Five years ago, ARCHON, a regional architecture/contractor firm, purchased an HVAC unit for \($25,000\) that was expected to last 15 years. It will have a salvage value of \($0\) in 10 more years. The annual operating cost of this unit started at \($2,000\) in the first year and has increased steadily at \($250\) per year ever since; last year the cost was \($3,000.\) Its book value is now \($13,000.\) ARCHON has been phenomenally successful due to their reputation for highly functional, high-quality, cost-effective designs and construction. They are building a new wing at their regional headquarters to accommodate a much larger computer design emphasis requiring larger, faster computers, architectural printers, e-storage for a construction repository of previous designs, and an increased human heat load. They can buy an additional unit to air-condition the new wing for \($18,000.\) It will have a service life of 15 years, a net salvage of \($0\) at that time, and a \($3,000\) market value after 10 years. It will have annual operating costs of \($1,800\) in the first year, increasing at \($100\) per year. As an alternative, ARCHON can buy a new unit to heat and cool the entire building for \($35,000.\) It will last for 15 years and have a net salvage of \($0\) at that time; however, it will have a market value of \($8,500\) after 10 years. It will have first-year operating costs of \($3,700/year,\) increasing at \($200\) per year. The present unit can be sold now for \($7,000.\) MARR is 20 percent, and the planning horizon is 10 years.

a. Clearly show the cash flow profile for each alternative using a cash flow approach (insider’s viewpoint approach). 

b. Using a PW analysis and a cash flow approach (insider’s viewpoint approach), decide which is the more favorable alternative.

c. Clearly show the cash flow profile for each alternative using an opportunity cost approach (outsider’s viewpoint approach). 

d. Using a PW analysis and an opportunity cost approach (outsider’s viewpoint approach), decide which is the more favorable alternative.