Are tankless water heaters fueled by natural gas more energy efficient than their electric counterparts?
Natural gas-fueled tankless water heaters have efficiency factors as high as 83 percent. Coupled with an intermittent ignition device (rather than always-on autopilot), they require high amperage input when in use but easily compete with the electric models that run in the 95 percent efficiency range. The type that produces the least costly energy bill will depend upon the cost of fuel in your region. For more information, visit Chapter 4 of A Community Guide to Basic and Cost-Saving Construction in the American Southwest or Tankless Water Heater on the Technology Inventory.
