1. A house uses a gas heater, with 60 percent efficiency, for heating and an electric domestic water heater. The house annual heating load is 210 MMBTU. The average monthly electric consumption is 820 kWh (35 percent is for domestic water heating). The cost of gas is $1.0/therm and and that of electricity is $0.1/kWh. For an interest rate of 5 percent and 10 year EEM lifetime, select the best EEM option (compared to the existing condition) using LCC analysis. EEM 1: Replace the gas-burner ($520 cost) and replace the electric water heater with gas heater ($300 cost). Both 65 percent efficient. EEM 2: Replace the entire gas heater ($2,000 cost) and replace the electric water heater with tankless domestic water heater ($400 cost). Both 85 percent efficient. 1. A house uses a gas heater, with 60 percent efficiency, for heating and an electric domestic water heater. The house annual heating load is 210 MMBTU. The average monthly electric consumption is 820 kWh (35 percent is for domestic water heating). The cost of gas is $1.0/therm and and that of electricity is $0.1/kWh. For an interest rate of 5 percent and 10 year EEM lifetime, select the best EEM option (compared to the existing condition) using LCC analysis. EEM 1: Replace the gas-burner ($520 cost) and replace the electric water heater with gas heater ($300 cost). Both 65 percent efficient. EEM 2: Replace the entire gas heater ($2,000 cost) and replace the electric water heater with tankless domestic water heater ($400 cost). Both 85 percent efficient