10 CFR 431.110 - Energy conservation standards and their effective dates.

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§ 431.110 Energy conservation standards and their effective dates.

Each commercial storage water heater, instantaneous water heater, unfired hot water storage tank and hot water supply boiler 1 must meet the applicable energy conservation standard level(s) as follows:

1 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, must meet the requirements that apply to it under subpart E.

Equipment category Size Energy conservation standard a
Maximum standby loss c (equipment manufactured on and after October 29, 2003) b Minimum thermal efficiency (equipment manufactured on and after October 29, 2003 and before October 9, 2015) b Minimum thermal efficiency (equipment manufactured on and after October 9, 2015) b
Electric storage water heaters All 0.30 27/Vm (%/hr) N/A N/A
Gas-fired storage water heaters ≤155,000 Btu/hr Q/800 110(Vr)½ (Btu/hr) 80% 80%
>155,000 Btu/hr Q/800 110(Vr)½ (Btu/hr) 80% 80%
Oil-fired storage water heaters ≤155,000 Btu/hr Q/800 110(Vr)½ (Btu/hr) 78% 80%
>155,000 Btu/hr Q/800 110(Vr)½ (Btu/hr) 78% 80%
Gas-fired instantaneous water heaters and hot water supply boilers <10 gal N/A 80% 80%
≥10 gal Q/800 110(Vr)½ (Btu/hr) 80% 80%
Oil-fired instantaneous water heaters and hot water supply boilers <10 gal N/A 80% 80%
≥10 gal Q/800 110(Vr)½ (Btu/hr) 78% 78%
Equipment Category Size Minimum thermal insulation
Unfired hot water storage tank All R-12.5

aVm is the measured storage volume, and Vr is the rated volume, both in gallons. Q is the nameplate input rate in Btu/hr.

b For hot water supply boilers with a capacity of less than 10 gallons: (1) The standards are mandatory for products manufactured on and after October 21, 2005, and (2) products manufactured prior to that date, and on or after October 23, 2003, must meet either the standards listed in this table or the applicable standards in subpart E of this part for a “commercial packaged boiler.”

c Water heaters and hot water supply boilers having more than 140 gallons of storage capacity need not meet the standby loss requirement if: (1) The tank surface area is thermally insulated to R-12.5 or more; (2) a standing pilot light is not used; and (3) for gas or oil-fired storage water heaters, they have a fire damper or fan assisted combustion.

[69 FR 61983, Oct. 21, 2004; 69 FR 63574, Nov. 2, 2004, as amended at 80 FR 42667, July 17, 2015]

Title 10 published on 2015-01-01

The following are ALL rules, proposed rules, and notices (chronologically) published in the Federal Register relating to 10 CFR Part 431 after this date.

  • 2015-12-09; vol. 80 # 236 - Wednesday, December 9, 2015
    1. 80 FR 76355 - Energy Conservation Program: Energy Conservation Standards for High-Intensity Discharge Lamps
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      DEPARTMENT OF ENERGY, Office of Energy Efficiency and Renewable Energy
      Final determination.
      This final determination is effective December 9, 2015.
      10 CFR Part 431