In a fire-tube boiler, hot products of combustion flowing through an array of thin-walled tubes are used to boil water flowing over the tubes. At the time of installation, the overall heat transfer coefficient was 400 W/m2 · K. After 1 year of use, the inner and outer tube surfaces are fouled, with corresponding fouling factors of R''f.i = 0.0015 and R''f.o = 0.0005 m2 · K/W, respectively. Should the boiler be scheduled for cleaning of the tube surfaces?