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Definitions for Column Headers- Heat Pump Water Heaters Product List

Brand and Model
This is how a particular water heater is identified. Manufacturers identify products they produce using the brand and model number. Some products may also be identified with a name or SKU, which is different from the brand or model number. You should always be able to find the brand and model number on a product.

Model numbers sometimes contain wildcard characters, such as *, #, and X, that are placeholders for non-energy attributes, such as color.

Volume is the capacity of the tank, in gallons.

Tank Height (inches)
Tank height is the distance from the bottom of the water heater�s tank to the top of its tank.

Tank Diameter (inches)
Tank diameter is the width or diameter of the water heater�s tank.

Input kW
Input kW refers to the input wattage of the heat pump or supplementary electric elements.

Volts refer to the potential of an outlet or circuit to provide electrical energy. The standard current in the typical U.S. home is in the range of 110 to 120 volts. However, circuits used for equipment, such as heat pump water heaters, may use voltage in the range of 220 to 240 volts. These heavy-duty circuits can be identified by their non-standard outlet plugs.

Energy Factor
Energy Factor is the ratio of useful energy output from the water heater to the total amount of energy delivered to the water heater. EF is a metric used to compare relative efficiencies of water heaters. The higher the EF is, the more efficient the water heater. EF is determined by the DOE test procedure, Code of Federal Regulations, Title 10, Section 430.

kWh/year refers to the amount of electricity consumed by the water heater according to its Energy Factor determined by the DOE test procedure, Code of Federal Regulations, Title 10, Section 430.

First Hour Rating (gallons per hour)
First-Hour Rating is the amount of hot water (in gallons) a storage water heater can supply per hour (starting with a tank full of hot water).

Min Warranty - Tank (years) and Min Warranty - Parts (years)
Warranty is an assurance by the manufacturing partner that the purchased equipment (tank) and components (parts) are warranted for a certain required period-of-time, depending on the technology. Minimum warranty is the shortest warranty you can receive on the qualified water heater model.

Models that appear in parenthesis and in red are discontinued by manufacturers, but may still be available in stores. Discontinued models will appear on this list for a year after their last production date to allow retailers to clear inventory. These models are still ENERGY STAR qualified, but they are no longer manufactured. Sponsors, such as utilities, may honor incentives for discontinued models at their discretion.