Equipment Type | Size Category (input) | Subcategory or Rating Condition | Performance Requireda, b | Test Procedure |
Storage water heaters, electric | ≤ 12 kWd | Tabletope ≥ 20 gal and ≥ 120 gal | 0.93 - 0.00132V, EF | DOE 10 C.F.R. Part 430 |
Resistance ≥ 20 gal and ≤ 55 gal | 0.960 - 0.0003V, EF | |||
Grid-enabledf ˃ 75 gal and ≤ 120 gal | 1.06 - 0.00168V, EF | |||
˃ 12 kWd | Resistance | (0.3 + 27)/Vm,%/hg | Section G.2 of ANSI Z21.10.3 | |
≤ 24 amps and ≤ 250 volts | Heat pump | 2.057 - 0.00113V, EF | DOE 10 C.F.R. Part 430 | |
Instantaneous water heaters, electric | All | Resistance | 0.93 - 0.00132V, EF | DOE 10 C.F.R. Part 430 |
Storage water heaters, gas | ≤ 75,000 Btu/h | ≥ 20 gal and ≤ 55 gal | 0.675 - 0.0015V, EF | DOE 10 C.F.R. Part 430 |
˃ 55 gal and ≤ 100 gal | 0.8012 - 0.00078V, EF | |||
˃ 75,000 Btu/h | < 4,000 Btu/h/gal | 80% Et (Q/800 + 110√V) SL, Btu/h | Section G.1 and G.2 of ANSI Z21.10.3 | |
˃ 50,000 Btu/h and < 200,000 Btu/h | ≥ 4,000 (Btu/h)/gal and < 2 gal | 0.82 - 0.0019V, EF | DOE 10 C.F.R. Part 430 | |
Instantaneous water heaters, gas | ≥ 200,000 Btu/hc | ≥ 4,000 Btu/h/gal and < 10 gal | 80% Et | Section G.1 and G.2 of ANSI Z21.10.3 |
≥ 200,000 Btu/h | ≥ 4,000 Btu/h/gal and ≥ 10 gal | 80% Et (Q/800 + 110√V) SL, Btu/h | ||
Storage water heaters, oil | ≤ 105,000 Btu/h | ≥ 20 gal | 0.68 - 0.0019V, EF | DOE 10 C.F.R. Part 430 |
˃ 105,000 Btu/h | < 4,000 Btu/h/gal | 80% Et (Q/800 + 110√V) SL, Btu/h | Section G.1 and G.2 of ANSI Z21.10.3 | |
≤ 210,000 Btu/h | ≥ 4,000 Btu/h/gal and < 2 gal | 0.59 - 0.0019V, EF | DOE 10 C.F.R. Part 430 | |
Instantaneous water heaters, oil | ˃ 210,000 Btu/h | ≥ 4,000 Btu/h/gal and < 10 gal | 80% Et | Section G.1 and G.2 of ANSI Z21.10.3 |
˃ 210,000 Btu/h | ≥ 4,000 Btu/h/gal and ≥ 10 gal | 78% Et (Q/800 + 110√V) SL, Btu/h | ||
Hot water supply boilers, gas and oil | ≥ 300,000 Btu/h and < 12,500,000 Btu/h | ≥ 4,000 Btu/h/gal and < 10 gal | 80% Et | Section G.1 and G.2 of ANSI Z21.10.3 |
Hot water supply boilers, gas | ≥ 300,000 Btu/h and < 12,500,000 Btu/h | ≥ 4,000 Btu/h/gal and ≥ 10 gal | 80% Et (Q/800 + 110√V) SL, Btu/h | |
Hot water supply boilers, oil | ≥ 300,000 Btu/h and < 12,500,000 Btu/h | ≥ 4,000 Btu/h/gal and ˃ 10 gal | 78% Et (Q/800 + 110√V) SL, Btu/h | |
Pool heaters, gas and oil | All | — | 82% Et | ASHRAE 146 |
Heat pump pool heaters | All | — | 4.0 COP | AHRI 146 |
Unfired storage tanks | All | — | Minimum insulation requirement R-12.5 (h • ft2 • °F)/Btu | (none) |
For SI: | °C = [(°F) - 32]/1.8, 1 British thermal unit per hour = 0.2931 W, 1 gallon = 3.785 L, 1 British thermal unit per hour per gallon = 0.078 W/L. |
a | Energy factor (EF) and thermal efficiency (Et) are minimum requirements. In the EF equation, V is the rated volume in gallons. |
b | Standby loss (SL) is the maximum Btu/h based on a nominal 70°F temperature difference between stored water and ambient requirements. In the SL equation, Q is the nameplate input rate in Btu/h. In the SL equation for electric water heaters, V is the rated volume in gallons and Vm is the measured volume in gallons. In the SL equation for oil and gas water heaters and boilers, V is the rated volume in gallons. |
c | Instantaneous water heaters with input rates below 200,000 Btu/h shall comply with these requirements if the water heater is designed to heat water to temperatures 180°F or higher. |
d | Electric water heaters with an input rating of 12 kW (40,950 Btu/h) or less that are designed to heat water to temperatures of 180°F or greater shall comply with the requirements for electric water heaters that have an input rating greater than 12 kW (40,950 Btu/h). |
e | A tabletop water heater is a water heater that is enclosed in a rectangular cabinet with a flat top surface not more than three feet (0.91 m) in height. |
f | A grid-enabled water heater is an electric resistance water heater that meets all of the following: |
1. Has a rated storage tank volume of more than 75 gallons. | |
2. Is manufactured on or after April 16, 2015. | |
3. Is equipped at the point of manufacture with an activation lock. | |
4. Bears a permanent label applied by the manufacturer that complies with all of the following: | |
4.1. Is made of material not adversely affected by water. | |
4.2. Is attached by means of nonwater soluble adhesive. | |
4.3. Advises purchasers and end-users of the intended and appropriate use of the product with the following notice printed in 16.5 point Arial narrow bold font: "IMPORTANT INFORMATION: This water heater is intended only for use as a part of an electric thermal storage or demand response program. It will not provide adequate hot water unless enrolled in such a program and activated by your utility company or another program operator. Confirm the availability of a program in your local area before purchasing or installing this product." | |
g | %/h is the energy consumed to replace the heat loss from the tank while on standby, expressed as a percentage of the total energy in the stored water per hour. |