U factor equation tables of building material r values.
R factor of 10 concrete wall.
The u factor is the heat transfer coefficient which simply means that is is a measure of an assembly s capacity to transfer thermal energy across its thickness.
U 1 r 1 14 2 0 070 btu hr f btu 0 4 w m k note that tables of precalculated r values and u factors including the various insulation and finish systems are available in thermal catalog of concrete masonry assemblies.
The u factor of an assembly is the reciprocal of the total r value of the assembly.
The values in table 2 are based on an ungrouted backup wythe.
The r values u factors listed in this tek were determined by calculation using the code recognized series parallel also called isothermal planes calculation method refs.
The insulation may be poured directly into walls or emptied into a simply wood or metal hopper which can be slid along the wall to direct the free flowing perlite into cores of cavities thus insulating all voids and air pockets.
The equation is shown below.
Wood frame walls 3 plus r value of the insulation used floors above unheated spaces 2 plus r value of the insulation used.
Concrete block walls u values r values.
A wall s thermal resistance or its r value is its ability to slow the transfer of heat from one side to the other.
8 thick concrete slab or foundation wall has an r value of about 1 04 30 while lightweight aggregate filled 8 thick concrete has an r value of about 2 18 30.
Cavity wall r values are listed in tek 6 1c r values of multi wythe concrete masonry walls ref.
By doubling the thickness of the wall to 16 inches the r value only increases by 0 50.
Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation.
R inch r thick ness insulation materials fiberglass batt 3 14 fiberglass blown attic 2 20 1 fiberglass blown wall 3 20 rock wool batt 3 14 rock wool blown attic 3 10 rock wool blown wall 3 03 cellulose blown attic 3 13 cellulose blown wall 3 70 vermiculite 2 13 air entrained concrete 3 90 urea terpolymer foam 4 48.
Typical residential weight concrete 8 wall r 2 5.
Concrete block makes a cost effective and structurally sound wall but it has.
Block thickness in inches.
2 x 4 wood stud wall 16 o c r 11 batts 1 2 plywood exterior 1 2 gypsum board interior.
The corresponding u factor for this wall is.
Concrete block walls 1 7 8 thick 15 2 15 7 103 7.
0 13 0 64 30.
