Estimate the fuel savings obtained by using low-leakage dampers for a 40,000-cfm AHU that serves an office building located in Chicago, Illinois. The office is conditioned during the entire heating season to 72°F (even during unoccupied hours). It was found that the existing dampers have 15 percent leakage when closed. The outdoor air damper system is scheduled to be closed 3,500 hours during the heating season. For the analysis, assume that the cost of fuel is $6/MMBtu and the boiler efficiency is 80 percent. The average heating season outdoor temperature in Chicago is 34.2 °F. The low-leakage dampers have a 1 percent leakage.