Description The UL5500 Pump is designed for use in 115-volt evaporative coolers rated up to 5,500 CFM of air delivery. It is UL classified for safety and features a low level design ensuring normal operation even if the coolerâs water level drops to as low as 1/2 in. The powerful 2 coil concentric motor pumps 245 GPH at a head height of 1 ft.