Quiero saber acerca de...

35666

Federal Register / Vol. 86, No. 127 / Wednesday, July 7, 2021 / Proposed Rules
furnaces are likely to exceed 450 F. If so, DOE also seeks comment on the number and types of thermocouples or other temperature measurement devices, that laboratories use to measure the stack temperatures of such gas-fired furnaces.
Issue 25: DOE requests comment on the accuracy of measurement devices currently used to test oil-fired furnaces or gas-fired furnaces with stack temperatures exceeding 450 F.
Issue 26: DOE requests comment on any burdens that would be associated with adding specifications to address the measurement of outlet air temperatures greater than 450 F.

khammond on DSKJM1Z7X2PROD with PROPOSALS

7. Dual-Fuel Heating Products Some residential heating products include an electric heat pump and gas burner, often referred to as dual-fuel or hybrid heating units. These products are designed to provide heating with the heat pump and/or gas burner, depending on the operating conditions e.g., outdoor air temperature and heating demand. The annual operating characteristics of a dual-fuel product may differ significantly from a typical furnace. This is because the inclusion of a heat pump may change the amount of operating time necessary to meet the heating load demand when compared with a gas burner alone, resulting in changes to the operating hours of the fan. Therefore, the estimated national annual operating values provided in Table IV.2 of Appendix AA may not be representative of an average use cycle for furnaces installed in dual-fuel applications. In addition, under the current DOE test procedure, there are no provisions to set up or operate furnace fans as dual-fuel heating units.
Issue 27: DOE requests comment on the typical operating characteristics of dual-fuel systems. Specifically, DOE
requests comment on what conditions dictate when the heat pump or gas burner are providing heat, and during what conditions the heat pump and gas burner operate simultaneously.
Issue 28: DOE requests comment on whether and how the user has control over which heating source is used in a dual-fuel system.
8. Two-Stage Furnaces With LimitedDuration Reduced Stages The DOE test procedure requires testing two-stage furnaces in reduced heating mode, which corresponds to burner operation at the nameplate minimum input rating. Section 8.6.3, Appendix AA. Typically, two-stage furnaces determine whether to operate at the reduced or maximum input based on heating demand and are capable of
VerDate Sep<11>2014

16:33 Jul 06, 2021

Jkt 253001

operating in reduced heating mode for extended periods of time if demand remains low. However, DOE has identified two-stage furnace models that use the reduced heating stage only temporarily and that ramp-up to the high heating stage after a pre-set period of time if the call for heat from the thermostat is not satisfied. DOE has observed that the ramp-up period for these models may be configurable by the user, but is temporary and shorter in duration than the time required to achieve the steady-state conditions during a test.5 A ramp period that is shorter than the DOE-required period to achieve steady-state precludes these furnaces from completing a valid test as a two-stage furnace because the steadystate conditions cannot be met at the reduced input rate before the unit automatically ramps up to the maximum input rate.
Issue 29: DOE requests comment on how the industry currently tests and certifies two-stage furnaces that automatically ramp up from the reduced input to the maximum input after a set period.
Issue 30: DOE requests comment on the prevalence of two-stage furnaces that are controlled such that they are unable to achieve steady-state operation under the DOE test procedure in reduced heating mode.
9. Furnaces Shipped Without Burners DOE is aware that some furnaces are shipped without a burner and the furnace manufacturer specifies one or multiple options for compatible burners in product literature e.g., brochures and installation manuals. This is particularly common for oil-fired furnaces. In cases where multiple burner options from multiple manufacturers are specified, the different burners may have performance differences that impact FER even though the various options may each provide the same heating capacity. These burners may be constructed differently between manufacturers, potentially resulting in different steady-state heating efficiency and/or different airflow resistance characteristics, both of which would impact FER. DOEs furnace fan test procedure and certification requirements do not specify 5 For gas and oil furnaces, Section 8.3 of Appendix AA specifies that steady-state operation is indicated by specific defined ranges of ESP and temperature for 3 measurements taken 15 minutes apart, for a total steady-state operation period of 30
minutes. For electric furnaces and modular blowers, Section 8.4 of Appendix AA specifies that steadystate operation is indicated by specific defined ranges of ESP and temperature for 4 measurements taken 15 minutes apart, for a total steady-state operation period of 45 minutes.

PO 00000

Frm 00007

Fmt 4702

Sfmt 4702

whether to test and certify a furnace that is compatible with multiple burners with each specified burner, or a single manufacturer-specified burner. If different burner options are used in tests for a given oil furnace and burner selection impacts FER, this could result in test repeatability issues.
Issue 31: DOE requests comments on whether and by how much burner selection can impact furnace fan performance, particularly as measured by FER. If burner selection does impact furnace fan performance, DOE requests comment on potential approaches for specifying burners for testing.
10. Test Procedure Repeatability DOE understands that variations in ESP 6 or ambient conditions such as dry bulb temperature or relative humidity can affect test results. In particular, the relative humidity and dry bulb temperature of the test room must be measured at the beginning of the test, but there is no specified value or tolerance that must be met. DOE seeks comment and information on whether these factors could pose a challenge to obtaining repeatable test results and reproducible results across laboratories.
Issue 32: DOE requests comment on whether stakeholders have encountered difficulty obtaining repeatable and reproducible FER results using Appendix AA. Specifically, DOE seeks information and data on how significantly fluctuations in ESP and ambient conditions within the boundaries allowed by Appendix AA
can impact FER ratings.
C. Test Procedure Waivers A person may seek a waiver from the test procedure requirements for a particular basic model of a type of covered product when the basic model for which the petition for waiver is submitted contains one or more design characteristics that: 1 Prevent testing according to the prescribed test procedure, or 2 cause the prescribed test procedures to evaluate the basic model in a manner so unrepresentative of its true energy consumption characteristics as to provide materially inaccurate comparative data. 10 CFR
430.27a1. On February 20, 2019, DOE
received a petition for waiver and an application for interim waiver from ECR
International, Inc. ECR for several 6 Table 1 in Section 8.6.1.2 specifies the required minimum external static pressure in the maximum airflow-control setting by installation type. For each installation type, the furnace fan must be tested within a 0.05 in. w.c. range of the required ESP test condition. ESP adjustment is accomplished by symmetrically restricting the outlet of the test duct until the target ESP condition is attained within tolerance.

E:FRFM07JYP1.SGM

07JYP1