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Residential Water Heaters Key Product Criteria
| ENERGY STAR Residential Water Heaters — Eligible Product Types | |
|---|---|
| High-Efficiency Gas Storage | A nominal input of 75,000 BTU/hour or less and a rated storage volume from 20 to 100 gallons. |
| Gas Condensing | |
| Heat Pump Water Heaters | A maximum current rating of 24 amperes, voltage no greater than 250 volts, and a transfer of thermal energy from one temperature to a higher temperature level for the purpose of heating water. Unit must have "integrated" or "drop-in" configuration. |
| Whole-Home Gas Tankless | A nominal input of over 50,000 BTU/hour up to 200,000 BTU/hour and a rated storage volume of 2 gallons or less. |
| Solar Water Heaters | OG-300 rating from the SRCC. Auxiliary tank must be residential-class. |
ENERGY STAR Criteria
A water heater model must meet all of the identified criteria to be labeled as ENERGY STAR.
High-Efficiency Gas Storage
| ENERGY STAR Criteria | Energy Factor | First-Hour Rating | Warranty | Safety |
|---|---|---|---|---|
| Gas Storage (Ending 8/31/2010) |
EF ≥ 0.62 | FHR ≥ 67 gallons per hour | Warranty ≥ 6 years on sealed system | ANSI Z21.10.1/CSA 4.1 |
| Gas Storage (Beginning 9/1/2010) |
EF ≥ 0.67 | FHR ≥ 67 gallons per hour | Warranty ≥ 6 years on sealed system | ANSI Z21.10.1/CSA 4.1 |
Gas Condensing
| ENERGY STAR Criteria | Energy Factor | First-Hour Rating | Warranty | Safety |
|---|---|---|---|---|
| Gas Condensing | EF ≥ 0.8 | FHR ≥ 67 gallons per hour | Warranty ≥ 8 years on sealed system | ANSI Z21.10.1/CSA 4.1 |
Heat Pump Water Heaters
| ENERGY STAR Criteria | Energy Factor | First-Hour Rating | Warranty | Safety |
|---|---|---|---|---|
| Heat Pump Water Heaters | EF ≥ 2.0 | FHR ≥ 50 gallons per hour | Warranty ≥ 6 years on sealed system | UL 174 & UL 1995 |
Whole-Home Gas Tankless
| ENERGY STAR Criteria | Energy Factor | Gallons-Per-Minute | Warranty | Safety |
|---|---|---|---|---|
| Whole-Home Gas Tankless | EF ≥ 0.82 | GPM ≥ 2.5 over a 77°F rise | Warranty ≥ 10 years on heat exchanger and 5 years on parts | ANSI Z21.10.3/CSA 4.3 |
Solar Water Heaters
| ENERGY STAR Criteria | Solar Fraction | Warranty | Safety |
|---|---|---|---|
| Solar Water Heaters | SF ≥ 0.5 | Warranty ≥ 10 years on solar collector, 6 years on storage tank, 2 years on controls and 1 year for piping and parts | OG-300 Certification from the SRCC |
Glossary
Energy Factor (EF): Energy Factor is the ratio of useful energy output from the water heater to the total amount of energy delivered to the water heater. The higher the EF is, the more efficient the water heater.
Solar Fraction (SF): Solar Fraction is the portion of the total conventional hot water heating load (delivered energy and tank standby losses) provided by solar energy. The higher the SF is, the more efficient the solar water heater.
First-Hour Rating (FHR): 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).
Gallons per Minute (GPM): Gallons per Minute is the amount of hot water in gallons a tankless water heater can supply per minute over a 77°F temperature rise.
Temperature Rise: The difference between the temperature of the hot water exiting the heater and the cold water entering the heater. If you want a shower of 110°F and you live in south Florida with groundwater at 70°F, then that is a 40°F temperature rise (110-70=40).
