What Window Glass Is Best?
There are basically 10 different types of window glass construction. Table 2 provides the percent of solar heat gain transmitted (SGHC) and the visible light transmitted (VT). These are important window glass considerations and are relative to where your home is located geographically.
Figure 2 - Garden window has extra window glass in order to provide additional visible light
Another example is where homeowners have a garden window, as shown in Figure 2, and would like to have as much visible light as possible on their plants.
Some window glass construction has advantages in geographic areas where heating is of prime concern while others have advantages when cooling is the primary energy expense.
As an example: In climates where heating is the primary concern, solar heat gain can save on energy costs. In climates where cooling is the primary concern, solar heat gain can be a major expense.
| Table 2 - Percent of Solar Heat Gain & Visible Light Transmitted For Different Window Glass Configurations | |||
Window Design |
Description |
Solar Heat Gain Transmitted (SGHC) |
Visible Light Transmitted (VT) |
|
Single pane of clear window glass |
86% |
90% |
|
Single pane of window glass with a bronze or silver tint |
73% |
68% |
|
Double panes of clear window glass |
76% |
81% |
|
Double panes of window glass with a bronze or silver tint |
63% |
61% |
|
Double panes of window glass with a high performance tint |
51% |
69% |
|
Double panes of window glass with high solar gain - Low-E and Argon or other inert gas. |
71% |
75% |
|
Double panes of window glass with medium solar gain - Low-E and Argon or other inert gas. |
58% |
78% |
|
Double panes of window glass with low solar gain - Low-E and Argon or other inert gas. |
39% |
71% |
|
Triple panes of window glass with high solar gain - Low-E and Argon or other inert gas. |
51% |
65% |
|
Triple panes of window glass with low solar gain - Low-E and Argon or other inert gas. |
33% |
56% |
