Thermal Performance
Western Reflections Hurricane Impact Doorglass
can be used in doors to meet Energy Star criteria in the
Southern, South/Central, and North Central regions of the
United States (Door systems require NFRC testing). Thermal
performance values for different door systems are in the
table below.
NFRC thermal performance ratings are determined for a
fixed set of conditions and specs.
| Door system configuration with full glass |
U factor |
SHGC |
| Fiberglass door – polyurethane core |
0.39 |
0.22 |
| Steel door – wood edge – EPS core |
0.40 |
0.22 |
| Steel door – steel edge – EPS core |
0.46 |
0.22 |
Performance Criteria
The Energy Star® Windows Program is a voluntary
partnership between the Department of Energy (DOE) and
the fenestration industry (NFRC) to promote sales of energy
efficient windows, doors, and skylights. Regional thermal
performance standards as defined by DOE for 2005 are presented
below. Local and state codes are developed using Energy
Star standards as a guideline but may be more or less stringent.
| Climate Zone |
Max. U- factor |
MAX. SHGC |
| North |
0.35 |
Any |
| North/Central |
0.40 |
0.55 |
| South/Central |
0.40 |
0.40 |
| Southern |
0.65 |
0.40 |
U-Factor: Overall thermal
transmission. The lower the value, the slower the rate
of heat loss.
SHGC/Solar Heat Gain Coefficient: Portion
of directly transmitted and absorbed solar energy that
enters interior. The higher the value, the higher the heat
gain. |
