Storm Or Thermal Doors

In many buildings, doors are largely seen as unimportant or too small for consideration. However, the conduction and infiltration losses of doors are actually a substantial portion of the total energy and dollar losses in the building.

Infiltration losses can be minimized by adjusting door closers, improving weatherstripping, or installing vestibules. Reducing infiltration losses will have a significant impact on employee or customer comfort.

Minimizing conduction losses can be accomplished in several ways depending on the existing door types and the building aesthetics. Many commercial buildings have single pane glass doors. These can be improved by adding another pane of glass. If a glass door is not required for your business, an insulated metal door is a much better option. An existing wooden door can be improved by adding a storm door similar to those found in residential applications. If a storm door is unacceptable for aesthetic reasons, installing a new insulated metal door is the best option. Insulated metal doors have a core filled with either fiberglass or rigid foam insulation. They are more durable than glass or wood and provide better security. The table below lists the R-values for different type doors.

R-VALUES OF COMMON DOOR TYPES
Door Type
R-Value
Single Pane Glass
0.9
Double Pane Glass
2.0
Hollow Wood
2.0
Solid Wood
3.0
Hollow Metal
2.0
Insulated Metal
4.0-8.0

Overhead Doors

Because overhead doors cover a large area, improvements can have a noticeable impact. An existing overhead door which is not well insulated can be improved by adhering rigid insulation board or taping on fiberglass batts. Be sure local fire codes are not violated. Adding insulation to an existing door is inexpensive, but it usually does not hold up very well. A metal insulated door is the best solution for doors that need replacement.