A crossflow tower system is to be designed for the conditions: heat load $=4000$ MBtu hr $,$ tower approach $=15$ F$,$ cooling range $=20$ F$,$ wet$-$bulb temperature $=75$ F$.$ The fill is the Kelly$$s fill $($Type F$)$ with configuration: height $-36$ ft and depth $18$ ft$.$ The fans used in the tower system have a diameter of $28$ ft and an overall efficiency of $75\%.$ Determine the volume of tower fill and the fan brake horsepower. Don$$t forget to reference Appendix E$!$