COD The R-value is a measure of how well insulating material resists the transfer of heat, such as the R- values of materials that builders use for the insulating walls and attics in houses (see figures): the higher the R-value the better it insulates. Fiberglass batt The fiberglass batt shown in the figure has an R-value of 19 (ft?hr F)/BTU (where BTU stands for British Thermal Unit: 1 BTU=1055 Joules). (a) Calculate the corresponding R-value in SI units (b) The R-value can then be used, for example, to calculate the rate of heat loss, Q. that a house wall hop Canvas XCOD (a) Calculate the corresponding R-value in Sl units (b) The R-value can then be used, for example, to calculate the rate of heat loss, Q, that a house wall loses to the environment knowing the area of the wall, A, and the temperature difference, (Tin-Tout), between the inside and the outside of the house. The following equation is used for this purpose: A (TI. Tot) Q R Calculate the rate of heat loss to the environment in J/hr, for a 15 fx8 ft-wall insulated with this batt when the inside temperature is 72 F and the outside temperature is 30 F (c) For a new small construction with a different type of insulation it was found that the rate of heat loss is given by the following dimensional equation: Q = 38.5. (Tin - Tout) where Q is in (BTU/min) and the temperatures are in F. Determine the units of 35.8 and convert this equation to a corresponding dimensional equation where Qis in Watts and Tinand Tout are in C