Using information developed in Problem 1-42, investigate the energy cost saving that results from the installation of a layer of glass wool 15 cm thick on a steel building 12 by 12 m in size and 5 m high. Assume the building is subjected to a temperature difference of 30ºC and the floor of the building does not participate in the heat lost. Assume that the outer surface of the building loses heat by convection to a surrounding temperature of −10ºC with a convection coefficient h = 13 W/m2 · ºC.
Problem 1-42
In energy conservation studies, cost is usually expressed in terms of Btu of energy, or some English unit of measure such as the gallon. Some typical examples are
Overall cost: $/106 Btu
Transportation results: passenger miles per 106 Btu or per gallon of fuel
ton-miles of freight per 106 Btu or per gallon of fuel
Consult whatever sources are needed, and devise suitable measures for energy consumption and cost using the SI system of units. How would you price such items as
Energy content of various types of coal
Energy content of gasoline
Energy content of natural gas
Energy "content" of electricity
After devising the SI system of cost measures, construct a table of conversion factors like that given in the front inside cover of this book, to convert from SI to English and from English to SI.