An evaporative cooling unit includes a first V-shaped portion of a winding of microporous hollow fibers configured to receive a liquid. The evaporative cooling unit also includes a second V-shaped portion of the winding of microporous hollow fibers configured to receive the liquid, where the second V-shaped portion is coupled with the first V-shaped portion. The evaporative cooling unit also includes an internal cavity disposed between the first V-shaped portion and the second V-shaped portion.