solar heat gain control
One of the primary advantages of Kalwall over other types of glazing is its ability to control heat transfer without the need for special tints or coatings like vision glazing. This is accomplished by controlling both the transfer due to solar gain and due to conduction. The total heat gain that enters a building from the sun is known as solar heat gain. The measure of solar heat gain is called the Solar Heat gain Coefficient (SHGC) and is expressed as a decimal between 0 and 1. The lower the SHGC, the less solar gain is admitted into a building. Kalwall can provide a range of SHGCs suitable for a particular application and climate. In the example shown below a typical Kalwall panel (Crystal-White | 0.23 U-factor) is compared to a 1” clear insulated glass unit (IGU) to illustrate Kalwall’s inherent ability to manage solar heat gain while providing museum-quality daylighting™ along with superior thermal performance.
Solar Control Properties: Insulated Glass (IGU) vs Kalwall
Performance Data: 2-3/4” (70mm) Panel
| FRP Face Sheet Combinations | Visible Light Transmission (VLT) % | Solar Heat Gain Coefficient @ 0° | |||||||||
| Exterior FRP | Interior FRP | 0.53 U | 0.29 | 0.23 U | 0.22 | 0.14 U | 0.18 | 0.10 U | 0.05 U | 0.53 U | 0.29 | 0.23 U | 0.22 | 0.14 U | 0.18 | 0.10 U | 0.05 U |
| Crystal | White | 35% | 20% | 12% | 8% | 20% | 0.52 | 0.28 | 0.17 | 0.13 | 0.25 |
| White | White | 20% | 15% | 8% | 5% | 14% | 0.38 | 0.23 | 0.15 | 0.11 | 0.18 |
| Crystal | Crystal | 50% | 30% | 15% | 10% | N/A | 0.65 | 0.33 | 0.18 | 0.13 | N/A |
| Aqua | White | 29% | 17% | 6% | 4% | 15% | 0.45 | 0.24 | 0.14 | 0.1 | 0.21 |
| Rose | White | 30% | 18% | 6% | 4% | 16% | 0.46 | 0.24 | 0.15 | 0.1 | 0.21 |
| Ice Blue | White | 35% | 20% | 8% | 6% | 21% | 0.54 | 0.28 | 0.17 | 0.12 | 0.26 |
| Greenish Blue | Crystal | 25% | 14% | 5% | 3% | 14% | 0.5 | 0.23 | 0.14 | 0.1 | 0.19 |
Performance Data: 4” (100mm) Panel
| FRP Face Sheet Combinations | Visible Light Transmission (VLT) % | Solar Heat Gain Coefficient @ 0 | |||||||
| Exterior FRP | Interior FRP | 0.55 U | 0.15 U | 0.08 U | 0.05 U | 0.55 U | 0.15 U | 0.08 U | 0.05 U |
| Crystal | White | 35% | 14% | 7% | N/A | 0.52 | 0.09 | 0.04 | N/A |
| White | White | 20% | 12% | 5% | N/A | 0.38 | 0.06 | 0.04 | N/A |
| Crystal | Crystal | 50% | 17% | 8% | N/A | 0.65 | 0.10 | 0.07 | N/A |
| Air Gap Only | Fiberglass ‘Batts’ | Lumira® Aerogel |
U-value SI conversion: 1.0 W/m²K = 0.176 Btu/hr/ft²/°F
U-values shown in bold denote thermally-broken grid core panels.
Approximate Visible light transmission (VLT) values by ASTM E-972. VLT values over 30% are not recommended for most Kalwall applications.
Panel U-values include panel grid-core by NFRC 100 or 102. NFRC certified system U-values vary depending on framing.
Shading Coefficient (SC) is equal to 1.15 times the Solar Heat Gain Coefficient (SHGC).
