BS 6993-1:1989
Superseded
A superseded Standard is one, which is fully replaced by another Standard, which is a new edition of the same Standard.
A superseded Standard is one, which is fully replaced by another Standard, which is a new edition of the same Standard.
Thermal and radiometric properties of glazing Method for calculation of the steady state U-value (thermal transmittance)
Hardcopy , PDF
01-02-2003
English
28-02-1989
Foreword
Committees responsible
Method
1 Scope
2 Definitions
3 Symbols
4 Basic equations
5 Basic material properties
6 Exterior and interior heat transfer coefficients
7 Standardized values
8 Accuracy
Appendices
A Emissivity
B Gas properties
C Heat transfer coefficients
D Examples of U-value calculation for standardized
values
Tables
1 Values of constant C and exponent n
2 Effective emissivity and inter-surface emittance for
one surface glass, one coated low-emissivity surface
3 Effective emissivity and inter-surface emittance for
two similarly coated low-emissivity surfaces
4 Hemispherical emissivity, epsilon h
5 Gas properties at 283 K mean
6 Exterior heat transfer coefficients
7 Interior heat transfer coefficients
Figure
1 Variation of U-value with normal emissivity of air
and argon filled glazing units of 6 mm glass
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