Water Heaters

What are the available types of water heaters and how do they work?

Conventional Tank-Style Water Heaters: Fueled by electricity, oil, natural gas, or propane.

• Tank-style water heaters not only heat the water they also store the water once it has been heated. This is why they are so large.
•  The capacity of a tank usually ranges from 30 to 80 gallons.
•  Non-electric, fuel-fired water heaters are equipped with a burner situated at the bottom of the tank. This allows the exhaust gases to travel through either the middle of the tank or around the outside of the tank to the exterior of the home.
• Tank-style electric water heaters have heating elements in the water that heat the water directly. Since there is no heat lost through the generation and venting of exhaust gases, tank-style electric water heaters are 80-90% efficient.

  

Tankless Water Heaters:  Fueled by electricity, oil, natural gas, or propane. Tankless water heaters are relatively small and are usually wall-mounted units that take up little space. They are, however, significantly more expensive to purchase and install than traditional tank-style units.

• When a hot water tap is turned on, the water heater senses the demand and ignites the burner or energizes the element. A larger element or burner will supply more hot water, which is convenient if two or more appliances require hot water simultaneously.
• The energy savings from eliminating the off-cycle costs (i.e. keeping an entire tank of water heated overnight) can be as much as 10-15%.

Encyclopedia of  Alternative Energy

Solar Water Heaters:  Fueled by the sun’s energy but are typically used to supplement standard fuel-fired or electric water heaters, since it is difficult to obtain sufficient energy from the sun to heat water to necessary temperatures on an ongoing basis. Solar water heaters are characterized either as open loop or closed loop systems.

• An open-loop system circulates household (potable) water through the solar panel, where the water is heated directly by the sun.

•  A closed-loop system uses a heat-transfer fluid to collect heat from the sun and a heat exchanger to transfer the heat from the heat-transfer fluid to household water.

Electric Hybrid Heaters:  More than twice as efficient as a standard electric water heater and easy to install, the Hybrid Electric Heat Pump water heater more than lives up to its impressive reputation. 

• Efficiency Mode. The most energy-efficient setting works by extracting warmth from the surrounding air, concentrating the heat and transferring it to the water.
• Hybrid Mode. This mode uses the heat pump for efficiency, but will use the element for quick recovery following increased hot water usage.
• Electric Mode. In this mode the unit operates as an electric water heater utilizing the elements only, for conditions when limited ambient heat is available.
• Vacation Mode. One touch operation maintains tank temperature at 60°F (15.6°C) during vacation or extended absence to reduce operating costs and provide freeze protection.