom e, ρ 2 = reflectance from the top side of the lower dome.

86 Light Well Equation  WCR = 5h(w +l) / wl  WCR is the well cavity ratio, used to look up the well efficiency N w  h is the well height, w is the well width, l is the well length. (The dimensions h, w, and l must be expressed in the same units.)

87 Light Well Cavity Ratio  Table from IESNA Lighting Handbook, Ninth Edition

88 Diffuse Transmittance  τ d = T d N w R a T c LLF  T d is equal to the diffuse transmittance  N w is the well efficiency  R a = ratio of net to gross skylight area T c = transmittances of diffusers, lenses, louvers, or other controls LLF = the light loss factor from IES tables.

89 Direct Transmittance  τ D = T D N W R a T c LLF  T D is equal to the direct transmittance of the dome  N w is the well efficiency R a = ratio of net to gross skylight area T c = transmittances of diffusers, lenses, louvers, or other controls LLF = the light loss factor from IES tables.

90 Room Cavity Ratio  RCR = 5 h c (l + W) / lw  h c is the height from the workplane to the bottom of the skylight well, l is the length of the room, w is the width of the room. (All three parameters must have the same units.)

91 Room Cavity CU Tables  Refer to IESNA Lighting Handbook, Ninth Edition for complete tables

92 Overcast Sky  E i = E xh sky τ d CU N (A / A w )  E xh sky = exterior horizontal illuminance due to the sky only, in lx, τ d = net diffuse transmittance, τ D = net direct transmittance, CU = coefficient of utilization, N = number of skylights, A = area of each skylight in m 2, A w = area of the workplane in m 2.

93 Clear Sky  E i = (E xh sky τ d + E xh sun τ D ) CU N (A / A w )  E xh sky = exterior horizontal illuminance due to the sky only, in lx, E xh sun = exterior horizontal illuminance due to the sun only, in lx, τ d = net diffuse transmittance, τ D = net direct transmittance, CU = coefficient of utilization, N = number of skylights, A = area of each skylight in m 2, A w = area of the workplane in m 2.

94 Daylight Factor  CIE (European) methods  Less accurate, more flexible, in allowing asymmetrical window placement  PSALI  Some methods only account for overcast conditions

95 Computer Programs  More accurate predictions or renderings –Lightscape –Radiance –Lumen Micro (et al) –Superlite  Payback period, including effect of HVAC –DOE2.1E –MicroDOE, PowerDOE, CECDOE, etc. –HEED, Solar 5

96 Summary of Topic Four  Computational Rules of Thumb  IES Lumen Method –sidelighting –toplighting  Daylight Factor  Computer programs

97 Break  Take a break –Stretch your legs –Get some coffee –Get rid of some coffee –Call home

98 Daylighting: Accident or Technology? Marc Schiler Schiler & Associates / University of Southern California

99 Part Five: Equipment Natural Lighting: Control Devices and Systems

100 Daylight Harvesting  Provide the light: –Building plan and orientation –Fenestration location and sizing  Test the design –Computer simulations –Physical models  Lighting circuits and controls –Balance the availability of natural light –Occupancy sensors, Photosensors

101 Agenda for Topic Five  Controls  California Codes  Typical Circuits  Demonstration  Possible Savings  Dangers and Pitfalls  Walkthrough

102 Review - Terms  Design Level  Circuits  Devices –sensors –power packs –switches

103 Basic Strategy  Circuit layout and sensor placement, daytime

104 Basic Strategy  Circuit layout and sensor placement, nighttime

105 California Code  Must provide possibility for 50% reduction in any room over 100 sq. ft.  Provide separate switching for daylit areas, to allow harvesting  Allowable Lighting Power Density and Actual Lighting Power Density –Credits for daylight sensors –Credits for occupancy sensors –Credits for automatic time controls, etc.

106 California Code (cont’d)  Credit factors for occupancy sensors

107 California Code Required Layouts

108 Control types  Occupancy Sensors  Photosensors  Continuous Dimming vs. Step Dimming  Occupancy and Photosensor Interaction

109 Occupancy Sensors  Ultrasonic –sees around corners –quartz crystal oscillator –multiple receivers –sees inanimate movement, sometimes vibrations  Infrared –line of sight only –ignores movement of same temperature objects –can be aimed and masked

110 Comparison

111 Ultrasonic

112 Infrared

113 Photosensors  Ceiling mounted, viewing workplane

114 Continuous Dimming vs. Step Dimming  Low natural light + single step = no savings  (single step is never activated, light too low)

115 Continuous Dimming vs. Step Dimming  Continuous dimming harvests immediately  (begins @ 100%, reduces to 30%*)

116 Continuous Dimming vs. Step Dimming  Large natural light + single step = big savings  (single step is activated, goes to zero)

117 Continuous Dimming vs. Step Dimming  Plentiful daylight + single step = best value  Lower natural light levels require continuous dimming

118 Typical circuits  Power Pack  Separate low voltage signal  RS-232, EPROM, Carrier Wave and X-10

119 Power Pack  Switches, sensors and outside sources

120 Staged Signals  Interim logic box collects signal data

121 “Intelligent Ballasts”  Separate low voltage signal from sensor to ballasts

122 Possible savings  DOE2.1E –STEPPED vs.CONTINUOUS –LT-REF-PT-1 ( x, y, z) –LT-FRACTION-1 –DESIGN LEVEL –Lighting ->HVAC -> plant -> Economics  HEED, DAYLIT –STEPPED vs. CONTINUOUS –3 zones –DESIGN LEVEL

123 Dangers and Pitfalls  Users –Sensitivity and Time Delay –Incorrect Placement –“Know it All”  Contractors –Upside Down –Wrong Voltage –Passive Circuit to Active Circuit –No Calibration

124 Summary  Controls –Occupancy Sensors –Photosensors –Continuous Dimming vs. Step Dimming –Occupancy and Photosensor Interaction  Code Requirements and Benefits

125 Summary (cont’d)  Typical Wiring Diagrams –Power pack vs. “intelligent ballasts”  Typical Pitfalls  Energy saved  Quality Environment!

126 Overall Summary  Natural Light in Buildings –Provide the light: Building plan, orientation and section Fenestration location and sizing –Lighting circuits and controls Balance the availability of natural light Shutoff in stages –Sensors Occupancy sensors Photosensors

127 Sources for further study  Books: –Ander, Gregg; Daylighting Performance and Design, Van Nostrand Reinhold, New York 1995 –Kaufman, John, et al; IES Handbook; Illuminating Engineering Society (IESNA), New York –Schiler: Simplified Design of Building Lighting, Wiley & Sons, New York 1992 –Schiler et al: Simulating Daylight with Architectural Models, DNNA report

128 Sources for further study (cont’d)  Monographs: –____; RP-5 Recommended Practice of Daylighting; Illuminating Engineering, Society (IESNA), New York –____; RP-21 Calculation of Daylight Availability; Illuminating Engineering Society (IESNA), New York –____; RP-23 Calculation of Daylight; Illuminating Engineering Society (IESNA), New York

129 Finis  Daylighting: Accident or Technology?  Marc Schiler Schiler & Associates / University of Southern California


Download ppt "Daylighting: Accident or Technology? Marc Schiler Schiler & Associates / University of Southern California."

Similar presentations


Ads by Google