Intellihot introduces the Electron tankless heat pump water heaters, the first such technology for commercial applications, the company says. The Electron combines the efficiency of heat pump technology, the water safety and on-demand features of tankless, with the compliance of CO2 refrigerant paired with a specially designed thermal battery. Models include the iE1, an integrated unit with a thermal battery that can be installed indoors or outdoors; and the iE6, a larger unit that installs outdoors and pairs with the iB3, an indoor thermal battery.