Sectional Door Insulation Ratings

U-factor & R-value of Garage Door Insulation

The U-factor measures the rate at which heat is transferred through a material, such as a garage door. A lower U-factor indicates better insulation, meaning the residential garage or commercial sectional door will resist heat flow more effectively. The R-value evaluates the thermal resistance of a sectional door. It represents how well the door can impede the flow of heat. The higher the R-value, the greater the insulation capability of the door. U-factor is not the reciprocal for R-value for residential garage or commercial sectional doors. The biggest difference between R-value and U-factor ratings is how they are measured. R-value ratings are calculated mathematically by measuring a single section of a garage or commercial sectional door. U-factor ratings, on the other hand, are calculated by measuring the whole door system installed (the entire door, siding, framing, wall, materials used, etc.). This gives a more accurate thermal transference rating and as such, a more accurate picture of the thermal insulation efficiency.

Another reason for the move to U-factor, is that it is difficult to accurately measure the R-value of a section of a panel that is not completely flat(i.e. panels that have grooves or indentations cannot be accurately tested with R-value). U-factor gives a more accurate rating of the entire door, while R-value only measures a section of a single panel.

Is U-value the same as U-factor? U-value is used differently across the building and manufacturing industry, in some instances being introduced as the reciprocal of R-value. Only U-factor is used in the building codes for door and windows. Therefore, Overhead Door™ Brand will remove all U-value listings. This will remove any confusion regarding the meaning of U-value for the residential garage and commercial door industry and further emphasize the integrity of U-factor certified ratings.

Overhead Door Corporation Participates in the Door & Access Systems Manufacturing Association(DASMA) Thermal Performance Verification Program. The program verifies the thermal performance of residential sectional garage doors and commercial sectional doors

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What is the standard U-factor/R-value for a garage door?​​

Below is a list of our garage and commercial doors and the U-factor/R-value of each one.

*U-factor values are independently tested and verified per ANSI/DASMA 105.
**Overhead Door uses a calculated door section R-value for our insulated doors.