Chapter 14, Problem 43PE

Many decisions are made on the basis of the payback period: the time it will take through savings to equal the capital cost of an investment. Acceptable payback times depend upon the business or philosophy one has. (For some industries, a payback period is as small as two years.) Suppose you wish to install the extra insulation in Exercise 14.41. If energy cost $\$\text{1}.00$ per million joules and the insulation was $\$\text{4}.00$ per square meter, then calculate the simple payback time. Take the average $△T$ for the 120 day heating season to be $\text{15}.0°\text{C}$.