advanced building skins 14 | 15 June 2012 - lamp.tugraz.at - Graz ...
advanced building skins 14 | 15 June 2012 - lamp.tugraz.at - Graz ...
advanced building skins 14 | 15 June 2012 - lamp.tugraz.at - Graz ...
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
Tdd [-]<br />
Advanced Building Skins<br />
The energy consumption of <strong>building</strong>s is typically in the form of he<strong>at</strong> or electricity. Thermal energy is<br />
required to either he<strong>at</strong> or cool the <strong>building</strong> to a desired oper<strong>at</strong>ion temper<strong>at</strong>ure. Thus the energy<br />
required is rel<strong>at</strong>ed primarily to the type of <strong>building</strong> usage and the thermal losses or gains through the<br />
<strong>building</strong> envelope. This correl<strong>at</strong>ion is mainly described by the U value and g value of the product or<br />
the combin<strong>at</strong>ion of products.<br />
Irradi<strong>at</strong>ion<br />
Reflection<br />
Absorption<br />
Transmission<br />
Secondary he<strong>at</strong><br />
transfer<br />
Solar he<strong>at</strong> gain<br />
G - value [%]<br />
- 2 -<br />
100 %<br />
90 %<br />
80 %<br />
70 %<br />
60 %<br />
50 %<br />
40 %<br />
30 %<br />
20 %<br />
10 %<br />
0 %<br />
Christof Erban, Schüco Intern<strong>at</strong>ional KG<br />
0 % 10 % 20 % 30 % 40 % 50 % 60 % 70 % 80 % 90 % 100 %<br />
Cell coverage [%]<br />
Figure 1: (a) Interaction of solar radi<strong>at</strong>ion and PV modules. (b) Total solar energy transmittance (g value) of<br />
semi-transparent PV elements vs. cell coverage for monolithic panels and insul<strong>at</strong>ing glazing<br />
Unfortun<strong>at</strong>ely, constant boundary conditions are assumed when the U or g value is determined<br />
experimentally or calcul<strong>at</strong>ed as described in the relevant standards. Especially the g value – describing<br />
the total solar gain through a component – is strongly affected by the reflectance, absorbance and<br />
transmittance of the component. As can be seen in Figures 2 and 3, these characteristics are for glass<br />
not constant for varying incident angles.<br />
1.0<br />
0.8<br />
0.6<br />
0.4<br />
0.2<br />
6 mm Flo<strong>at</strong> fg023066<br />
T 0° p-pol. (=s-pol.) calc.<br />
T 20° p-pol. calc.<br />
T 30° p-pol. calc.<br />
T 45° p-pol. calc.<br />
T 60° p-pol. calc.<br />
T 75° p-pol. calc.<br />
T p-pol. mess: 0°, 30°, 45°, 60°, 75°<br />
0.0<br />
300 400 500 600 700 800<br />
Wellenlänge [nm]<br />
0.0<br />
300 400 500 600 700 800<br />
Figure 2: Transmittance spectra of 6 mm flo<strong>at</strong> glass for p and s-polarized light and<br />
different angles of incidence [1]<br />
Tdd [-]<br />
1.0<br />
0.8<br />
0.6<br />
0.4<br />
0.2<br />
T 0° s-pol. (=p-pol.) calc.<br />
T 20° s-pol. calc.<br />
T 30° s-pol. calc.<br />
T 45° s-pol. calc.<br />
T 60° s-pol. calc.<br />
T 75° s-pol. calc.<br />
T s-pol. mess: 0°, 30°, 45°, 60°, 75°<br />
Wellenlänge [nm]
Change language