Home
  Available Modules
 
 
 
   
  Equipment
 

Storage Water Heaters

Storage water heaters, also known as tank water heaters, are the most common type in use for both residential and commercial applications. In fact, nearly half the commercial businesses use residential size water heaters.

On a lifecycle basis, gas-fired storage water heaters are typically the least expensive means of heating water. One reason is that per Btu, natural gas, as a primary energy source, is usually much less expensive than electricity. Natural gas water heaters typically provide hot water at costs less than one-half that of electric water heaters. Also, mass production of storage water heaters of 100-gallons or less make them less costly to manufacture than other types of water heaters.

The key differences between residential and commercial models are that commercial units have slightly larger volumes and much higher heat input rates than residential water heaters. Commercial water heaters have higher setpoint temperatures of 180oF compared to 140°F for residential water heaters. They also have larger pipe connections, more rugged controls and a few features only rarely found in residential models, such as electric flue dampers and electronic ignition.

Residential Gas Water Heater

 

Commercial Electric Water Heater

Multiple Water Heaters for Large Volume Users
Commercial applications may use two or more water heaters manifolded together (not all brands/models can adapt to this configuration). Parallel manifolding allows one or more of the water heaters to be shut down while the others operate; this gives uninterrupted hot water when a water heater needs service or replacement. For a facility that has widely varying levels of use, for example a stadium, such a system allows most of the water heating capacity to be shut off during periods when it won't be needed. Series manifolding, usually two tanks in series, is often used for facilities that need hot water at two different temperatures, for example, kitchens and laundries. The first tank provides hot water at about 120°F for general service, while the second tank heats some of the 120°F water to 180°F for dishwashers or high temperature washing machines.

Off-Peak Water Heaters
Commercial businesses that pay large electric demand charges or much lower rates during off-peak hours may use an off-peak water heater. These water heaters have very large tanks to store sufficient hot water for their on-peak downtime as well as controls that allow the electric elements to operate only during off-peak hours. Off-peak water heaters are usually only cost effective in areas where a large discount is offered for off-peak power.