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Glass · Reference

Ug value table for double and triple glazing

4-16-4 with argon and a soft low-E coating (ε 0.03): Ug 1.1 W/(m²·K). The same unit with air and no coating: 2.7. A triple 4-16-4-16-4 with argon and two coatings: 0.6. Below, the usual make-ups with air, argon or krypton and each coating the SyntaxFlow calculator offers. Every figure is worked out by that calculator, and opens it with the same unit filled in.

Double glazing

Panes in the order of the make-up, outside first, and one low-E coating in the cavity. Ug in W/(m²·K), rounded to 0.1; the calculator shows the same result to two decimals, with the working.

Double glazing: Ug in W/(m²·K)
Make-up, mmε 0.837uncoatedε 0.16hard coatε 0.05soft coatε 0.03high-performance soft coatε 0.013best available
Air
4-10-43.02.11.91.81.8
4-12-42.91.91.71.61.6
4-14-42.81.81.51.41.4
4-15-42.81.71.41.41.3
4-16-42.71.71.41.31.3
4-18-42.71.71.41.41.3
4-20-42.81.71.41.41.3
6-12-62.81.91.61.61.5
6-16-62.71.71.41.31.3
Argon 90 %
4-10-42.81.81.51.41.4
4-12-42.71.61.31.31.2
4-14-42.61.51.21.11.1
4-15-42.61.51.21.11.0
4-16-42.61.51.21.11.0
4-18-42.61.51.21.11.1
4-20-42.61.51.21.11.1
6-12-62.71.61.31.31.2
6-16-62.61.51.21.11.0
Krypton 90 %
4-10-42.61.41.11.01.0
4-12-42.61.41.11.11.0
4-14-42.61.51.11.11.0
4-15-42.61.51.11.11.0
4-16-42.61.51.11.11.0
4-18-42.61.51.21.11.0
4-20-42.61.51.21.11.1
6-12-62.61.41.11.01.0
6-16-62.61.51.11.11.0

Triple glazing

Two cavities of the same width and the same gas; in the coated columns, one coating in each cavity.

Triple glazing: Ug in W/(m²·K)
Make-up, mmε 0.837uncoatedε 0.16hard coatε 0.05soft coatε 0.03high-performance soft coatε 0.013best available
Air
4-10-4-10-42.01.31.11.11.0
4-12-4-12-41.91.11.00.90.9
4-14-4-14-41.81.00.90.80.8
4-16-4-16-41.81.00.80.80.7
4-18-4-18-41.81.00.80.80.7
Argon 90 %
4-10-4-10-41.81.00.90.80.8
4-12-4-12-41.80.90.70.70.7
4-14-4-14-41.70.90.70.60.6
4-16-4-16-41.70.90.70.60.6
4-18-4-18-41.70.90.70.60.6
Krypton 90 %
4-10-4-10-41.70.80.60.60.5
4-12-4-12-41.70.80.60.60.5
4-14-4-14-41.70.80.60.60.6
4-16-4-16-41.70.80.60.60.6
4-18-4-18-41.70.80.60.60.6

How the figures are worked out

Centre-of-glass Ug by the EN 673 method the calculator applies: vertical glazing, a mean temperature of 283 K (10 °C) and a temperature difference of 15 K across each cavity, surface coefficients he = 23 and hi = 8 W/(m²·K), glass conductivity 1.0 W/(m·K), uncoated glass emissivity 0.837 and gas fills of 90 % with the rest air. This table is for comparing make-ups, not a declaration: the Ug of a real unit is the one its manufacturer gives for its actual coating and fill, and the whole window (Uw) also depends on the frame and the spacer.

Ug calculatorAny make-up and any widths, with the working: radiation and gas, cavity by cavity. Window U-value (Uw)Put a Ug from this table together with the frame and the spacer for the whole window. Glazing configuratorThe unit layer by layer: Ug, weight, thickness and the faces numbered from outside.