Solar Energy Self Shading Glazing by Jon Watts

Solar Energy Self 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 sun’s harmfull UV rays.

Solar Energy Self 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.

Solar Energy Self 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.

Solar Energy Self 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. Doesn’t 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.

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.

Thermotropic Glass

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. 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. 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. 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 LC’s behind these segments on the middle plate either darken or lighten. Therefore, as a voltage is either applied to or removed from the individual segment electrodes on the front plate, the LC’s behind these segments on the middle plate either darken or lighten.

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

Solar Energy Self Shading Glazing Bibliography Competing Technologies-How Stuff Works by Kevin Bonsor TLC Home “How Smart Windows Work” By Kevin Bonsor Smart Glass – Wikipedia