1. Environmental Sciences II AR 832 Joseph Kennedy Winter 2015 WEEK 3 1

2. SHADING SHADING BASICS ORIENTATION OF SHADING DEVICES MOVABLE SHADING DEVICES SHADING PERIODS OF THE YEAR HORIZONTAL OVERHANGS SHADING DESIGN FOR SOUTH WINDOWS –FIXED SOUTH OVERHANGS –MOVABLE SOUTH OVERHANGS SHADING FOR EAST AND WEST WINDOWS –HORIZONTAL OVERHANGS –SLANTED VERTICAL FINS FINS ON NORTH WINDOWS

20. BRISE-SOLEIL

21. SUN BREAKER

22. Gustavo Capanema Palace in Rio de Janerio

23. SUN (by Le Corbusier) AN ENEMYA FRIEND

24. SOLAR RADIATION Heat energy from the sun is constantly changing into radiant energy, and this radiant energy is being partly changed back into heat energy upon entering another body. –This is very apparent on a cold day to feel the warmth of the sun on your back. –X-Hay, ultra-violet rays, infra-red are other examples of radiant energy.

26. DIRECT – DIFFUSE RADIATION Direct insolation is the solar irradiance measured at a given location on Earth with a surface element perpendicular to the Sun's rays, Units: 1 kW·h/(m²·day) = 1,000 W · 1 hour / ( 1 m² · 24 hours) = 41.67 W/m² Diffuse insolation is the solar radiation that is scattered or reflected by atmospheric components in the sky. 26

28. Ref: http://www.architecture.uwaterloo.ca/faculty_projects/terri/carbon-aia/strategies1a.html

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30. Ref: http://www.architecture.uwaterloo.ca/faculty_projects/terri/carbon-aia/strategies1a.html REVIEW

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32. Solar Energy / Passive Design Architectural Graphic Standards

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34. REFLECTION; TRANSMISSION; ABSORPTION Radiant energy is traveling through space at a rate of 186,000 miles a second. However, when it comes into contact with a body, generally three things happen to it: –REFLECTION: If radiant energy comes into contact with a body such as a silver mirror, almost all the energy is reflected. –TRANSMISSION: If radiant energy comes into con- tact with a body such as a window pane, almost all the energy will pass through it. –ABSORPTION: If radiant energy comes into contact with a body that is black. almost all the energy will be absorbed.

35. FIXED SHADING DEVICES

37. MOVABLE SHADING DEVICES

39. ENVELOPE VS. INTERNALLY DOMINATED BUILDING TYPES

41. BALANCE POINT TEMPERATURE The outside temperature at which the building makes a transition from a heating need to a cooling need determines when heating and cooling are required. BALANCE POINT = Heat generated inside the building balances the building’s heating loss, to maintain a desired inside temperature. If balance point is 50 deg F: If ambient (outside temp) > 50 cool the bldg If ambient (outside temp) < 50 heat the bldg

42. = TECHNIQUE 22- BALANCE POINT TEMPERATURE

43. SHADING CALENDAR Sunpath same for two dates (same sun angles) – e.g., March 21 and September 21. However, shading requirements (responses) may be different. Building require shading whenever outside temp is above the balance point temp. TMY data is needed to generate “Shading Calendars”. TMY available from NOAA.

45. GRAY AREAS = BPT to BPT+14 BLACK AREAS = BPT + 15 and up

49. DESIGN GUIDELINES FOR FIXED SOUTH OVERHANGS

51. FIXED SOUTH OVERHANGS

56. MOVABLE SOUTH OVERHANGS

57. Ref: http://www.architecture.uwaterloo.ca/faculty_projects/terri/carbon-aia/strategies1a.html EAST AND WEST WINDOWS

61. EAST AND WEST HORIZONTAL OVERHANGS

63. SLANTED VERTICAL FINS EAST AND WEST WINDOWS

64. SLANTED VERTICAL FINS EAST AND WEST WINDOWS

65. SLANTED VERTICAL FINS PLAN VIEW

66. GLAZING AS THE SHADING ELEMENT EAST & WEST SIDE

70. Shading Coefficients (SC) and Solar Heat Gain Coefficients (SHGC) for various shading devices

76. Solar Energy / Passive Design South-facing OpeningsEast & West-facing Openings

77. HEAT TRANSFER EQUATION Q = U A (t 1 – t 2 ), U= 1/R Q = Rate of heat flow BTU per HOUR U 0 = Overall conductance BTU per HOUR per SF per ºF (coefficient of transmission ) A = Area of construction SQUARE FEET t 1 = Warm side temperature ºF t 2 = Cool side temperatureº F BTU / HR = (BTU / HR / SF / º F) (SF) ( º F) WHEN t 1 = t 2 NO HEAT TRANSFER OCCURS WHEN t 1 AND t 2 VARY BUT REMAIN CONSTANT A STEADY STATE OF HEAT TRANSFER OCCURS

78. HAND CALCS Use kWh or Therms