This project involves retrofitting the existing windows of the mansion with high-efficiency window film, weather-stripping, and new sashes, which will significantly reduce heat loss during the winter and improve cooling during the summer. The cost of this project is estimated at $20,000, with an annual energy cost savings of $1,100 per year. The useful life of this retrofitting is 25 years. Calculate the net present value (NPV), payback period, and internal rate of return (IRR) for the project, using an 8.25% required rate of return and a 20% tax rate for the university. Solve in excel with all steps explanation