Solar Energy Self Shading Glazing by Jon Watts

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Solar EnergySelf Shading Glazingby Jon Watts
jwatts107_at_ymail.com
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Solar EnergySelf Shading Glazing
History of self glazing glass panels

• Photochromic (commonly known as Transition
  Lens) was first
• developed for eye glasses. This technology was
  developed as a
• way to use the same glasses inside and outside.
  
• These lens are clear when a person is inside and
  darken automatically
• when outside on a sunny day.
• This type of reactive glass blocks 100 percent of
  the suns harmfull
• UV rays.

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Solar EnergySelf Shading Glazing
Existing problems with normal glazing

• Even though double glazed glass exist filled with
• argon gas, there is no way to control the
  amount
• of sunlight or heat from entering the room.
• The only way to prevent heat or light from
  entering
• an interior space is to use curtains, blinds, or
  tint which
• is either completely open or closed to sunlight.

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Solar EnergySelf Shading Glazing

• Photochromic, thermochromic, and
  electrochromic glasses
• modify the incoming rays of the sun so that the
  optical
• properties of the glass change i.e. the glass
  darkens.

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Solar EnergySelf Shading Glazing
Types of self shading glazing

• Photochromic Glass
• like transitions lens found in many glasses, will
• immediately tint the panel when the sun
• hits the surface.
• Doesnt require any electrical charge or hands-on
• direction
• Thermotropic Glass
• Unlike the photochromic, this glass reacts to the
  
• amount of heat hitting the surface.
• Electrochromic Glass
• Unlike the other two types of panes, this type of
  glass
• reacts when an electrical current is supplied.

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Photochromic Glass

• Diagram a (strong light source)
• In diagram a you will notice that the
  structure of the sub-microscopic particles of
  silver-halide that are affected by strong light
  are in a miss-aligned state. In this state, the
  transmitted light is deflected and the
  photochromic glass would appear to darken
  (opaque).
• Diagram b (weak light source)
• In the second diagram you will notice that the
  structure of the sub-microscopic particles of
  silver-halide that are affected by a weak light
  source are in an aligned state. In this state,
  light is allowed to transmit past the
  sub-microscopic particles of silver-halide and
  the photochromic glass would appear transparent.

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Thermotropic Glass
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Thermotropic Glass
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Liquid Crystal glass (LCD)

• A LCD consists of three plates of glass, sealed
  around the perimeter. The middle plate consists
  of a layer of liquid crystal fluid.
• Transparent, conductive electrodes are deposited
  on the surface of the back of the front glass
  plate. The electrodes define individual fields in
  which the special symbols of the display are
  held.
• Removing the voltage from the front plate
  segments has the effect of altering the alignment
  of the crystals so that light may now pass
  through them, making them appear clear.
• Therefore, as a voltage is either applied to or
  removed from the individual segment electrodes on
  the front plate, the LCs behind these segments
  on the middle plate either darken or lighten.

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Electrochromic glass

• Unlike Liquid Crystal (LCD) technology,
  electrochromic glass only requires
• an electric charge to darken.

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Solar EnergySelf Shading Glazing
Bibliography

• Competing Technologies-How Stuff Works by Kevin
  Bonsor
• http//Hc.howstuffworks.com
• TLC Home How Smart Windows Work
• By Kevin Bonsor
• http//tlc.howstuffworks.com/home/smart-window/htm
  
• Smart Glass Wikipedia
• http//en.wikipedia.org/wiki/smart_glass