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Ball State Architecture | ENVIRONMENTAL SYSTEMS 1 | Grondzik 1
DAYLIGHTINGCONCEPTS
Mt. Angel Library by Alvar Aalto; featuring a major daylight “fixture”
Ball State Architecture | ENVIRONMENTAL SYSTEMS 1 | Grondzik 2
Daylighting
Daylighting has always been of major importance, but somehow during the 1960s, we forgot everything we knew
about the art and science of daylighting. Cheap energy and air conditioning
did us in.
William Caudill in the Foreword to Daylight in Architecture
a reference to the allure and power of active systems
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Ball State Architecture | ENVIRONMENTAL SYSTEMS 1 | Grondzik 3
^^ Kimbell Art Museum, Ft. Worth, TX
Mt. Angel Library, Mt. Angel, OR >>
daylighting offers great opportunities for creative design
Ball State Architecture | ENVIRONMENTAL SYSTEMS 1 | Grondzik 4
Daylight Components
The daylight reaching a given point within a building generally consists of a mix of the following components (which show up as variables in some design analysis methods):
a sky component (SC)
an externally reflected component (ERC) an internally reflected component (IRC)
these components are related to — but not the same as — the direct, diffuse, and reflected components that comprise light falling on an aperture
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Ball State Architecture | ENVIRONMENTAL SYSTEMS 1 | Grondzik 5
Daylight Components
DF = SC + ERC + IRC
the “sky” component is not the same as “direct solar” radiation
Ball State Architecture | ENVIRONMENTAL SYSTEMS 1 | Grondzik 6
A Daylighting Design Process
• Establish lighting system Owner’s Project Requirements• Daylighting may be a reasonable means of achieving OPR• If so, select a likely daylighting implementation method
(an approach or approaches)• Validate that the approach actually works (that the result
can meet intent and criteria) using appropriate design tools• Refine the initial design solution as required using
appropriate analysis tools; validate the final design solution• Develop construction drawings and specifications• Apply the commissioning process to the daylighting system
design (especially controls)• Construct the daylighting system and commission it• Occupy building; validate system in place and in use; learn
and communicate the lessons learned
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Daylighting Design Concerns
• The source of light is variable– addressed through the design process
– addressed via coordination with electric lighting
– addressed during usage by space occupants and controls
• The source of light is outside the building– light must be brought into a building
– light must be skillfully distributed from an aperture located at the periphery of a space
These are primarily architectural design issues– architects must take the lead
– daylighting potential is established with the first design moves (plan, orientation, and massing)
Ball State Architecture | ENVIRONMENTAL SYSTEMS 1 | Grondzik 8
General Daylighting Approaches
• Sidelighting– Unilateral or bilateral– Windows– Clerestories (if low)
• Toplighting– Skylights– Clerestories (if high)
• Hybrids and combinations
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what about “bottomlighting”?
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Sidelighting (if unilateral)
illuminance drops off fairly quickly as distance from aperture increases
illuminance pattern (lux, FC or DF) on horizontal task plane
Ball State Architecture | ENVIRONMENTAL SYSTEMS 1 | Grondzik 10
Sidelighting (if bilateral)
illuminance drops off fairly quickly as distance from aperture increases;but two opposing apertures help to balance light distribution across space;magnitude of drop-off is a function of distance between apertures
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Toplighting (if single aperture)
illuminance drops off fairly quickly as distance from edge of aperture increases
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Hybrid Approaches
illuminance from skylight fills in “gap” caused by sidelight distribution pattern;
overlapping patterns will increase illuminance
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Elements of a Daylighting System
• Daylight source the sky (not direct sun)
• Apertures (openings—such as windows or skylights)
• Aperture modifications (lightshelves, shading devices, glazings, jambs, mullions, screens, …)
• Space geometry (length, width, height of room)
• Surface reflectances (of ceiling, walls, floor, furniture, …)
• The illuminated thing (task, surface, …)
• User perceptions
Ball State Architecture | ENVIRONMENTAL SYSTEMS 1 | Grondzik 14
Daylighting System Elements
• Source (the sky not direct solar)– Macro scale: this is a function of geographic locale
– Micro scale: influenced by specific site conditions
• Apertures (openings)– These are a function of design decisions (placement in
building, size, number, orientation)
• Aperture modifications (lightshelves, shading devices, glazings, …)– These are a function of design decisions (and, to some
extent, product availability)
the site provides a resource that the designer can use, abuse, or ignore
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Ball State Architecture | ENVIRONMENTAL SYSTEMS 1 | Grondzik 15
Daylighting System Elements
• Space geometry– This is a function of design decisions optimize
space layout and use the space itself to help distribute light
• Reflectances – These are a function of design decisions use
reflective surface finishes to spread light
• Illuminated thing (task, surface, …)– This is a function of space type and usage
good daylighting design is good architectural design
Ball State Architecture | ENVIRONMENTAL SYSTEMS 1 | Grondzik 16
More About Daylighting Glazing
• Glazing location (orientation, tilt, surroundings) is important
• Glazing aperture area and DF are related in a generally linear manner
• Usually, daylighting glazing should have a high VT (visible transmittance) and a low SHGC (solar heat gain coefficient)—characteristics that will be incompatible in many typical products
• Generally daylighting should involve no direct solar radiation (provide shading devices to ensure this without blocking diffuse daylight)
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More About Lightshelves
These elements are used with daylighting windows to more evenly distributedaylight in a space; they do not substantially increase the amount of daylight that is captured
– They can be external, internal, or both
– When used, they split a window area into “view” and “non-view” sections
– They can assist with shading against direct solar radiation (thus reducing heat gain and glare)
– Performance is not well documented—lightshelf design is more an art than a science
Ball State Architecture | ENVIRONMENTAL SYSTEMS 1 | Grondzik 18
Lightshelves
Inland Revenue (UK), image from LBL
exterior lightshelves, Milwaukee, winter
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Philips Exeter Academy, Exeter, NH; Library, Louis Kahn (1967)
campus contextbuilding context
Daylighting Example
Ball State Architecture | ENVIRONMENTAL SYSTEMS 1 | Grondzik 20
building massing
façade texture and layers
Philips Exeter Academy
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reading carrels and lounge area
Philips Exeter Academy
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grand entry staircase and structure
Philips Exeter Academy
note difference in “warmth” of light
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various views of structure (contrast of wood and concrete)
Philips Exeter Academy
Ball State Architecture | ENVIRONMENTAL SYSTEMS 1 | Grondzik 24
views up into central volume, showing minimal toplighting and smoke vents
Philips Exeter Academy
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bookshelf engages structure
user of stair engages structure
Philips Exeter Academy
Ball State Architecture | ENVIRONMENTAL SYSTEMS 1 | Grondzik 26
exterior courtyard (note vegetative shading) meeting room
Kimbell Art Museum, Dallas, TX; Louis Kahn (1972)
Daylighting Example
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images from: http://www.kimbellart.org/
exterior view
gallery interior
Kimbell Art Museum
Ball State Architecture | ENVIRONMENTAL SYSTEMS 1 | Grondzik 28
images from: http://www.kimbellart.org/
gallery interiordaylighting fixture
Kimbell Art Museum
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images from: http://www.kimbellart.org/
gallery visually open to courtyardexterior view
Kimbell Art Museum
Ball State Architecture | ENVIRONMENTAL SYSTEMS 1 | Grondzik 30
Emerald People’s Utility District Offices, Eugene, OR; Equinox Design
south façade with fixedand vegetative shading
Daylighting Example
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lightshelf (at south window)
north façade, note glazing sections, no exterior shading
Emerald People’s Utility District Offices
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south façade, note fabric shading devices
Emerald People’s Utility District Offices
break room, note direct solar infusion
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it takes more than an aperture to make a good daylighting system
skylight, unnamed architecture building (think about maintenance)
Ball State Architecture | ENVIRONMENTAL SYSTEMS 1 | Grondzik 34
Phoenix Convention Center
some serious external shadingshading, more and less, from glass
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Why CarbonDioxide Matters
http://img257.imageshack.us/i/3way8fp.png/
Ball State Architecture | ENVIRONMENTAL SYSTEMS 1 | Grondzik 36
Why Reducing Carbon Emissions Matters
http://www.msnbc.msn.com/id/9527485/
Fall 1979 Fall 2005