In the Know: High-Efficiency vs. Standard-Efficiency Water Heaters
Tankless water heaters can offer the highest efficiency potential, but they are more conducive to personal or private use and therefore are generally not considered very efficient in commercial applications.
This article is focused on tank-type water heaters – also called storage water heaters, these classic cylindrical tanks both heat and store the water, keeping it continuously hot and ready for use. Hot water is produced by burning fuel such as natural gas or propane, or using electricity, to generate the heat used to raise the water temperature.
Natural gas water heaters are still the most common, probably because they are generally more efficient than electric water heaters. Gas water heaters can heat the water to set temperature about twice as fast as electric heaters do, and cost about half as much to run as an electric unit.
