Calculate the rate of energy transfer for each of the substance.?

Question

Drywall,1.3cm(0.50in) R-value 0.45
Wood Shingles (overlapping) R-value 0.87
Flat glass 0.318cm(0.125in) R-value 0.89
Hardwood siding 2.54cm(1.00in) R-value 0.91
Vertical air space 8.9cm(3.5in) R-value 1.01
Insulating glass 0.64cm(0.25in) R-value 1.54
Cellulose fiber 2.54cm(1.00in) R-value 3.70
Brick 10.2cm(4.00in) R-value 4.00
Fiber glass batting 8.9cm(3.5in) R-value 10.90

Assume an area of 1.0m2(squared) and a temperaturedeffrence of 20.0 celsius

Answer 1

Since R is usually given as a total rather than a per in. or per cm. value, a 20°C differential with an area of 1 m^2 would result in the following heat flows (assuming SI units):

Drywall,1.3cm(0.50in) R-value 0.45 ==>≈ 44 W
Wood Shingles (overlapping) R-value 0.87 ==>≈ 23 W
Flat glass 0.318cm(0.125in) R-value 0.89 ==>≈ 22 W
Hardwood siding 2.54cm(1.00in) R-value 0.91 ==>≈ 22 W
Vertical air space 8.9cm(3.5in) R-value 1.01 ==>≈ 20 W
Insulating glass 0.64cm(0.25in) R-value 1.54 ==>≈ 13 W
Cellulose fiber 2.54cm(1.00in) R-value 3.70 ==>≈ 5.4 W
Brick 10.2cm(4.00in) R-value 4.00 ==>≈ 5.0 W
Fiber glass batting 8.9cm(3.5in) R-value 10.90 ==>≈ 1.8 W