(a) Each commercial storage water heater, instantaneous water heater, and hot water supply boiler (excluding residential-duty commercial water heaters) must meet the applicable energy conservation standard level(s) as specified in the table to this paragraph. Any packaged boiler that provides service water that meets the definition of “commercial packaged boiler” in subpart E of this part, but does not meet the definition of “hot water supply boiler” in subpart G of this part, must meet the requirements that apply to it under subpart E of this part.
Table 1 to § 431.110(a)—Commercial Water Heater Energy Conservation Standards
| Equipment
| Size
| Energy conservation standards
a
|
|---|
Minimum thermal
efficiency
(equipment
manufactured on
and after October 9, 2015)
(%)
| Minimum thermal
efficiency
(equipment
manufactured on
and after October 6, 2026)
(%)
| Maximum standby loss
(equipment manufactured on
and after October 29, 2003)
b
| Maximum standby loss
(equipment manufactured on
and after October 6, 2026)
b
|
|---|
| Electric storage water heaters | All | N/A | N/A | 0.30 + 27/Vm (%/h) | 0.30 + 27/Vm (%/h)
|
| Gas-fired storage water heaters and storage-type instantaneous water heaters | All | 80 | 95 | Q/800 + 110(Vr)
1/2 (Btu/h) | 0.86 × [Q/800 + 110(Vr)
1/2] (Btu/h)
|
| Oil-fired storage water heaters | All | 80 | 80 | Q/800 + 110(Vr)
1/2 (Btu/h) | Q/800 + 110(Vr)
1/2 (Btu/h)
|
| Electric instantaneous water heaters
c | <10 gal
≥10 gal | 80
77 | 80
77 | N/A
2.30 + 67/Vm (%/h) | N/A
2.30 + 67/Vm (%/h)
|
| Gas-fired instantaneous water heaters and hot water supply boilers | <10 gal
≥10 gal | 80
80 | 96
96 | N/A
Q/800 + 110(Vr)
1/2 (Btu/h) | N/A
Q/800 + 110(Vr)
1/2 (Btu/h)
|
| Oil-fired instantaneous water heater and hot water supply boilers | <10 gal
≥10 gal | 80
78 | 80
78 | N/A
Q/800 + 110(Vr)
1/2 (Btu/h) | N/A
Q/800 + 110(Vr)
1/2 (Btu/h)
|
(b) Each unfired hot water storage tank manufactured on and after October 29, 2003, must have a minimum thermal insulation of R-12.5.
(c) Each residential-duty commercial water heater must meet the applicable energy conservation standard level(s) as follows:
Table 2 to § 431.110(c)—Residential-Duty Commercial Water Heater Energy Conservation Standards
| Equipment
| Specifications
a
| Draw pattern
| Uniform energy factor
b
|
|---|
| Equipment manufactured before October 6, 2026
| Equipment manufactured after October 6, 2026
|
|---|
| Gas-fired storage | >75 kBtu/hr and ≤105 kBtu/hr and ≤120 gal | Very Small
Low
Medium
High | 0.2674−(0.0009 × Vr)
0.5362−(0.0012 × Vr)
0.6002−(0.0011 × Vr)
0.6597−(0.0009 × Vr) | 0.5374−(0.0009 × Vr)
0.8062−(0.0012 × Vr)
0.8702−(0.0011 × Vr)
0.9297−(0.0009 × Vr)
|
| Oil-fired storage | >105 kBtu/hr and ≤140 kBtu/hr and ≤120 gal | Very Small
Low
Medium
High | 0.2932−(0.0015 × Vr)
0.5596−(0.0018 × Vr)
0.6194−(0.0016 × Vr)
0.6470−(0.0013 × Vr) | 0.2932−(0.0015 × Vr)
0.5596−(0.0018 × Vr)
0.6194−(0.0016 × Vr)
0.6470−(0.0013 × Vr)
|
| Electric instantaneous | >12 kW and ≤58.6 kW and ≤2 gal | Very Small
Low
Medium
High | 0.80
0.80
0.80
0.80 | 0.80
0.80
0.80
0.80
|