Heat is to be transferred from water to air through an aluminum wall. It is proposed to add rectangular fins 0.05-in. thick and 3/4-in. long spaced 0.08 in. apart to the aluminium surface to aid in transferring heat. The heat-transfer coefficients on the air and water sides are 3 and 25 Btu/h ft² °F, respectively. Evaluate the percent increase in heat transfer if these fins are added to (a) the air side, (b) the water side, (c) and both sides. What conclusions may be reached regarding this result?