PDFWAC 51-11C-404021
Table C404.2—Minimum performance of water-heating equipment.
Table C404.2
Minimum Performance of Water-Heating Equipment
Equipment Type | Size Category (input) | Subcategory or Rating Condition | Draw Pattern | Performance Requireda,j | Test Procedureb | |
Electric table-top water heatersk | ≤ 12 kWc | ≥ 20 gal ≤ 120 gal | Very small Low Medium High | UEF ≥ 0.6323 - (0.0058 × Vr) UEF ≥ 0.9188 - (0.0031 × Vr) UEF ≥ 0.9577 - (0.0023 × Vr) UEF ≥ 0.9884 - (0.0016 × Vr) | DOE 10 C.F.R. Part 430 App. E | |
Electric storage water heatersg,i resistance and heat pump | ≤ 12 kWc | ≥ 20 gal ≤ 55 gal | Very small Low Medium High | UEF ≥ 0.8808 - (0.0008 × Vr) UEF ≥ 0.9254 - (0.0003 × Vr) UEF ≥ 0.9307 - (0.0002 × Vr) UEF ≥ 0.9349 - (0.0001 × Vr) | DOE 10 C.F.R. Part 430 App. E | |
≤ 12 kW | ˃ 55 gal ≤ 120 gal | Very small Low Medium High | UEF ≥ 1.9236 - (0.0011 × Vr) UEF ≥ 2.0440 - (0.0011 × Vr) UEF ≥ 2.1171 - (0.0011 × Vr) UEF ≥ 2.2418 - (0.0011 × Vr) | DOE 10 C.F.R. Part 430 App. E | ||
Electric storage water heatersg | ˃ 12 kW | (0.3 + 27/Vm), %h | DOE 10 C.F.R. 431.106 App B. | |||
Grid-enabled water heatersg,l | ˃ 75 gal | Very small Low Medium High | UEF ≥ 1.0136 - (0.0028 × Vr) UEF ≥ 0.9984 - (0.0014 × Vr) UEF ≥ 0.9853 - (0.0010 × Vr) UEF ≥ 0.9720 - (0.0007 × Vr) | 10 C.F.R. 430 Appendix E | ||
Electric instantaneous water heaterh | ≤ 12 kW | < 2 gal | Very small Low Medium High | UEF ≥ 0.91 UEF ≥ 0.91 UEF ≥ 0.91 UEF ≥ 0.92 | DOE 10 C.F.R. Part 430 | |
˃ 12 kW & ≤ 58.6 kWc | ≤ 2 gal ≤ 180°F | All | UEF ≥ 0.80 | DOE 10 C.F.R. Part 430 | ||
Gas storage water heatersg | ≤ 75,000 Btu/h | ≥ 20 gal & ≤ 55 galf | Very small Low Medium High | UEF ≥ 0.3456 - (0.0020 × Vr) UEF ≥ 0.5982 - (0.0019 × Vr) UEF ≥ 0.6483 - (0.0017 × Vr) UEF ≥ 0.6920 - (0.0013 × Vr) | DOE 10 C.F.R. Part 430 App. E | |
≤ 75,000 Btu/h | ˃ 55 gal & ≤ 100 galf | Very small Low Medium High | UEF ≥ 0.6470 - (0.0006 × Vr) UEF ≥ 0.7689 - (0.0005 × Vr) UEF ≥ 0.7897 - (0.0004 × Vr) UEF ≥ 0.8072 - (0.0003 × Vr) | DOE 10 C.F.R. Part 430 App. E | ||
˃ 75,000 Btu/h and ≤ 105,000 Btu/hd | ≤ 120 gal ≤ 180°F | Very small Low Medium High | UEF ≥ 0.2674-0.0009 x Vr UEF ≥ 0.5362-0.0012 x Vr UEF ≥ 0.6002-0.0011 x Vr UEF ≥ 0.6597-0.0009 x Vr | DOE 10 C.F.R. Part 430 App. E | ||
˃ 105,000 Btu/hd,f | 80% Et SL ≤ (Q/800 +110√V), Btu/h | DOE 10 C.F.R. 431.106 | ||||
Gas instantaneous water heaterh | ˃ 50,000 Btu/h and < 200,000 Btu/h | < 2 gal | Very small Low Medium High | UEF ≥ 0.80 UEF ≥ 0.81 UEF ≥ 0.81 UEF ≥ 0.81 | DOE 10 C.F.R. Part 430 App. E | |
≥ 200,000 Btu/hd,f | < 10 gal | 80% Et | DOE 10 C.F.R. 431.106 | |||
≥ 200,000 Btu/hf | ≥ 10 gal | 80% Et SL ≤ (Q/800 +110√V), Btu/h | ||||
Oil storage water heatersg | ≤ 105,000 Btu/h | ≤ 50 gal | Very small Low Medium High | UEF = 0.2509 – (0.0012 × Vr) UEF = 0.5330 – (0.0016 × Vr) UEF = 0.6078 – (0.0016 × Vr) UEF = 0.6815 – (0.0014 × Vr) | DOE 10 C.F.R. Part 430 | |
˃ 105,000 Btu/h and ≤ 140,000 Btu/he | ≤ 120 gal ≤ 180°F | Very small Low Medium High | UEF ≥ 0.2932-0.0015 x Vr UEF ≥ 0.5596-0.0018 x Vr UEF ≥ 0.6194-0.0016 x Vr UEF ≥ 0.6740-0.0013 x Vr | DOE 10 C.F.R. Part 430 App. E | ||
˃ 140,000 Btu/h | 80% Et SL ≤ (Q/800 +110√V), Btu/h | DOE 10 C.F.R. 431.106 | ||||
Oil instantaneous water heaterh | ≤ 210,000 Btu/h | < 2 gal | 80% Et EF ≥ 0.59 - 0.0005 x V | DOE 10 C.F.R. Part 430 App. E | ||
˃ 210,000 Btu/h | < 10 gal | 80% Et | DOE 10 C.F.R. 431.106 | |||
˃ 210,000 Btu/h | ≥ 10 gal | 78% Et SL ≤ (Q/800 +110√V), Btu/h | DOE 10 C.F.R. 431.106 | |||
Hot water supply boilers, gas and oilh | ≥ 300,000 Btu/h and < 12,500,000 Btu/h | < 10 gal | 80% Et | DOE 10 C.F.R. 431.106 | ||
Hot water supply boilers, gash | ≥ 300,000 Btu/h and < 12,500,000 Btu/h | ≥ 10 gal | 80% Et SL ≤ (Q/800 +110√V), Btu/h | DOE 10 C.F.R. 431.106 | ||
Hot water supply boilers, oilh | ≥ 300,000 Btu/h and < 12,500,000 Btu/h | ≥ 10 gal | 78% Et SL ≤ (Q/800 +110√V), Btu/h | DOE 10 C.F.R. 431.106 | ||
Pool heaters, gas | All | 82% Et | DOE 10 C.F.R. Part 430 App. P | |||
Heat pump pool heaters | All | 50°F db 44.2°F wb outdoor air 80.0°F entering water | 4.0 COP | DOE 10 C.F.R. Part 430 App. P | ||
Unfired storage tanks | All | Minimum insulation requirement R-12.5 (h-ft2-°F)/Btu | (none) | |||
a | Thermal efficiency (Et) is a minimum requirement, while standby loss is a maximum requirement. In the standby loss equation, V is the rated volume in gallons and Q is the nameplate input rate in Btu/h. Vm is the measured volume in the tank in gallons. Standby loss for electric water heaters is in terms of %/h and denoted by the term "S," and standby loss for gas and oil water heaters is in terms of Btu/h and denoted by the term "SL" Draw pattern (DP) refers to the water draw profile in the Uniform Energy Factor (UEF) test. UEF and Energy Factor (EF) are minimum requirements. In the UEF standard equations, Vr refers to the rated volume in gallons. | |
b | Chapter 6 contains a complete specification, including the year version, of the referenced test procedure. | |
c | Electric instantaneous water heaters with input capacity ˃ 12 kW and ≤ 58.6 kW that have either (1) a storage volume ˃ 2 gal; or (2) is designed to provide outlet hot water at temperatures greater than 180°F; or (3) uses three-phase power has no efficiency standard. | |
d | Gas storage water heaters with input capacity ˃ 75,000 Btu/h and ≤ 105,000 Btu/h must comply with the requirements for the ˃ 105,000 Btu/h if the water heater either (1) has a storage volume ˃ 120 gal; (2) is designed to provide outlet hot water at temperatures greater than 180°F; or (3) uses three-phase power. | |
e | Oil storage water heaters with input capacity ˃ 105,000 Btu/h and ≤ 140,000 Btu/h must comply with the requirements for the ˃ 140,000 Btu/h if the water heater either (1) has a storage volume ˃ 120 gal; (2) is designed to provide outlet hot water at temperatures greater than 180°F; or (3) uses three-phase power. | |
f | Water heaters or gas pool heaters in this category are regulated as consumer products by the USDOE as defined in 10 C.F.R. Part 430. | |
g | Storage water heaters have a ratio of input capacity (Btu/h) to tank volume (gal) < 4000. | |
h | Instantaneous water heaters and hot water supply boilers have an input capacity (Btu/h) divided by storage volume (gal) ≥ 4000 Btu/h-gal. | |
i | There are no minimum efficiency requirements for electric heat pump water heaters greater than 12 kW or for gas heat pump water heaters. | |
j | Refer to Section C404.2.1 for additional requirements for service water heat system equipment. | |
k | A tabletop water heater is a storage water heater that is enclosed in a rectangular cabinet with a flat top surface not more than three feet (0.91 m) in height and have a ratio of input capacity (Btu/h) to tank volume (gal) < 4000. | |
l | 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." | ||
[Statutory Authority: RCW 19.27A.020, 19.27A.025, 19.27A.160 and chapters 19.27A and 19.27 RCW. WSR 22-14-091, 23-12-101, and 23-20-021, § 51-11C-404021, filed 7/1/22, 6/7/23, and 9/25/23, effective 3/15/24. Statutory Authority: RCW 19.27A.025, 19.27A.045 and chapter 19.27 RCW. WSR 20-21-080, § 51-11C-404021, filed 10/19/20, effective 2/1/21. Statutory Authority: RCW 19.27A.020, 19.27A.025, 19.27A.160 and chapter 19.27 RCW. WSR 19-24-040, § 51-11C-404021, filed 11/26/19, effective 7/1/20. Statutory Authority: RCW 19.27A.025, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-13-089, § 51-11C-404021, filed 6/15/16, effective 7/16/16. Statutory Authority: RCW 19.27A.025, 19.27A.160, and 19.27.074. WSR 16-03-072, § 51-11C-404021, filed 1/19/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.025 and chapters 19.27 and 34.05 RCW. WSR 13-04-056, § 51-11C-404021, filed 2/1/13, effective 7/1/13.]
Reviser's note: The brackets and enclosed material in the text of the above section occurred in the copy filed by the agency.