An air conditioner includes an airflow path configured to direct an airflow in a direction. The air conditioner also includes an evaporative cooling membrane panel disposed within the air flow path and including a face disposed at an oblique angle relative to the direction. The face is defined by microporous fibers of the evaporative cooling membrane panel. Each microporous fiber is configured to receive liquid in a fluid flow path of the microporous fiber such that the air flow over the microporous fiber generates a vapor. Each microporous fiber is also configured to release the vapor into the air flow via pores of the microporous fiber.