"U value" vs R rating on insulation

[davef]

I bought a 1993 14x70 Skyline built in Ohio(I live in western Pa). On the sticker sheet in the closet it lists the floors, walls, and roof in "U value" instead of the usual R value on insulation. I found out how to convert it to R value and comes out less than I expected. The walls are 4" so they would normally have R-14 insulation but comes out at roughly "R-11" instead. The roof was way less than expected as it shows to have "R-14" (R-25 and up is what I hear they should be). Floors are around "R-11" (which isn't a huge deal there).

My question is, are these U values based on just the insulation or the whole walls and ceilings itself, windows,doors,skylights included? Meaning for example, it could have R-14 in walls but with heat loss in windows and doors, it in effect brings it down to roughly the "R-11 range"?

[rmurray]

Hopefully a HAVC pro will chime in about he U vs R question...but I do know that usually 4 inch walls have R-11...There is some premium insulation at R-15 for 4 inch walls that few builders use.Some folks option 2x6 walls to hold R-19 insulation...R-11 is standard in the roof of most homes...Same for the floors..Most manufacturers also offer upgrades for both...

A good home inspector would have had this in his/her report...You can probably upgrade the roof insulation with little cost.....

[rmurray]

I thought I would use the wonders of the internet to find your answer....

coefficient of heat transmission (U-value)
--------------------------------------------------------------------------------

A value that describes the ability of a material to conduct heat. The number of BTU that flow through one square foot of material in one hour. It is the reciprocal of the R-value (i.e. U-value = 1/R-value). The lower the number, the greater the heat transfer resistance (insulating) characteristics of the material.

This site makes it clear that U value combines all materials in the wall or ceiling...

http://doityourself.com/windows/uvalue.htm

Another good explanation here..

http://www.irish-energy.ie/uploadedfile ... uvalue.pdf



The wall materials in your home combined equal a R-11 in the side walls.....There are many homes built standard with R-7 insulation..then the other materials will add more resistance to heat lose...Might be the case in your home..

A lot of energy lose is from air filtration..Air leaking out...Be sure all seals are tight. Look for sources of air leaks..often through the electric sockets and light switches...If they are leaking add seals that can be bought at a home improvement store...

[Eugene]

Dave,
your home was built BEFORE HUD changed the code to improve the insulation requirement (1994). Newer homes have more insulation.

[Stuart]

Eugene,

What did HUD change in 1994 regarding the insulation values?

Stu

[davef]

Thanks for the replys. Though sounds kinda sad that manufacturers had to use "bare bones" insulation before a new law came out "forcing" them to use the right kind.