10 CFR 431.106 - Uniform test method for the measurement of energy efficiency of commercial water heaters and hot water supply boilers (other than commercial heat pump water heaters).

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§ 431.106 Uniform test method for the measurement of energy efficiency of commercial water heaters and hot water supply boilers (other than commercial heat pump water heaters).

(a) Scope. This section covers the test procedures you must follow if, pursuant to EPCA, you are measuring the thermal efficiency or standby loss, or both, of a storage or instantaneous water heater or hot water supply boiler (other than a commercial heat pump water heater).

(b) Testing and Calculations. Determine the energy efficiency of each covered product by conducting the test procedure(s), set forth in the two rightmost columns of the following table, that apply to the energy efficiency descriptor(s) for that product:

Table 1 to § 431.106 - Test Procedures for Commercial Water Heaters and Hot Water Supply Boilers

[Other than commercial heat pump water heaters]

Equipment type Energy efficiency descriptor Use test setup, equipment and procedures in subsection labeled “Method of Test” of Test procedure required for compliance until With these additional stipulations
Gas-fired Storage and Instantaneous Water Heaters and Hot Water Supply Boilers * Thermal Efficiency
Standby Loss
ANSI Z21.10.3-1998 **, § 2.9
ANSI Z21.10.3-1998 **, § 2.10
May 13, 2013
May 13, 2013
A. For all products, the duration of the standby loss test shall be until whichever of the following occurs first after you begin to measure the fuel and/or electric consumption: (1) The first cutout after 24 hours or (2) 48 hours, if the water heater is not in the heating mode at that time.
B. For oil and gas products, the standby loss in Btu per hour must be calculated as follows: SL (Btu per hour) = S (% per hour) × 8.25 (Btu/gal-F) × Measured Volume (gal) × 70 (degrees F).
C. For oil-fired products, apply the following in conducting the thermal efficiency and standby loss tests: (1) Venting Requirements - Connect a vertical length of flue pipe to the flue gas outlet of sufficient height so as to meet the minimum draft specified by the manufacturer. (2) Oil Supply - Adjust the burner rate so that: (a) The hourly Btu input rate lies within ±2 percent of the manufacturer's specified input rate, (b) the CO2 reading shows the value specified by the manufacturer, (c) smoke in the flue does not exceed No. 1 smoke as measured by the procedure in ASTM-D-2156-80, and (d) fuel pump pressure lies within ±10 percent of manufacturer's specifications.
D. For electric products, apply the following in conducting the standby loss test: (1) Assume that the thermal efficiency (Et) of electric water heaters with immersed heating elements is 98 percent. (2) Maintain the electrical supply voltage to within ±5 percent of the center of the voltage range specified on the water heater nameplate. (3) If the set up includes multiple adjustable thermostats, set the highest one first to yield a maximum water temperature in the specified range as measured by the topmost tank thermocouple. Then set the lower thermostat(s) to yield a maximum mean tank temperature within the specified range.
E. Install water-tube water heaters as shown in Figure 2, “Arrangement for Testing Water-tube Type Instantaneous and Circulating Water Heaters.”

* As to hot water supply boilers with a capacity of less than 10 gallons, these test methods become mandatory on October 21, 2005. Prior to that time, you may use for these products either (1) these test methods if you rate the product for thermal efficiency, or (2) the test methods in Subpart E if you rate the product for combustion efficiency as a commercial packaged boiler.

** Incorporated by reference, see § 431.105.

Table 2 to § 431.106 - Test Procedures for Commercial Water Heaters and Hot Water Supply Boilers

[Other Than Commercial Heat Pump Water Heaters]

Equipment type Energy
efficiency
descriptor
Test procedure Test procedure
required for
compliance on
and after
With these additional stipulations
Residential-Duty Commercial Water Heater Uniform Energy Factor 10 CFR Part 430 , Subpart B, Appendix E December 31, 2015*** None.
Gas-fired Storage and Instantaneous Water Heaters and Hot Water Supply Boilers* Thermal Efficiency Use test set-up, equipment, and procedures in subsection labeled “Method of Test” of ANSI Z21.10.3-2011**, Exhibit G1 May 13, 2013 A. For all products, the duration of the standby loss test shall be until whichever of the following occurs first after you begin to measure the fuel and/or electric consumption: (1) The first cut-out after 24 hours or (2) 48 hours, if the water heater is not in the heating mode at that time.
Standby Loss Use test set-up, equipment, and procedures in subsection labeled “Method of Test” of ANSI Z21.10.3-2011**, Exhibit G2 May 13, 2013 B. For oil and gas products, the standby loss in Btu per hour must be calculated as follows: SL (Btu per hour) = S (% per hour) × 8.25 (Btu/gal-F) × Measured Volume (gal) × 70 (degrees F).
Oil-fired Storage and Instantaneous Water Heaters and Hot Water Supply Boilers* Thermal Efficiency
Standby Loss
ANSI Z21.10.3-2011**, Exhibit G1
Use test set-up, equipment, and procedures in subsection labeled “Method of Test” of ANSI Z21.10.3-2011**, Exhibit G2
May 13, 2013
May 13, 2013
C. For oil-fired products, apply the following in conducting the thermal efficiency and standby loss tests: (1) Venting Requirements - Connect a vertical length of flue pipe to the flue gas outlet of sufficient height so as to meet the minimum draft specified by the manufacturer. (2) Oil Supply - Adjust the burner rate so that: (a) The hourly Btu input rate lies within ±2 percent of the manufacturer's specified input rate, (b) the CO2 reading shows the value specified by the manufacturer, (c) smoke in the flue does not exceed No. 1 smoke as measured by the procedure in ASTM-D2156-80 (reference for guidance only, see § 431.104), and (d) fuel pump pressure lies within ±10 percent of manufacturer's specifications.
Electric Storage and Instantaneous Water Heaters Standby Loss Use test set-up, equipment, and procedures in subsection labeled “Method of Test” of ANSI Z21.10.3-2011**, Exhibit G2 May 13, 2013 D. For electric products, apply the following in conducting the standby loss test: (1) Assume that the thermal efficiency (Et) of electric water heaters with immersed heating elements is 98 percent. (2) Maintain the electrical supply voltage to within ±5 percent of the center of the voltage range specified on the water heater nameplate. (3) If the set up includes multiple adjustable thermostats, set the highest one first to yield a maximum water temperature in the specified range as measured by the topmost tank thermocouple. Then set the lower thermostat(s) to yield a maximum mean tank temperature within the specified range.
E. Install water-tube water heaters as shown in Figure 2, “Arrangement for Testing Water-tube Type Instantaneous and Circulating Water Heaters.”

* As to hot water supply boilers with a capacity of less than 10 gallons, these test methods become mandatory on October 21, 2005. Prior to that time, you may use for these products either (1) these test methods if you rate the product for thermal efficiency, or (2) the test methods in subpart E if you rate the product for combustion efficiency as a commercial packaged boiler.

** Incorporated by reference, see § 431.105.

*** Because the statute permits use of a conversion factor until the later of December 31, 2015 or one year after publication of a conversion factor final rule, DOE may amend the mandatory compliance date for use of this amended test procedure, as necessary.

[77 FR 28996, May 16, 2012, as amended at 79 FR 40586, July 11, 2014]

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