ZEMCH 2019 International Conference Proceedings April.2020 | Page 174
Table 1. Glazing systems for double windows
Glazing system
A
B
C
D
E
F
Composition
5CL + 12Air + 5CL
5CL + 12Air + 5LE
5CL + 0.76PVB + 3CL + 12Air + 5LE
5CL + 12Air + 5LE
5LE + 12Ar + 5LE
6LE + 14Ar + 5CL
Ug (W∙m ‐2 ∙K ‐1 )
2.901
1.704
1.664
1.624
1.278
1.124
Table 2 indicates the seven double window cases according to the product name and the glazing
system. In this study, four double window products are chosen, which are widely used in the Korean
market; these have an internal window that slides. Product name VBF250 has an external window that
consists of an upper component that slides and a lower component that is fixed. The others have
internal and external windows that slide, which are common in Korea. Each type of double window
has a different frame profile, so these can have different distances between the external and internal
windows. S3‐235 and S5‐250 have the same distance (88 mm), while HS235D has a 94 mm distance.
VBF250 has a different upper and lower component in the external window, so it has a 70.6 mm distance
in the upper part and a 94.5 mm distance in the lower part. Cases 1 and 2 are the same type of double
window with two different glazing systems and so are Cases 3 and 4. Cases 6 and 7 are based on VBF250,
and the upper part of the external window and the internal window have glazing systems A or B in
each case, but the lower part of the external window is not changed.
2.2. Laboratory tests
Laboratory tests of all the double window cases are carried out according to KS F 2278. Specimens
of 2.0 m × 2.0 m in size are installed onto an attachment frame which is fixed between the cold chamber
and hot chamber of the experimental apparatus. A previous study [8] explains how to evaluate the
thermal performance of a double window in an experimental test. In this study, the thermal
transmittances of seven cases are tested by the same procedure used therein, and these values are
compared to the thermal transmittance values that are calculated and certified by international
standards.
Table 2. Specification on the double window cases
Case
1
Product name
of the window
2
3
4
5
163
Glazing system
External
window Internal
window Distance between the external
and internal
windows [mm]
A D 88
E E 88
A D 88
A A 88
F F 94
ZEMCH 2019 International Conference l Seoul, Korea