ISO/TC 160/SC 2/WG 2 - Light and energy transmission properties and thermal properties of glazing

ISO 9050:2003 specifies methods of determining light and energy transmittance of solar radiation for glazing in buildings. These characteristic data can serve as a basis for light, heating and ventilation calculations of rooms and can permit comparison between different types of glazing. ISO 9050:2003 is applicable both to conventional glazing units and to absorbing or reflecting solar-control glazing, used as glazed apertures. The appropriate formulae for single, double and triple glazing are given. Furthermore, the general calculation procedures for units consisting of more than components are established. ISO 9050:2003 is applicable to all transparent materials. One exception is the treatment of the secondary heat transfer factor and the total solar energy factor for those materials that show significant transmittance in the wavelength region of ambient temperature radiation (5 microns to 50 microns), such as certain plastic sheets.

Gives a measuring method used to determine the U value (thermal transmittance) of multiple glazing with flat and parallel surfaces. Structured surfaces may be considered to be flat.

Specifies a measuring method used to determine the coefficient of thermal transmittance, the U-value, of multiple glazing with flat and parallel surfaces, including cast and figured rolled glass. Applies to multiple glazing with outer panes which are not transparent to far-infrared radiation, which is the case for normal window glass. Internal elements may be far-infrared transparent.

Applies to glass, coated glass and materials opaque in the far infrared wavelengths. Gives the fundamental rules for calculating the thermal transmittance in the glazing central area (edge effects are not included). The rules are intended to enable the heat loss through glazing in a building to be estimated from the U values and, together with heat losses through the opaque elements of the building, are used to determine the capacity of the heating or cooling plant. In addition, U values for other purposes (e.g. condensation on glazing surfaces, seasonal heat loss through glazing) can be calculated using the same procedure.

Specifies Methods of determining light and energy transmission of solar radiation for glazing units in buildings. These characteristics can serve as a basis for light, heating and ventilation calculations of rooms. Applies both to conventional glazing units and to absorbing or reflecting solar-control glazing units. The appropriate formulae for single, double and triple glazing units are given. Applies to all transparent materials except those which show significant transmission in the wavelength region of ambient temperature radiation, such as certain plastic sheets.