2. A 50-hp constant volume fan is to be retrofitted to a variable volume fan. Three options are considered: outlet dampers at a cost of $3,100, inlet vanes fan at a cost of $6,950, and variable speed drive at a cost of $8,500. The table provides data for fan power, load profile, and fan operating time. If the fan is operated 5,500 hours per year, and the cost of electricity is $0.08/kWh, determine the best option for retrofitting the constant volume fan. Fan Power (%) Operating Time (%) Load (%) Outlet Dampers Inlet Vanes VSD Option Option II 100 100 100 100 5 20 98 89 82 90 5 30 96 78 64 80 10 25 92 70 50 70 15 20 88 61 36 60 25 5 83 56 26 50 20 o 77 51 16 40 20 0 2. A 50-hp constant volume fan is to be retrofitted to a variable volume fan. Three options are considered: outlet dampers at a cost of $3,100, inlet vanes fan at a cost of $6,950, and variable speed drive at a cost of $8,500. The table provides data for fan power, load profile, and fan operating time. If the fan is operated 5,500 hours per year, and the cost of electricity is $0.08/kWh, determine the best option for retrofitting the constant volume fan. Fan Power (%) Operating Time (%) Load (%) Outlet Dampers Inlet Vanes VSD Option Option II 100 100 100 100 5 20 98 89 82 90 5 30 96 78 64 80 10 25 92 70 50 70 15 20 88 61 36 60 25 5 83 56 26 50 20 o 77 51 16 40 20 0