Performance Data
U-Value
A number which describes in specific terms, the ability of a material or assembly to transmit heat from outside to inside surfaces. Assemblies with lower U-values transmit less heat than those with higher values.
R-Value
A number which describes in specific terms, the ability of a material or assembly to insulate heat. Assemblies with higher R-values insulate more heat than those with lower values.
1 ÷ (U-Value) = R-Value
Solar Heat Gain Coefficient (SHGC)
A measure of how well a window absorbs or reflects heat from the sun. The lower the coefficient, the better the window is at blocking the sun's heat. Windows in hot or temperate climates should have a low SHGC; south-facing windows in cold climates should have a high SHGC.
To Determine the U-Value, R-Value or SHGC of your door simply follow the steps below:
- Determine which lite is installed in your door. Click on a product line to find your style: Classic-Craft, Fiber-Classic, Smooth-Star and Steel.
- Determine the lite's IG thickness and daylight opening size. Look for the following ranges noting the daylight opening:
| 1/4 Lite | 1/2 Lite | 3/4 Lite | Full Lite |
|---|
| ≤410 | ≤900 | ≤1100 | >1100 |
Click on a product line to find the dimensions of your lite: Classic-Craft, Fiber-Classic, Smooth-Star and Steel.
- Use the Fiberglass or Steel Door chart to match up the data collected in step two.
For your reference, please see the charts below for each product's specific U-Values and Solar Heat Gain Coefficients.
Energy Star Qualified Products
Energy Tax Credit Qualified Products
Sound Transmission Class (STC)
A measure representing how much noise is stopped by something. The higher the number the better: the scale is logarithmic, meaning each number is significantly higher than the next, like the Richter Scale for earthquake measurement.
STC Ratings & Reports
Design Pressure (DP)
Design Pressure (DP) ratings are based on a Therma-Tru door systems’ performance in Structural Load or Water Resistance and Air Infiltration tests. For example:
* DP50 structural performance rating indicates that the door system has passed a structural test pressure of 75 lbs. per. sq. ft which is equal to a 200 mph wind.
* DP50 water and air performance rating indicates that the door system has passed a water penetration test under conditions equal to 8” of rain per hour driven by 50 mph winds and an air infiltration test of 25 mph winds.
When the DP ratings are higher in number, the corresponding pressure, wind and water tests increase proportionately. DP ratings for Therma-Tru doors can be found by reviewing the evaluation reports found building codes here.
Performance Resources
Don't forget to check out all of our Energy Star qualified products and building codes section of the site for the latest product approvals and energy efficient products.