| Glossary |
Asbestos |
a group of fibrous minerals which occur as small veins in the massive body of natural hydrous silicates of serpentine or amphobole, and have heat-, fire-, and solvent-resistant prop. |
Batt |
a pc. of insulation, of the flexible type, cut into easily handleable sizes, square or rectangular in shape, usually 24” or 48” long and with an aluminum foil on one side, and with, or without, a container sheet on the other side. |
Binder |
the cementing material used to bond fibers, flakes, granular materials together. |
Blanket insulation |
a flat flexible type of insulation formed into sheets or rolls. These blankets may be faced or coated on one or both sides. |
Cellular Plastic |
a plastic whose apparent density is decreased substantially by the presence of numerous cells disposed throughout its mass. |
Closed-Cell Foamed Plastic |
a cellular plastic in which there is a predominance of non-interconnecting cells. |
| Conduction |
the direct flow of heat through a material resulting from physical contact. |
| Convection |
the transfer of heat in fluid or air, caused by the movement of the heated air or fluid itself. |
| Density (apparent) |
the weight of a unit of volume of a material in its manufactured state, including all voids; usually expressed in pounds per cubic foot (pcf) or kgs. per cubic meter (kg/m3). |
| Emittance |
refers to the ability of the surface to emit radiant energy. Emissivity ranges from 0 to 1 and a lower value indicates a reflective surface with a low level of radiation. |
| Facing |
a thin layer, usually factory applied, on the surface of an insulating panel, variously acting as a vapor-barrier, weather-barrier, protector from damage, and a decorative coating. |
| Fire Retardance |
that property of a material which delays the spread of fire, either through or over itself. |
| “R” Value |
see Thermal Resistance |
| Radiant Barrier |
a reflective surface that intercepts the flow of radiant energy. |
| Radiation |
the transfer of energy from a higher temp. body, through space, to another body, or bodies, some distance away at a lower temp., without raising the temp. of the medium through which the energy passes. |
| Reflectance |
refers to the fraction of incoming radiant energy that is reflected from the surface. |
| Self-Ignition Temp. |
the lowest temp. of a material which will cause it to ignite without other ignition source. |
| Self-Extinguishing |
that property of a material which enables it to stop its own ignition after external ignition sources are removed. |
| Thermal Conductance (C-value) |
the amt. of heat transferred through a unit area of a material in a unit time, through its total thickness, with a unit of temp. diff. bet. the surfaces of the two opposite sides. |
Thermal Conductivity
(K-value) |
the amt. of heat transferred through a unit area of a material in a unit time, through a unit thickness, with a unit of temp. diff. bet. the surfaces of the two opposite sides. |
| Thermal Insulation |
material having air- or gas-filled pockets, void spaces, or heat-reflective surfaces, which, when properly applied, will retard the transfer of heat with reasonable effectiveness under ordinary conditions. |
Thermal Resistance
(R-value) |
that property of a material which enables it to withstand the passage of heat through it, due to a temp. diff. bet. its two opposite surfaces. |
| Vapor-Barrier |
a material which when installed on the high vapor pressure side, retards the passage of the moisture vapor to the lower vapor pressure side. |
