2006-11-30 10:07:41 · 5 answers · asked by lucinda_mackenzie 1 in Science & Mathematics ➔ Other - Science
AIR, WOOD, stone, (insulation)
R-value
The R-value of a material is its resistance to heat flow and is an indication of its ability to insulate. It is used as a standard way of telling how good a material will insulate.The higher the R-value, the better the insulation.
Definition
The R-value is the reciprocal of the amount of heat energy per area of material per degree difference between the outside and inside. Its units of measurement for R-value are:
(square feet x hour x degree F)/BTU in the English system and
(square meters x degrees C)/watts in the metric system
Material
R-value
Hardwood siding (1 in. thick)
0.91
Wood shingles (lapped)
0.87
Brick (4 in. thick)
4.00
Concrete block (filled cores)
1.93
Fiberglass batting (3.5 in. thick)
10.90
Fiberglass batting (6 in. thick)
18.80
Fiberglass board (1 in. thick)
4.35
Cellulose fiber (1 in. thick)
3.70
Flat glass (0.125 in thick)
0.89
Insulating glass (0.25 in space)
1.54
Air space (3.5 in. thick)
1.01
Free stagnant air layer
0.17
Drywall (0.5 in. thick)
0.45
Sheathing (0.5 in. thick)
1.32
2006-11-30 10:16:42 · answer #1 · answered by MaryinRed12 2 · 0⤊ 0⤋
wood, glass, cinderblocks used to make foundations for homes.
all are poor conductors of heat and are slow to heat, depending on the thickness of the material.
2006-11-30 21:09:31 · answer #2 · answered by bandit200129715 1 · 0⤊ 0⤋
Air
Wood
Ice
2006-11-30 18:15:34 · answer #3 · answered by Anonymous · 0⤊ 0⤋
1 used to be the now banned asbestos!
2006-11-30 18:30:50 · answer #4 · answered by Anonymous · 0⤊ 0⤋
air, wood, drywall
2006-11-30 18:23:01 · answer #5 · answered by ROSS S 1 · 0⤊ 0⤋