The standards on residential water heater efficiency, which are required by Congress, have not been updated in 13 years. Water heating is responsible for roughly 13% of both annual residential energy use and consumer utility costs, the DOE said.

  • @schroedingershat
    link
    21 year ago

    Storage water heaters can also capture off peak or curtailed energy (acting as 6-12kWh of diurnal storage), so they are more than 3x better in terms of emissions.