BS 6993-2:1990

This standard BS 6993-2:1990 Thermal and radiometric properties of glazing is classified in these ICS categories:

• 81.040.20 Glass in building

This Part of BS 6993 describes a method for measuring the U-value (thermal transmittance) of the central area of single, double or multiple glazing using hot-box apparatus complying with BS 874-3.1. The edge effect, due to the thermal bridge through the spacer of double or multiple glazing, is effectively eliminated in this method.

The method is designed to measure the U-value of the glazing alone, i.e. the glass (or alternative glazing material) and any enclosed air space, and the additional information required in the test reports of clause 8 and A.9 of BS 874-3.1:1987.

Appendix A specifies values to be used in the calculation of a U-value in accordance with BS 6993-1, when such a calculated value is to be compared with that obtained by direct measurement in accordance with this Part of BS 6993.

Appendix A gives a worked example, which illustrates the use of this Part of BS 6993.

NOTE The titles of the publications referred to in this standard are listed on the inside back cover.

Method for measuring the transmittance of the central area of single, double or multiple glazing using hot box apparatus complying with BS 874-3.1. The edge effect due to the thermal bridge through the spacer of double or multiple glazing is effectively eliminated by this method.