R Value Of Glass Doors

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 of it s built out components are a 2 which is almost as low as any rating can go remember a 5 is the highest energy rating for r value which is.

R value of glass doors.

Exterior doors excluding sliding glass doors calculate glass area of door as window wood door r value 1 1 2 no storm door 2 7 1 1 2 with 1 storm door 4 3 1 2 3 solid core door 3 1 steel with foam core door r value 1 3 4 pella 13 3 4 therma tru 16 roof ceiling material r value no insulation 3 3 3 1 2 fiberglass 13. There are many websites on the internet which have imperial building material r value numbers but not so many with metric r value numbers. Overhead door corporation uses a calculated door section r value for our insulated doors. When determining how much insulation you need don t guesstimate calculate.

The lower the u value the better the insulating ability. 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. Actively cooled or heated garages should have a garage door with an r value of r 13 or higher to save on energy costs. The following table is in metric form.

So the reciprocal of your glass unit s u value of 0 29 can be determined by dividing the number 1 by 0 29 which would give us 3 4482 or roughly 3 5 and that would be the r value for your glass. Know exactly how much you need with our project calculators. Detached garages need a lower overall r value between 0 and r 6. If installed correctly and not bent this type of door needs no further weatherstripping.

What is a good r value for a garage door. R value measures how well certain building insulation materials can resist heat. Attached but not actively heated or cooled garages should have a garage door with an r value between r 6 and r 9. Click here to go to our calculator to understand the real r value of a ceiling system or wall system with gaps in the insulation.

The higher the r value the greater the insulation performance. In the chart above you will notice that there are two vastly different r values provided for insulated metal doors with polyurethane insulation. The r values of most steel and fiberglass clad entry doors range from r 5 to r 6 excluding a window.