Blown Cellulose Fiber Thermal Insulations: Part 2—Thermal Resistance

The thermal resistance of a number of commercial blown loose-fill cellulose fiber thermal insulations has been measured using the guarded hot plate and heat flowmeter methods. An equation describing the variation of thermal resistance with temperature, temperature difference, density, and thickness has been derived from these measurements and, with lesser precision, from the data provided by other investigators. The equation does not include the effects of chemical content, moisture content, chemical composition, or structure of the paper particles. The thermal resistance of a layer of insulation was found not to be directly proportional to thickness. The equation for thermal resistance fits the National Research Council of Canada (NRC) data with a standard deviation of less than 3.5 percent for thickness of 50 to 305 mm.