High R Value Exterior Doors

Rails and stiles these are the horizontal and vertical parts that brace a wood door.

High r value exterior doors.

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. Glass inserts also cut the door s insulating value though double or triple panel glass reduces that effect. This is a huge difference and essentially comes down to astm c518 being a theoretical maximum based on a steady state thermal test of only a portion of the door panel. Therma tru fiberglass doors have a solid polyurethane foam core which is among the most energy efficient door materials available today.

Some of the features that help therma tru doors earn their energy star qualified ratings include. The higher the r value the greater the insulation performance. 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. 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.

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. A 2 1 4 inch solid core wooden door for example has an r value of 3 70. 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.

Know exactly how much you need with our project calculators. A polyurethane foam core. The r values of most steel and fiberglass clad entry doors range from r 5 to r 6 excluding a window. R values climb as thickness of the material increases.

Most therma tru decorative as well as privacy and textured glass is triple pane for reduced heat flow. 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. In new homes especially in cold climates in very energy efficient buildings look for the best performance doors possible.