Frequently Asked Questions (click to expand each question)
Double insulating glass units consist of two panes of glass that enclose a hermetically sealed air space. The panes are held apart by a spacer around the entire perimeter. The spacer contains a moisture absorbent material called a desiccant that serves to keep the enclosed air free of visible moisture.>
Laminated glass consists of two or more plies of glass interleaved with clear or tinted polyvinyl butyl (PF). The application of heat and pressure bonds the glass and plastic interlayer into one unit. When laminated glass is fractured, the particles of glass tend to adhere to the plastic, affording protection against flying or falling particles. Some combinations of glass and plastic thicknesses do qualify as safety glazing materials under the criteria of ANSI Z97.1-1984 and CPSC 16 CFR 1201.
A sheet or pane of glass
CThe rate of visible light transmission and shading co-efficient (Ke ratio). This is a relationship between how much heat gain is rejected and the amount of visible light transmittal.
Most mirrors are manufactured by the wet chemical deposition method, although a few, for specialized use, are made by vacuum deposition. Safety mirrors are available to meet various laws and building codes. A mirror made from tempered glass will have the inherent distortion from the tempering process and cannot have the same quality in reflection as laminated ones made from mirror quality annealed float glass. Transparent, or two-way mirrors, are designed to allow vision through from one direction while presenting a mirror appearance from the opposite side. Their major application is to permit undetected observation for study or surveillance in places such as prisons, gambling casinos and psychiatric treatment centers. A difference in lighting level is necessary; in the room to be studied the lighting level should be at least five times greater than the lighting level in the observation room; ten times greater is even more effective. Two way mirrors are not intended for use in exterior walls.
The portion of a blast wave, also known as "suction phase", whose pressure is below ambient.
A glass-filled division of a window, door, or wall, or the glass itself.
Plate glass, manufactured by the grinding and polishing process, is no longer produced in the United States, and words referring to it have been eliminated from the ASTM Specification C103685. It has been replaced by the float glass process.
The portion of a blast wave whose pressure is above ambient.
The amount of pressure felt by an object standing directly in the path of an expanding blast wave.
Reflective glassis a clear or tinted glass, coated with an extremely thin layer of metal or metallic oxide.
The rolled glass process consists of pouring molten glass from a furnace, then feeding it through rollers to produce the desired thickness. The glass ribbon is then cooled under controlled conditions. There are three general types of rolled glass: figured / patterned, wired and art / opalescent / cathedral glass.
The ratio of solar heat gain passing through a glazing system to the solar heat gain that occurs under the same conditions if the window were made of clear, unshaded, double strength window glass. The lower the number, the better the shading qualities of the glazing system.
The Sheet glass process accounts for a very small portion of U.S. glass production. Some imported sheet glass will continue to be used, mainly in thickness of 1/8" and less.
The pressure felt on the sides and top of an object as the blast pressure wave envelops and passes over and around it.
The horizontal structure that supports the upright portion of a window frame.