High R Value Exterior Doors

The r value of a 1 3 4 inch wood door is 3 03.

High r value exterior doors.

Glass inserts also cut the door s insulating value though double or triple panel glass reduces that effect. R value measures how well certain building insulation materials can resist heat. European manufacturers of passivhaus certified doors advertise r values as high as r 11. Feather river doors 63 5 in x81 625in mission pointe zinc 3 4 oval lt unfinished smooth right hd fiberglass prehung front door w sidelights model 182191 3a4 70.

Most therma tru decorative as well as privacy and textured glass is triple pane for reduced heat flow. Therma tru fiberglass doors have a solid polyurethane foam core which is among the most energy efficient door materials available today. Know exactly how much you need with our project calculators. A polyurethane foam core.

Rustica s french style sliding barn doors entry doors and rustica s replacement windows have the most efficient r value on the market listed at 3 94 for interior doors and replacement windows and 5 31 for a 2 1 4 exterior door. Based on astm c518 calculation method the door has an r value of up to 11 but using astm c1363 tested operable the same door only have an r value of up to 3 5. The r values of most steel and fiberglass clad entry doors range from r 5 to r 6 excluding a window. For example a 1 1 2 inch 3 81 cm thick door without a window offers more than five times the insulating value of a solid wood door of the same size.

R values climb as thickness of the material increases. Rails and stiles these are the horizontal and vertical parts that brace a wood door. In new homes especially in cold climates in very energy efficient buildings look for the best performance doors possible. When determining how much insulation you need don t guesstimate calculate.

Look for a door with a good insulation value say a u value of at least 0 2 that is r 5 metric. Some of the features that help therma tru doors earn their energy star qualified ratings include. An insulated steel or fiberglass will have an r value that is twice as good generally r 5 to r 6 but in some cases as high as r 7.