Question 3 [10 Marks] (a) A heat wheel can be installed on your exhaust air system to preheat the make up air. The installed cost is $150,000 and the unit has an economic life of 10yrs. How much does it save each year to return 15%. (2 Marks) (b) A desuperheater can be installed on your refrigeration system to obtain free hot water. You estimate that you can heat 570,000 litres of water per year from 15C to 60C. This will replace a natural gas heater that operates at 80% efficiency. You pay $40/GJ for your gas. The unit has an economic life of 5 yrs. How much can you pay for that unit and obtain a return of 12%. (8 Marks) 11 ( 2/5 167.16% NG * A PDF Question 3 [10 Marks] (a) A heat wheel can be installed on your exhaust air system to preheat the make up air. The installed cost is $150,000 and the unit has an economic life of 10yrs. How much does it save each year to return 15%. (2 Marks) (b) A desuperheater can be installed on your refrigeration system to obtain free hot water. You estimate that you can heat 570,000 litres of water per year from 15C to 60C. This will replace a natural gas heater that operates at 80% efficiency. You pay $40/GJ for your gas. The unit has an economic life of 5 yrs. How much can you pay for that unit and obtain a return of 12%. (8 Marks) 11 ( 2/5 167.16% NG * A PDF Question 3 [10 Marks] (a) A heat wheel can be installed on your exhaust air system to preheat the make up air. The installed cost is $150,000 and the unit has an economic life of 10yrs. How much does it save each year to return 15%. (2 Marks) (b) A desuperheater can be installed on your refrigeration system to obtain free hot water. You estimate that you can heat 570,000 litres of water per year from 15C to 60C. This will replace a natural gas heater that operates at 80% efficiency. You pay $40/GJ for your gas. The unit has an economic life of 5 yrs. How much can you pay for that unit and obtain a return of 12%. (8 Marks) 11 ( 2/5 167.16% NG * A PDF Question 3 [10 Marks] (a) A heat wheel can be installed on your exhaust air system to preheat the make up air. The installed cost is $150,000 and the unit has an economic life of 10yrs. How much does it save each year to return 15%. (2 Marks) (b) A desuperheater can be installed on your refrigeration system to obtain free hot water. You estimate that you can heat 570,000 litres of water per year from 15C to 60C. This will replace a natural gas heater that operates at 80% efficiency. You pay $40/GJ for your gas. The unit has an economic life of 5 yrs. How much can you pay for that unit and obtain a return of 12%. (8 Marks) 11 ( 2/5 167.16% NG * A PDF