utility

• Daylighting


  The placement of windows or openings and reflective surfaces in order that sunlight can provide effective lighting into the building interiors
• Daylighting


  The integration of natural light into the building interior spaces where task lighting is not the primary consideration, as in corridors, lobbies and residences
• Components of Daylighting


  • Direct sun
  • Diffuse sky
  • Indirect sun – sunlight reflected from the ground or adjacent structures

  
• Need for Daylighting


  • The cost of money (buying power) is decreasing
  • Energy cost is increasing
  • Demand for "green" or sustainable design in buildings
• Benefits of Natural Light

  • Improved mood and morale – workers have greater job satisfaction
  • Less fatigue – people feel less "stressed out"
  • Reduced eyestrain – natural light is motivating and calming
  • Improved "connection" with outside environment – likely to have a sense of what is happening outside
• Offices – improved productivity, reduced stress, lower absenteeism and turnover
• Educational space – improved attendance and academic performance
• Healthcare space – reduced strain and fatigue for staff; improved well-being of patients
• Industrial space – improved safety and productivity
• Retail space – more customers and increased sales
• Methods to introduce light into buildings

  • Perimeter Lighting – use of windows and light shelves
  • Top Lighting – use of skylights, clerestories and monitors
  • Core Lighting – use of atrium and light wells
  • Optical Lighting – use of fiber optics, prisms, mirrors, parabolic reflectors and other means

  
• Windows


  • Place window close to a light colored wall
  • Slant the sides of window openings so the inner opening is larger than the outer opening
  • Use a large light colored window sill to project light into a room
• Rooms intended for any use, not provided with artificial ventilation system, shall be provided with a window or windows with a total area of openings equal to at least 10% of the floor area of the room, provided that such opening shall be not less than 1.00 square meter
• Toilet and bath rooms, laundry rooms and similar rooms shall be provided with windows or windows with an area not less than 1/20 of the floor area of such rooms, provided that such opening shall not be less than 240 square millimeters
• Required windows may open into a roofed porch where the porch abuts a court, yard, public street or alley, or open watercourse and other public open spaces, has a ceiling height of not less than 2.70 meters, and has one of the longer sides at least 65% open and unobstructed
• Eaves, canopies, awnings (or media agua) over required windows shall not be less than 750 millimeters from the side and rear property lines
• There shall absolutely be no openings on/at/within/through all types of abutments (such as firewalls) erected along property lines except for permitted vent wells
• Requirements for emergency egress windows

  • They can be opened from the inside without the use of any tools
  • The minimum clear opening shall have a width not less than 820 millimeters and a height of 1.00 meter
  • The bottom of the opening should not be more than 820 millimeters from the floor
  • Where storm shutters, screens or iron grilles are used, these shall be provided with quick opening mechanism so that they can be readily opened from the inside for emergency egress and shall be so designed that when opened they will not drop to the ground
• Determining the Average Daylight Factor (ADF) and Average Light Level (ALL)

  1. Solve for Average Daylight Factor (ADF)

  2. Solve for Average Light Level (ALL)

  3. Check if the Average Light Level (ALL) is within the Recommended Daylight Level (RDL) range

  4. Recommendations if ALL is below minimum RDL

  
• The depth of the daylight penetration is about 2.5 x the height of the window opening measured from the floor to the window head
• Window Height to Depth of Penetration of Light

  • A 2.40 to 2.70 meter high window will give full daylight to a depth of about 4.50 meters. As window height increases, depth increases at a ratio of 1 to 2.
  • A 2.40 to 2.70 meter high window will give partial daylighting (requiring additional artificial lights) to a depth of about 6.00 to 9.00 meters. As window height increases, depth increase at a ratio of 1 to 3.
• To get even light distribution, a window opening should be at least half (50%) as wide as the length of its wall
• Light shelves


  • They project beyond the window face and reflect sunlight upwards to illuminate the ceiling
  • The reflected light may contain little heat and typically reduces deep shadows, thus reducing the need for artificial lighting
• Types of Toplighting


  • Skylights
  • Light tubes
  • Clerestories
  • Monitors
• Skylights


  Horizontal windows, roof lantern, light tubes placed at the roof and used to admit light to the spaces below

  
• Clerestory


  An upper zone of wall pierced with windows that admit light to the center of a lofty room
• Monitor


  A raised section of a roof, usually straddling a ridge; has openings, louvers, or windows along the sides to admit light or air
• Toplighting guidelines


  • Skylight Opening: 5% to 10% (maximum) of ceiling area, space at 1 to 2 times the ceiling-to-work plane height
  • Clerestory Opening: 10% of wall area, space 1.50 times the ceiling-to-work plane height, at a point 4.50 meter from the rear wall provide 50 mm of glazing height per 10 footcandle on average work plane
• Small skylights at 3.00 meter ceiling height should be spaced at 3.00 meters. Greater or less ceiling height can be determined by a ratio of 1:1.
• Clearstories at a 4.00 meter ceiling height should be spaced at 6.00 meters. Greater or less ceiling height to spacing can be determined by a ratio of 1 : 1.5.

  
• Large skylights (larger than 3.00 square meters) at a ceiling height of 4.50 meters should be spaced at 9.00 meters. Greater or less ceiling height to spacing can be determined by a ratio of 1 : 2.
• Skylight


  • 5% to 10% (maximum) of ceiling area, space at 1 to 2 times the ceiling-to-work plane height
• Clerestory (Clearstory) Opening


  • 10% of wall area, space 1.50 times the ceiling-to-work plane height, at a point 4.50 meter from the rear wall: for clear climate (5000 footcandle), provide 50 mm of glazing height per 10 footcandle on average work plane
• Skylight/ Clearstory Spacing


  1. Small skylights at 3.00 meter ceiling height should be spaced at 3.00 meters, greater or less ceiling height can be determined by a ratio of 1:1

  2. Clearstories at a 4.00 meter ceiling height should be spaced at 6.00 meters, greater or less ceiling height to spacing can be determined by a ratio of 1 : 1.5

  3. Large skylights (larger than 3.00 square meters) at a ceiling height of 4.50 meters should be spaced at 9.00 meters, greater or less ceiling height to spacing can be determined by a ratio of 1 : 2
• North light should be used where soft, cool, uniform illumination is needed
• Skylights can be a problem due to heat gain from too much sunlight
• Skylights and clerestories can be used to deliver light deep into the interior of a building
• Clerestories can be designed to best avoid direct sunlight
• Light Tube


  A device placed into a roof and admits light to a focused area of the interior, resembling recessed ceiling light fixtures, with less heat transfer than skylights
• New forms of daylighting

  • Pipe Lighting
  • Translucent roof membrane