Insulated Entry Doors R Value

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.

Insulated entry doors r value.

Rochester patina 1 2 lite unfinished smooth left hand fiberglass prehung front door with sidelites model 873190 3a4 139. Many of these doors are remarkably like real wood and may have a thick polyurethane or other foam core a feature that boosts their insulating value. Solid core wood entry doors have some insulating properties naturally inherent in wood. Look for a door with a good insulation value say a u value of at least 0 2 that is r 5 metric.

The r value of a 1 3 4 inch wood door is 3 03. In the chart above you will notice that there are two vastly different r values provided for insulated metal doors with polyurethane insulation. How wood doors stack up. 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.

Improved education and awareness of the cost of heating and cooling that escapes from poorly insulated components and glass panes have led to window and door manufacturers developing energy efficient windows and doors typically labeled r5 u 2 meaning the glass is the most energy efficient possible at a 5 rating and the window or door with all. The r values of most steel and fiberglass clad entry doors range from r 5 to r 6 excluding a window.