How often do I need to refill ice?

Adding ice to the ice compartment gives the water an added chill, which then makes the breeze that much cooler. The ice will melt quite quickly, but the cooling effect within the water should last much longer. Depending on your environment’s heat and humidity, around 2 hours. Another robust option is to add ice to the water tank too, to really keep the coolness going. Just be sure there is ample water circulating through the pump system.