Thickness
Increasing the thickness of an insulating layer increases the thermal resistance. For example, doubling the thickness of fibreglass batting will double its R-value, perhaps from 2.0 m²K/W for 110 mm of thickness, up to 4.0 m²K/W for 220 mm of thickness. Heat transfer through an insulating layer is analogous to adding resistance to a series circuit with a fixed voltage. However, this only holds approximately because the effective thermal conductivity of some insulating materials depends on thickness. The addition of materials to enclose the insulation such as sheetrock and siding provides additional but typically much smaller R-value.
Read more about this topic: R-value (insulation)
Famous quotes containing the word thickness:
“For his teeth seem for laughing round an apple.
There lurk no claws behind his fingers supple;
And God will grow no talons at his heels,
Nor antlers through the thickness of his curls.”
—Wilfred Owen (1893–1918)