Facades and Summer Performance of Buildings - Low Energy Cooling for Sustainable Buildings - page 37

Figure 2.9 Detailed view of double fa¸ade with monitoring equipment

double-glazed fa¸ade system was part of an integrated energy concept (AIT, 1998).
The fa¸ade system consists of a 2.95m high and 1.55m wide outer single glazing and
an inner low-e coated double glazing with a U -value of 1.4Wm − 2 K − 1 and a g -value
of 0.62. The air space between both panes is 0.5m, and the openings at the top and
bottom are 0.15m high, which corresponds to 10% free opening section. The external
single glass pane in the fa¸ade is thicker than the laboratory glass (16mm with τ =

0.69 instead of 6mm with τ 0.84), resulting in 13% less optical transmission; the

other optical characteristics are the same.
The sun shading system installed consists of lamellae of 0.05m width, which are
mounted at a distance of 0.175m from the outer single glazing. Three cases with
different opening positions of the shading devices were compared. Case A: without
sun blind; Case B: sun blind with 45 ◦ lamella position; Case C: sun blind totally closed
(see Figure 2.11).

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Figure 2.10 Office building with double fa¸ade system in Stuttgart, Germany