There are ten types of water coolers. Though these water coolers would look very similar like if they were sitting next to each other, they would also be very different. The Energy Star Cooler,while shopping for water coolers for the workplace I was surprised to learn that a typical unit uses a lot more energy than a full size refrigerator,that is why I specified that the cooler model must have an Energy Star label so it would use much less energy.Visit - www.puritanaqua.com