Description The UL5000 Offset Pump is designed for use in small to medium, 115-Volt evaporative coolers rated up to 5,000 CFM of air delivery. It is UL classified for safety and features a low-level design ensuring normal operation even if the cooler's water level drops to as low as 1/2 in. The single-coil motor design will pump 225 Gal. per hour at a head height of 1 ft.