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Electronic Code of Federal Regulations

e-CFR data is current as of February 25, 2020

Title 10Chapter IISubchapter DPart 431 → Subpart R


Title 10: Energy
PART 431—ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT


Subpart R—Walk-in Coolers and Walk-in Freezers


Contents
§431.301   Purpose and scope.
§431.302   Definitions concerning walk-in coolers and walk-in freezers.

Test Procedures

§431.303   Materials incorporated by reference.
§431.304   Uniform test method for the measurement of energy consumption of walk-in coolers and walk-in freezers.
§431.305   Walk-in cooler and walk-in freezer labeling requirements.

Energy Conservation Standards

§431.306   Energy conservation standards and their effective dates.
Appendix A to Subpart R of Part 431—Uniform Test Method for the Measurement of Energy Consumption of the Components of Envelopes of Walk-In Coolers and Walk-In Freezers
Appendix B to Subpart R of Part 431—Uniform Test Method for the Measurement of R-Value for Envelope Components of Walk-In Coolers and Walk-In Freezers
Appendix C to Subpart R of Part 431—Uniform Test Method for the Measurement of Net Capacity and AWEF of Walk-In Cooler and Walk-In Freezer Refrigeration Systems

Source: 74 FR 12074, Mar. 23, 2009, unless otherwise noted.

§431.301   Purpose and scope.

This subpart contains energy conservation requirements for walk-in coolers and walk-in freezers, pursuant to Part C of Title III of the Energy Policy and Conservation Act, as amended, 42 U.S.C. 6311-6317.

§431.302   Definitions concerning walk-in coolers and walk-in freezers.

Adaptive defrost means a factory-installed defrost control system that reduces defrost frequency by initiating defrosts or adjusting the number of defrosts per day in response to operating conditions (e.g., moisture levels in the refrigerated space, measurements that represent coil frost load) rather than initiating defrost strictly based on compressor run time or clock time.

Basic model means all components of a given type of walk-in cooler or walk-in freezer (or class thereof) manufactured by one manufacturer, having the same primary energy source, and which have essentially identical electrical, physical, and functional (or hydraulic) characteristics that affect energy consumption, energy efficiency, water consumption, or water efficiency; and

(1) With respect to panels, which do not have any differing features or characteristics that affect U-factor.

(2) [Reserved]

Dedicated condensing unit means a positive displacement condensing unit that is part of a refrigeration system (as defined in this section) and is an assembly that

(1) Includes 1 or more compressors, a condenser, and one refrigeration circuit; and

(2) Is designed to serve one refrigerated load.

Dedicated condensing refrigeration system means one of the following:

(1) A dedicated condensing unit;

(2) A single-package dedicated system; or

(3) A matched refrigeration system.

Display door means a door that:

(1) Is designed for product display; or

(2) Has 75 percent or more of its surface area composed of glass or another transparent material.

Display panel means a panel that is entirely or partially comprised of glass, a transparent material, or both and is used for display purposes.

Door means an assembly installed in an opening on an interior or exterior wall that is used to allow access or close off the opening and that is movable in a sliding, pivoting, hinged, or revolving manner of movement. For walk-in coolers and walk-in freezers, a door includes the door panel, glass, framing materials, door plug, mullion, and any other elements that form the door or part of its connection to the wall.

Envelope means—

(1) The portion of a walk-in cooler or walk-in freezer that isolates the interior, refrigerated environment from the ambient, external environment; and

(2) All energy-consuming components of the walk-in cooler or walk-in freezer that are not part of its refrigeration system.

Freight door means a door that is not a display door and is equal to or larger than 4 feet wide and 8 feet tall.

Indoor dedicated condensing refrigeration system means a dedicated condensing refrigeration system designated by the manufacturer for indoor use or for which there is no designation regarding the use location.

K-factor means the thermal conductivity of a material.

Manufacturer of a walk-in cooler or walk-in freezer means any person who:

(1) Manufactures a component of a walk-in cooler or walk-in freezer that affects energy consumption, including, but not limited to, refrigeration, doors, lights, windows, or walls; or

(2) Manufactures or assembles the complete walk-in cooler or walk-in freezer.

Matched condensing unit means a dedicated condensing unit that is distributed in commerce with one or more unit cooler(s) specified by the condensing unit manufacturer.

Matched refrigeration system (also called “matched-pair”) means a refrigeration system including the matched condensing unit and the one or more unit coolers with which it is distributed in commerce.

Outdoor dedicated condensing refrigeration system means a dedicated condensing refrigeration system designated by the manufacturer for outdoor use.

Panel means a construction component that is not a door and is used to construct the envelope of the walk-in, i.e., elements that separate the interior refrigerated environment of the walk-in from the exterior.

Passage door means a door that is not a freight or display door.

Refrigerated means held at a temperature at or below 55 degrees Fahrenheit using a refrigeration system.

Refrigerated storage space means a space held at refrigerated (as defined in this section) temperatures.

Refrigeration system means the mechanism (including all controls and other components integral to the system's operation) used to create the refrigerated environment in the interior of a walk-in cooler or walk-in freezer, consisting of:

(1) A dedicated condensing refrigeration system (as defined in this section); or

(2) A unit cooler.

Single-packaged dedicated system means a refrigeration system (as defined in this section) that is a single-package assembly that includes one or more compressors, a condenser, a means for forced circulation of refrigerated air, and elements by which heat is transferred from air to refrigerant, without any element external to the system imposing resistance to flow of the refrigerated air.

U-factor means the heat transmission in a unit time through a unit area of a specimen or product and its boundary air films, induced by a unit temperature difference between the environments on each side.

Unit cooler means an assembly, including means for forced air circulation and elements by which heat is transferred from air to refrigerant, thus cooling the air, without any element external to the cooler imposing air resistance.

Walk-in cooler and walk-in freezer mean an enclosed storage space refrigerated to temperatures, respectively, above, and at or below 32 degrees Fahrenheit that can be walked into, and has a total chilled storage area of less than 3,000 square feet; however the terms do not include products designed and marketed exclusively for medical, scientific, or research purposes.

Walk-in process cooling refrigeration system means a refrigeration system that is capable of rapidly cooling food or other substances from one temperature to another. The basic model of such a system must satisfy one of the following three conditions:

(1) Be distributed in commerce with an insulated enclosure consisting of panels and door(s) such that the assembled product has a refrigerating capacity of at least 100 Btu/h per cubic foot of enclosed internal volume;

(2) Be a unit cooler having an evaporator coil that is at least four-and-one-half (4.5) feet in height and whose height is at least one-and-one-half (1.5) times the width. The height of the evaporator coil is measured perpendicular to the tubes and is also the fin height, while its width is the finned length parallel to the tubes, as illustrated in Figure 1; or

(3) Be a dedicated condensing unit that is distributed in commerce exclusively with a unit cooler meeting description (2) or with an evaporator that is not a unit cooler, i.e., an evaporator that is not distributed or installed as part of a package including one or more fans.

eCFR graphic er28de16.006.gif

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[74 FR 12074, Mar. 23, 2009, as amended at 76 FR 12504, Mar. 7, 2011; 76 FR 21604, Apr. 15, 2011; 76 FR 33631, June 9, 2011; 79 FR 32123, June 3, 2014; 81 FR 95801, Dec. 28, 2016]

Test Procedures

§431.303   Materials incorporated by reference.

(a) General. Certain material is incorporated by reference into this part with the approval of the Director of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. Any amendment to a standard by the standard-setting organization will not affect the DOE regulations unless and until amended by DOE. Material is incorporated as it exists on the date of the approval. To enforce any edition other than that specified in this section, the U.S. Department of Energy must publish a document in the Federal Register and the material must be available to the public. All approved material is available for inspection at U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Building Technologies Program, 6th Floor, 950 L'Enfant Plaza SW., Washington, DC 20024, 202-586-2945, between 9 a.m. and 4 p.m., Monday through Friday, except Federal holidays, or go to: http://www1.eere.energy.gov/buildings/appliance__standards/ ], and is available from the sources listed below. It is also available for inspection at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030 or go to http://www.archives.gov/federal__register/code__of__federal__regulations/ibr__locations.html.

(b) AHRI. Air-Conditioning, Heating, and Refrigeration Institute, 2111 Wilson Boulevard, Suite 500, Arlington, VA 22201, (703) 600-0366, or http://www.ahrinet.org.

(1) ANSI/AHRI Standard 420-2008 (“AHRI 420-2008”), “Performance Rating of Forced-Circulation Free-Delivery Unit Coolers for Refrigeration,” Copyright 2008, IBR approved for appendix C to subpart R of part 431.

(2) AHRI Standard 1250P (I-P)-2009 (“AHRI 1250-2009”), “Standard for Performance Rating of Walk-in Coolers and Freezers, (including Errata sheet dated December 2015), copyright 2009, except Table 15 and Table 16. IBR approved for appendix C to subpart R of part 431.

(c) ASHRAE. The American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc., 1971 Tullie Circle NE., Atlanta, GA 30329, or www.ashrae.org/.

(1) ANSI/ASHRAE Standard 23.1-2010, (“ASHRAE 23.1-2010”), “Methods of Testing for Rating the Performance of Positive Displacement Refrigerant Compressors and Condensing Units that Operate at Subcritical Temperatures of the Refrigerant,” ANSI approved January 28, 2010, IBR approved for appendix C to subpart R of part 431.

(2) [Reserved]

(d) ASTM. American Society for Testing and Materials, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, (610) 832-9500, or http://www.astm.org.

(1) IBR approved for appendix B to subpart R of part 431.

(2) [Reserved]

(e) NFRC. National Fenestration Rating Council, 6305 Ivy Lane, Ste. 140, Greenbelt, MD 20770, (301) 589-1776, or http://www.nfrc.org/.

(1) NFRC 100-2010[E0A1], (“NFRC 100”), Procedure for Determining Fenestration Product U-factors, approved June 2010, IBR approved for appendix A to subpart R of part 431.

(2) [Reserved]

[74 FR 12074, Mar. 23, 2009, as amended at 76 FR 21605, Apr. 15, 2011; 76 FR 33631, June 9, 2011; 79 FR 27412, May 13, 2014; 81 FR 95802, Dec. 28, 2016]

§431.304   Uniform test method for the measurement of energy consumption of walk-in coolers and walk-in freezers.

(a) Scope. This section provides test procedures for measuring, pursuant to EPCA, the energy consumption of walk-in coolers and walk-in freezers.

(b) Determine the energy efficiency and/or energy consumption of the specified walk-in cooler and walk-in freezer components by conducting the appropriate test procedure as follows:

(1) Determine the U-factor, conduction load, and energy use of walk-in cooler and walk-in freezer display panels by conducting the test procedure set forth in appendix A to this subpart.

(2) Determine the energy use of walk-in cooler and walk-in freezer display doors and non-display doors by conducting the test procedure set forth in appendix A to this subpart.

(3) Determine the R-value of walk-in cooler and walk-in freezer non-display panels and non-display doors by conducting the test procedure set forth in appendix B to this subpart.

(4) Determine the AWEF and net capacity of walk-in cooler and walk-in freezer refrigeration systems by conducting the test procedure set forth in appendix C to this subpart.

[74 FR 12074, Mar. 23, 2009, as amended at 76 FR 21605, Apr. 15, 2011; 76 FR 33631, June 9, 2011; 76 FR 65365, Oct. 21, 2011; 79 FR 27412, May 13, 2014; 79 FR 32123, June 3, 2014; 81 FR 95802, Dec. 28, 2016]

§431.305   Walk-in cooler and walk-in freezer labeling requirements.

(a) Panel nameplate—(1) Required information. The permanent nameplate of a walk-in cooler or walk-in freezer panel for which standards are prescribed in §431.306 must be marked clearly with the following information:

(i) The panel brand or manufacturer; and

(ii) One of the following statements, as appropriate:

(A) “This panel is designed and certified for use in walk-in cooler applications.”

(B) “This panel is designed and certified for use in walk-in freezer applications.”

(C) “This panel is designed and certified for use in walk-in cooler and walk-in freezer applications.”

(2) Display of required information. All orientation, spacing, type sizes, typefaces, and line widths to display this required information must be the same as or similar to the display of the other performance data included on the panel's permanent nameplate. The permanent nameplate must be visible unless the panel is assembled into a completed walk-in.

(b) Door nameplate—(1) Required information. The permanent nameplate of a walk-in cooler or walk-in freezer door for which standards are prescribed in §431.306 must be marked clearly with the following information:

(i) The door brand or manufacturer; and

(ii) One of the following statements, as appropriate:

(A) “This door is designed and certified for use in walk-in cooler applications.”

(B) “This door is designed and certified for use in walk-in freezer applications.”

(C) “This door is designed and certified for use in walk-in cooler and walk-in freezer applications.”

(2) Display of required information. All orientation, spacing, type sizes, typefaces, and line widths to display this required information must be the same as or similar to the display of the other performance data included on the door's permanent nameplate. The permanent nameplate must be visible unless the door is assembled into a completed walk-in.

(c) Refrigeration system nameplate—(1) Required information. The permanent nameplate of a walk-in cooler or walk-in freezer refrigeration system for which standards are prescribed in §431.306 must be marked clearly with the following information:

(i) The refrigeration system brand or manufacturer;

(ii) The refrigeration system model number;

(iii) The date of manufacture of the refrigeration system (if the date of manufacture is embedded in the unit's serial number, then the manufacturer of the refrigeration system must retain any relevant records to discern the date from the serial number);

(iv) If the refrigeration system is a dedicated condensing refrigeration system, and is not designated for outdoor use, the statement, “Indoor use only” (for a matched pair this must appear on the condensing unit); and

(v) One of the following statements, as appropriate:

(A) “This refrigeration system is designed and certified for use in walk-in cooler applications.”

(B) “This refrigeration system is designed and certified for use in walk-in freezer applications.”

(C) “This refrigeration system is designed and certified for use in walk-in cooler and walk-in freezer applications.”

(2) Process cooling refrigeration systems. The permanent nameplate of a process cooling refrigeration system (as defined in §431.302) must be marked clearly with the statement, “This refrigeration system is designed for use exclusively in walk-in cooler and walk-in freezer process cooling refrigeration applications.”

(3) Display of required information. All orientation, spacing, type sizes, typefaces, and line widths to display this required information must be the same as or similar to the display of the other performance data included on the refrigeration system's permanent nameplate. The model number must be in one of the following forms: “Model ___” or “Model number ___” or “Model No. ___.” The permanent nameplate must be visible unless the refrigeration system is assembled into a completed walk-in.

(d) A manufacturer may not mark the nameplate of a component with the required information if the manufacturer has not submitted a certification of compliance for the relevant model.

(e) Disclosure of efficiency information in marketing materials. Each catalog that lists the component and all materials used to market the component must include:

(1) For panels—The R-value in the form “R-value__.”

(2) For doors—The energy consumption in the form “EC__kWh/day.”

(3) For those refrigeration system for which standards are prescribed—The AWEF in the form “AWEF __.”

(4) The information that must appear on a walk-in cooler or walk-in freezer component's permanent nameplate pursuant to paragraphs (a)-(c) of this section must also be prominently displayed in each catalog that lists the component and all materials used to market the component.

[81 FR 95802, Dec. 28, 2016]

Energy Conservation Standards

§431.306   Energy conservation standards and their effective dates.

(a) Each walk-in cooler or walk-in freezer manufactured on or after January 1, 2009, shall—

(1) Have automatic door closers that firmly close all walk-in doors that have been closed to within 1 inch of full closure, except that this paragraph shall not apply to doors wider than 3 feet 9 inches or taller than 7 feet;

(2) Have strip doors, spring hinged doors, or other method of minimizing infiltration when doors are open;

(3) Contain wall, ceiling, and door insulation of at least R-25 for coolers and R-32 for freezers, except that this paragraph shall not apply to:

(i) Glazed portions of doors not to structural members and

(ii) A walk-in cooler or walk-in freezer component if the component manufacturer has demonstrated to the satisfaction of the Secretary in a manner consistent with applicable requirements that the component reduces energy consumption at least as much as if such insulation requirements of subparagraph (a)(3) were to apply.

(4) Contain floor insulation of at least R-28 for freezers;

(5) For evaporator fan motors of under 1 horsepower and less than 460 volts, use—

(i) Electronically commutated motors (brushless direct current motors); or

(ii) 3-phase motors;

(6) For condenser fan motors of under 1 horsepower, use—

(i) Electronically commutated motors (brushless direct current motors);

(ii) Permanent split capacitor-type motors; or

(iii) 3-phase motors; and

(7) For all interior lights, use light sources with an efficacy of 40 lumens per watt or more, including ballast losses (if any), except that light sources with an efficacy of 40 lumens per watt or less, including ballast losses (if any), may be used in conjunction with a timer or device that turns off the lights within 15 minutes of when the walk-in cooler or walk-in freezer is not occupied by people.

(b) Each walk-in cooler or walk-in freezer with transparent reach-in doors manufactured on or after January 1, 2009, shall also meet the following specifications:

(1) Transparent reach-in doors for walk-in freezers and windows in walk-in freezer doors shall be of triple-pane glass with either heat-reflective treated glass or gas fill.

(2) Transparent reach-in doors for walk-in coolers and windows in walk-in cooler doors shall be—

(i) Double-pane glass with heat-reflective treated glass and gas fill; or

(ii) Triple-pane glass with either heat-reflective treated glass or gas fill.

(3) If the walk-in cooler or walk-in freezer has an antisweat heater without antisweat heat controls, the walk-in cooler and walk-in freezer shall have a total door rail, glass, and frame heater power draw of not more than 7.1 watts per square foot of door opening (for freezers) and 3.0 watts per square foot of door opening (for coolers).

(4) If the walk-in cooler or walk-in freezer has an antisweat heater with antisweat heat controls, and the total door rail, glass, and frame heater power draw is more than 7.1 watts per square foot of door opening (for freezers) and 3.0 watts per square foot of door opening (for coolers), the antisweat heat controls shall reduce the energy use of the antisweat heater in a quantity corresponding to the relative humidity in the air outside the door or to the condensation on the inner glass pane.

(c) Walk-in cooler and freezer display doors. All walk-in cooler and walk-in freezer display doors manufactured starting June 5, 2017, must satisfy the following standards:

Class descriptorClassEquations for
maximum energy
consumption
(kWh/day)*
Display Door, Medium TemperatureDD.M0.04 × Add + 0.41.
Display Door, Low TemperatureDD.L0.15 × Add + 0.29.

*Add represents the surface area of the display door.

(d) Walk-in cooler and freezer non-display doors. All walk-in cooler and walk-in freezer non-display doors manufactured starting on June 5, 2017, must satisfy the following standards:

Class descriptorClassEquations for
maximum energy
consumption
(kWh/day)*
Passage door, Medium TemperaturePD.M0.05 × And + 1.7.
Passage Door, Low TemperaturePD.L0.14 × And + 4.8.
Freight Door, Medium TemperatureFD.M0.04 × And + 1.9.
Freight Door, Low TemperatureFD.L0.12 × And + 5.6.

*And represents the surface area of the non-display door.

(e) Walk-in cooler refrigeration systems. All walk-in cooler and walk-in freezer refrigeration systems manufactured starting on the dates listed in the table, except for walk-in process cooling refrigeration systems (as defined in §431.302), must satisfy the following standards:

Equipment classMinimum AWEF
(Btu/W-h)*
Compliance date: equipment manufactured starting on .  .  .
Dedicated Condensing System—Medium, Indoor5.61June 5, 2017.
Dedicated Condensing System—Medium, Outdoor7.60
Dedicated Condensing System—Low, Indoor with a Net Capacity (qnet) of:
< 6,500 Btu/h9.091 × 10−5 × qnet + 1.81July 10, 2020.
≥ 6,500 Btu/h2.40
Dedicated Condensing System—Low, Outdoor with a Net Capacity (qnet) of:
< 6,500 Btu/h6.522 × 10−5 × qnet + 2.73
≥ 6,500 Btu/h3.15
Unit Cooler—Medium9.00
Unit Cooler—Low with a Net Capacity (qnet) of:
< 15,500 Btu/h1.575 × 10−5 × qnet + 3.91
≥ 15,500 Btu/h4.15

*Where qnet is net capacity as determined in accordance with §431.304 and certified in accordance with 10 CFR part 429.

[74 FR 12074, Mar. 23, 2009, as amended at 78 FR 62993, Oct. 23, 2013; 79 FR 32123, June 3, 2014; 80 FR 69838, Nov. 12, 2015; 82 FR 31885, July 10, 2017]

Appendix A to Subpart R of Part 431—Uniform Test Method for the Measurement of Energy Consumption of the Components of Envelopes of Walk-In Coolers and Walk-In Freezers

1.0 Scope

This appendix covers the test requirements used to measure the energy consumption of the components that make up the envelope of a walk-in cooler or walk-in freezer.

2.0 Definitions

The definitions contained in §431.302 are applicable to this appendix.

3.0 Additional Definitions

3.1 Automatic door opener/closer means a device or control system that “automatically” opens and closes doors without direct user contact, such as a motion sensor that senses when a forklift is approaching the entrance to a door and opens it, and then closes the door after the forklift has passed.

3.2-3.3 [Reserved]

3.4   Surface area means the area of the surface of the walk-in component that would be external to the walk-in cooler or walk-in freezer as appropriate.

3.5   Rated power means the electricity consuming device's power as specified on the device's nameplate. If the device does not have a nameplate or such nameplate does not list the device's power, then the rated power must be read from the device's product data sheet.

3.6   Rating conditions means, unless explicitly stated otherwise, all conditions shown in Table A.1 of this section.

3.7 Percent time off (PTO) means the percent of time that an electrical device is assumed to be off.

Table A.1—Temperature Conditions

      
Internal Temperatures (cooled space within the envelope)
Cooler Dry Bulb Temperature35 °F
Freezer Dry Bulb Temperature−10 °F
External Temperatures (space external to the envelope)
Freezer and Cooler Dry Bulb Temperatures75 °F.

4.0 Calculation Instructions

4.1 Display Panels

(a) Calculate the U-factor of the display panel in accordance with section 5.3 of this appendix, Btu/h-ft2- °F.

(b) Calculate the display panel surface area, as defined in section 3.4 of this appendix, Adp, ft2, with standard geometric formulas or engineering software.

(c) Calculate the temperature differential, ΔTdp, °F, for the display panel, as follows:

eCFR graphic er09jn11.003.gif

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Where:

TDB,ext,dp = dry-bulb air external temperature, °F, as prescribed in Table A.1; and

TDB,int,dp = dry-bulb air temperature internal to the cooler or freezer, °F, as prescribed in Table A.1.

(d) Calculate the conduction load through the display panel, Qcond-dp, Btu/h, as follows:

eCFR graphic er09jn11.004.gif

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Where:

Adp = surface area of the walk-in display panel, ft2;

ΔTdp = temperature differential between refrigerated and adjacent zones, °F; and

Udp = thermal transmittance, U-factor, of the display panel in accordance with section 5.3 of this appendix, Btu/h-ft2- °F.

(e) Select Energy Efficiency Ratio (EER), as follows:

(1) For coolers, use EER = 12.4 Btu/W-h

(2) For freezers, use EER = 6.3 Btu/W-h

(f) Calculate the total daily energy consumption, Edp, kWh/day, as follows:

eCFR graphic er09jn11.005.gif

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Where:

Qcond, dp = the conduction load through the display panel, Btu/h; and EER = EER of walk-in (cooler or freezer), Btu/W-h.

4.2 [Reserved]

4.3 [Reserved]

4.4   Display Doors

4.4.1   Conduction Through Display Doors

(a) Calculate the U-factor of the door in accordance with section 5.3 of this appendix, Btu/h-ft2- °F

(b) Calculate the surface area, as defined in section 3.4 of this appendix, of the display door, Add, ft2, with standard geometric formulas or engineering software.

(c) Calculate the temperature differential, ΔTdd, °F, for the display door as follows:

eCFR graphic er09jn11.020.gif

View or download PDF

Where:

TDB,ext, dd = dry-bulb air temperature external to the display door, °F, as prescribed in Table A.1; and

TDB,int, dd = dry-bulb air temperature internal to the display door, °F, as prescribed in Table A.1.

(d) Calculate the conduction load through the display doors, Qcond-dd, Btu/h, as follows:

eCFR graphic er09jn11.021.gif

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Where:

ΔTdd = temperature differential between refrigerated and adjacent zones, °F;

Add = surface area walk-in display doors, ft2; and

Udd = thermal transmittance, U-factor of the door, in accordance with section 5.3 of this appendix, Btu/h-ft2- °F.

4.4.2   Direct Energy Consumption of Electrical Component(s) of Display Doors

Electrical components associated with display doors could include, but are not limited to: heater wire (for anti-sweat or anti-freeze application); lights (including display door lighting systems); control system units; and sensors.

(a) Select the required value for percent time off (PTO) for each type of electricity consuming device, PTOt (%)

(1) For lights without timers, control system or other demand-based control, PTO = 25 percent. For lighting with timers, control system or other demand-based control, PTO = 50 percent.

(2) For anti-sweat heaters on coolers (if included): Without timers, control system or other demand-based control, PTO = 0 percent. With timers, control system or other demand-based control, PTO = 75 percent. For anti-sweat heaters on freezers (if included): Without timers, control system or other auto-shut-off systems, PTO = 0 percent. With timers, control system or other demand-based control, PTO = 50 percent.

(3) For all other electricity consuming devices: Without timers, control system, or other auto-shut-off systems, PTO = 0 percent. If it can be demonstrated that the device is controlled by a preinstalled timer, control system or other auto-shut-off system, PTO = 25 percent.

(b) Calculate the power usage for each type of electricity consuming device, Pdd-comp,u,t, kWh/day, as follows:

eCFR graphic er09jn11.022.gif

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Where:

u = the index for each of type of electricity-consuming device located on either (1) the interior facing side of the display door or within the inside portion of the display door, (2) the exterior facing side of the display door, or (3) any combination of (1) and (2). For purposes of this calculation, the interior index is represented by u = int and the exterior index is represented by u = ext. If the electrical component is both on the interior and exterior side of the display door then u = int. For anti-sweat heaters sited anywhere in the display door, 75 percent of the total power is be attributed to u = int and 25 percent of the total power is attributed to u = ext;

t = index for each type of electricity consuming device with identical rated power;

Prated,u,t = rated power of each component, of type t, kW;

PTOu,t = percent time off, for device of type t, %; and

nu,t = number of devices at the rated power of type t, unitless.

(c) Calculate the total electrical energy consumption for interior and exterior power, Pdd-tot, int (kWh/day) and Pdd-tot, ext (kWh/day), respectively, as follows:

eCFR graphic er09jn11.023.gif

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Where:

t = index for each type of electricity consuming device with identical rated power;

Pdd-comp,int, t = the energy usage for an electricity consuming device sited on the interior facing side of or in the display door, of type t, kWh/day; and

Pdd-comp,ext, t = the energy usage for an electricity consuming device sited on the external facing side of the display door, of type t, kWh/day.

(d) Calculate the total electrical energy consumption, Pdd-tot, (kWh/day), as follows:

eCFR graphic er09jn11.024.gif

View or download PDF

Where:

Pdd-tot,int = the total interior electrical energy usage for the display door, kWh/day; and

Pdd-tot,ext = the total exterior electrical energy usage for the display door, kWh/day.

4.4.3   Total Indirect Electricity Consumption Due to Electrical Devices

(a) Select Energy Efficiency Ratio (EER), as follows:

(1) For coolers, use EER = 12.4 Btu/Wh

(2) For freezers, use EER = 6.3 Btu/Wh

(b) Calculate the additional refrigeration energy consumption due to thermal output from electrical components sited inside the display door, Cdd-load, kWh/day, as follows:

eCFR graphic er09jn11.025.gif

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Where:

EER = EER of walk-in cooler or walk-in freezer, Btu/W-h; and

Pdd-tot,int = The total internal electrical energy consumption due for the display door, kWh/day.

4.4.4   Total Display Door Energy Consumption

(a) Select Energy Efficiency Ratio (EER), as follows:

(1) For coolers, use EER = 12.4 Btu/W-h

(2) For freezers, use EER = 6.3 Btu/W-h

(b) Calculate the total daily energy consumption due to conduction thermal load, Edd, thermal, kWh/day, as follows:

eCFR graphic er09jn11.026.gif

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Where:

Qcond, dd = the conduction load through the display door, Btu/h; and

EER = EER of walk-in (cooler or freezer), Btu/W-h.

(c) Calculate the total energy, Edd,tot, kWh/day,

eCFR graphic er09jn11.027.gif

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Where:

Edd, thermal = the total daily energy consumption due to thermal load for the display door, kWh/day;

Pdd-tot = the total electrical load, kWh/day; and

Cdd-load = additional refrigeration load due to thermal output from electrical components contained within the display door, kWh/day.

4.5   Non-Display Doors

4.5.1   Conduction Through Non-Display Doors

(a) Calculate the surface area, as defined in section 3.4 of this appendix, of the non-display door, And, ft2, with standard geometric formulas or with engineering software.

(b) Calculate the temperature differential of the non-display door, ΔTnd, °F, as follows:

eCFR graphic er09jn11.028.gif

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Where:

TDB,ext, nd = dry-bulb air external temperature, °F, as prescribed by Table A.1; and

TDB,int, nd = dry-bulb air internal temperature, °F, as prescribed by Table A.1. If the component spans both cooler and freezer spaces, the freezer temperature must be used.

(c) Calculate the conduction load through the non-display door: Qcond-nd, Btu/h,

eCFR graphic er09jn11.029.gif

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Where:

ΔTnd = temperature differential across the non-display door, °F;

Und = thermal transmittance, U-factor of the door, in accordance with section 5.3 of this appendix, Btu/h-ft2- °F; and

And = area of non-display door, ft2.

4.5.2   Direct Energy Consumption of Electrical Components of Non-Display Doors

Electrical components associated with a walk-in non-display door comprise any components that are on the non-display door and that directly consume electrical energy. This includes, but is not limited to, heater wire (for anti-sweat or anti-freeze application), control system units, and sensors.

(a) Select the required value for percent time off for each type of electricity consuming device, PTOt (%)

(1) For lighting without timers, control system or other demand-based control, PTO = 25 percent. For lighting with timers, control system or other demand-based control, PTO = 50 percent.

(2) For anti-sweat heaters on coolers (if included): Without timers, control system or other demand-based control, PTO = 0 percent. With timers, control system or other demand-based control, PTO = 75 percent. For anti-sweat heaters on freezers (if included): Without timers, control system or other auto-shut-off systems, PTO = 0 percent. With timers, control system or other demand-based control, PTO = 50 percent.

(3) For all other electricity consuming devices: Without timers, control system, or other auto-shut-off systems, PTO = 0 percent. If it can be demonstrated that the device is controlled by a preinstalled timer, control system or other auto-shut-off system, PTO = 25 percent.

(b) Calculate the power usage for each type of electricity consuming device, Pnd-comp,u,t, kWh/day, as follows:

eCFR graphic er09jn11.030.gif

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Where:

u = the index for each of type of electricity-consuming device located on either (1) the interior facing side of the display door or within the inside portion of the display door, (2) the exterior facing side of the display door, or (3) any combination of (1) and (2). For purposes of this calculation, the interior index is represented by u = int and the exterior index is represented by u = ext. If the electrical component is both on the interior and exterior side of the display door then u = int. For anti-sweat heaters sited anywhere in the display door, 75 percent of the total power is be attributed to u = int and 25 percent of the total power is attributed to u = ext;

t = index for each type of electricity consuming device with identical rated power;

Prated,u,t = rated power of each component, of type t, kW;

PTOu,t = percent time off, for device of type t, %; and

nu,t = number of devices at the rated power of type t, unitless.

(c) Calculate the total electrical energy consumption for interior and exterior power, Pnd-tot, int (kWh/day) and Pnd-tot, ext (kWh/day), respectively, as follows:

eCFR graphic er09jn11.031.gif

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Where:

t = index for each type of electricity consuming device with identical rated power;

Pnd-comp,int, t = the energy usage for an electricity consuming device sited on the internal facing side or internal to the non-display door, of type t, kWh/day; and

Pnd-comp,ext, t = the energy usage for an electricity consuming device sited on the external facing side of the non-display door, of type t, kWh/day. For anti-sweat heaters,

(d) Calculate the total electrical energy consumption, Pnd-tot, kWh/day, as follows:

eCFR graphic er09jn11.032.gif

View or download PDF

Where:

Pnd-tot,int = the total interior electrical energy usage for the non-display door, of type t, kWh/day; and

Pnd-tot,ext = the total exterior electrical energy usage for the non-display door, of type t, kWh/day.

4.5.3   Total Indirect Electricity Consumption Due to Electrical Devices

(a) Select Energy Efficiency Ratio (EER), as follows:

(1) For coolers, use EER = 12.4 Btu/Wh

(2) For freezers, use EER = 6.3 Btu/Wh

(b) Calculate the additional refrigeration energy consumption due to thermal output from electrical components associated with the non-display door, Cnd-load, kWh/day, as follows:

eCFR graphic er09jn11.033.gif

View or download PDF

Where:

EER = EER of walk-in cooler or freezer, Btu/W-h; and

Pnd-tot,int = the total interior electrical energy consumption for the non-display door, kWh/day.

4.5.4   Total Non-Display Door Energy Consumption

(a) Select Energy Efficiency Ratio (EER), as follows:

(1) For coolers, use EER = 12.4 Btu/W-h

(2) For freezers, use EER = 6.3 Btu/W-h

(b) Calculate the total daily energy consumption due to thermal load, End, thermal, kWh/day, as follows:

eCFR graphic er09jn11.034.gif

View or download PDF

Where:

Qcond-nd = the conduction load through the non-display door, Btu/hr; and

EER = EER of walk-in (cooler or freezer), Btu/W-h.

(c) Calculate the total energy, End,tot, kWh/day, as follows:

eCFR graphic er09jn11.035.gif

View or download PDF

Where:

End, thermal = the total daily energy consumption due to thermal load for the non-display door, kWh/day;

Pnd-tot = the total electrical energy consumption, kWh/day; and

Cnd-load = additional refrigeration load due to thermal output from electrical components contained on the inside face of the non-display door, kWh/day.

5.0   Test Methods and Measurements

5.1-5.2 [Reserved]

5.3   U-factor of Doors and Display Panels

(a) Follow the procedure in NFRC 100, (incorporated by reference; see §431.303), exactly, with these exceptions:

(1) The average surface heat transfer coefficient on the cold-side of the apparatus shall be 30 Watts per square-meter-Kelvin (W/m2*K) ±5%. The average surface heat transfer coefficient on the warm-side of the apparatus shall be 7.7 Watts per square-meter-Kelvin (W/m2*K) ±5%.

(2) Cold-side conditions:

(i) Air temperature of 35 °F (1.7 °C) for cooler doors and −10 °F (−23.3 °C) for freezer doors

(ii) Mean inside radiant temperature must be the same as shown in section 5.3(a)(2)(i), above.

(3) Warm-side conditions

(i) Air temperature of 75 °F (23.9 °C)

(ii) Mean outside radiant temperature must be the same as section 5.3(a)(3)(i), above.

(4) Direct solar irradiance = 0 W/m2 (Btu/h-ft2).

(b) Required Test Measurements

(i) Display Doors and Display Panels

1. Thermal Transmittance: Udd

(ii) Non-Display Door

1. Thermal Transmittance: Und

[76 FR 21606, Apr. 15, 2011, as amended at 76 FR 31796, June 2, 2011; 76 FR 33632, June 9, 2011; 79 FR 27414, May 13, 2014; 81 FR 95803, Dec. 28, 2016]

Appendix B to Subpart R of Part 431—Uniform Test Method for the Measurement of R-Value for Envelope Components of Walk-In Coolers and Walk-In Freezers

1.0   Scope

This appendix covers the test requirements used to measure the R-value of non-display panels and non-display doors of a walk-in cooler or walk-in freezer.

2.0   Definitions

The definitions contained in §431.302 apply to this appendix.

3.0   Additional Definitions

3.1   Edge region means a region of the panel that is wide enough to encompass any framing members. If the panel contains framing members (e.g., a wood frame) then the width of the edge region must be as wide as any framing member plus an additional 2 in. ± 0.25 in.

4.0   Test Methods, Measurements, and Calculations

4.1   The R value shall be the 1/K factor multiplied by the thickness of the panel.

4.2   The K factor shall be based on ASTM C518 (incorporated by reference; see §431.303).

4.3   For calculating the R value for freezers, the K factor of the foam at 20 ± 1 degrees Fahrenheit (average foam temperature) shall be used. Test results from a test sample 1 ±0.1-inches in thickness may be used to determine the R value of panels with various foam thickness as long as the foam is of the same final chemical form.

4.4   For calculating the R value for coolers, the K factor of the foam at 55 ± 1 degrees Fahrenheit (average foam temperature) shall be used. Test results from a test sample 1 ± 0.1-inches in thickness may be used to determine the R value of panels with various foam thickness as long as the foam is of the same final chemical form.

4.5   Foam shall be tested after it is produced in its final chemical form. For foam produced inside of a panel (“foam-in-place”), “final chemical form” means the foam is cured as intended and ready for use as a finished panel. For foam produced as board stock (typically polystyrene), “final chemical form” means after extrusion and ready for assembly into a panel or after assembly into a panel. Foam from foam-in-place panels must not include any structural members or non-foam materials. Foam produced as board stock may be tested prior to its incorporation into a final panel. A test sample 1 ± 0.1-inches in thickness must be taken from the center of a panel and any protective skins or facers must be removed. A high-speed band-saw and a meat slicer are two types of recommended cutting tools. Hot wire cutters or other heated tools must not be used for cutting foam test samples. The two surfaces of the test sample that will contact the hot plate assemblies (as defined in ASTM C518 (incorporated by reference, see §431.303)) must both maintain ±0.03 inches flatness tolerance and also maintain parallelism with respect to one another within ±0.03 inches. Testing must be completed within 24 hours of samples being cut for testing.

4.6   Internal non-foam member and/or edge regions shall not be considered when testing in accordance with ASTM C518 (incorporated by reference, see §431.303).

4.7   For panels consisting of two or more layers of dissimilar insulating materials (excluding facers or protective skins), test each material as described in sections 4.1 through 4.6 of this appendix. For a panel with N layers of insulating material, the overall R-Value shall be calculated as follows:

eCFR graphic er28de16.007.gif

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Where:

ki is the k factor of the ith material as measured by ASTM C518, (incorporated by reference, see §431.303);

ti is the thickness of the ith material that appears in the panel; and

N is the total number of material layers that appears in the panel.

[81 FR 95803, Dec. 28, 2016]

Appendix C to Subpart R of Part 431—Uniform Test Method for the Measurement of Net Capacity and AWEF of Walk-In Cooler and Walk-In Freezer Refrigeration Systems

1.0   Scope

This appendix covers the test requirements used to determine the net capacity and the AWEF of the refrigeration system of a walk-in cooler or walk-in freezer.

2.0   Definitions

The definitions contained in §431.302 and AHRI 1250-2009 (incorporated by reference; see §431.303) apply to this appendix. When definitions in standards incorporated by reference are in conflict or when they conflict with this section, the hierarchy of precedence shall be in the following order: §431.302, AHRI 1250-2009, and then either AHRI 420-2008 (incorporated by reference; see §431.303) for unit coolers or ASHRAE 23.1-2010 (incorporated by reference; see §431.303) for dedicated condensing units.

3.0   Test Methods, Measurements, and Calculations

Determine the Annual Walk-in Energy Factor (AWEF) and net capacity of walk-in cooler and walk-in freezer refrigeration systems by conducting the test procedure set forth in AHRI 1250-2009 (incorporated by reference; see §431.303), with the modifications to that test procedure provided in this section. When standards that are incorporated by reference are in conflict or when they conflict with this section, the hierarchy of precedence shall be in the following order: §431.302, AHRI 1250-2009, and then either AHRI 420-2008 (incorporated by reference; see §431.303) or ASHRAE 23.1-2010 (incorporated by reference; see §431.303).

3.1. General modifications: Test Conditions and Tolerances.

When conducting testing in accordance with AHRI 1250-2009 (incorporated by reference; see §431.303), the following modifications must be made.

3.1.1. In Table 1, Instrumentation Accuracy, refrigerant temperature measurements shall have a tolerance of ±0.5 F for unit cooler in/out, ±1.0 F for all other temperature measurements.

3.1.2. In Table 2, Test Operating and Test Condition Tolerances for Steady-State Test, electrical power frequency shall have a Test Condition Tolerance of 1 percent.

3.1.3. In Table 2, the Test Operating Tolerances and Test Condition Tolerances for Air Leaving Temperatures shall be deleted.

3.1.4. In Tables 2 through 14, the Test Condition Outdoor Wet Bulb Temperature requirement and its associated tolerance apply only to units with evaporative cooling.

3.1.5. Tables 15 and 16 shall be modified to read as follows:

Table 15—Refrigerator Unit Cooler

Test
description
Unit cooler air entering
dry-bulb, °F
Unit cooler air entering
relative
humidity, %
Saturated
suction temp, °F
Liquid inlet saturation temp, °FLiquid inlet subcooling temp, °FCompressor
capacity
Test objective
Off Cycle Fan Power35<50Compressor OffMeasure fan input power during compressor off cycle.
Refrigeration Capacity Suction A35<50251059Compressor OnDetermine Net Refrigeration Capacity of Unit Cooler.
Refrigeration Capacity Suction B35<50201059Compressor OnDetermine Net Refrigeration Capacity of Unit Cooler.

Note: Superheat to be set according to equipment specification in equipment or installation manual. If no superheat specification is given, a default superheat value of 6.5 °F shall be used. The superheat setting used in the test shall be reported as part of the standard rating.

Table 16—Freezer Unit Cooler

Test
description
Unit cooler air entering
dry-bulb, °F
Unit cooler air entering
relative
humidity, %
Saturated
suction temp, °F
Liquid inlet saturation temp, °FLiquid inlet subcooling temp, °FCompressor
capacity
Test objective
Off Cycle Fan Power−10<50Compressor OffMeasure fan input power during compressor off cycle.
Refrigeration Capacity Suction A−10<50−201059Compressor OnDetermine Net Refrigeration Capacity of Unit Cooler.
Refrigeration Capacity Suction B−10<50−261059Compressor OnDetermine Net Refrigeration Capacity of Unit Cooler.
Defrost−10VariousCompressor OffTest according to Appendix C Section C11.

Note: Superheat to be set according to equipment specification in equipment or installation manual. If no superheat specification is given, a default superheat value of 6.5 °F shall be used. The superheat setting used in the test shall be reported as part of the standard rating.

3.2. General Modifications: Methods of Testing

When conducting testing in accordance with appendix C of AHRI 1250-2009 (incorporated by reference; see §431.303), the following modifications must be made.

3.2.1. In appendix C, section C3.1.6, any refrigerant temperature measurements upstream and downstream of the unit cooler may use sheathed sensors immersed in the flowing refrigerant instead of thermometer wells.

3.2.2. It is not necessary to perform composition analysis of refrigerant (appendix C, section C3.3.6) or refrigerant oil concentration testing (appendix C, section C3.4.6).

3.2.3. In appendix C, section C3.4.5, for verification of sub-cooling downstream of mass flow meters, only the sight glass and a temperature sensor located on the tube surface under the insulation are required.

3.2.4. In appendix C, section C3.5, regarding unit cooler fan power measurements, for a given motor winding configuration, the total power input shall be measured at the highest nameplate voltage. For three-phase power, voltage imbalances shall be no more than 2 percent from phase to phase.

3.2.5. In the test setup (appendix C, section C8.3), the liquid line and suction line shall be constructed of pipes of the manufacturer-specified size. The pipe lines shall be insulated with a minimum total thermal resistance equivalent to 12 -inch thick insulation having a flat-surface R-Value of 3.7 ft2- °F-hr/Btu per inch or greater. Flow meters need not be insulated but must not be in contact with the floor. The lengths of the connected liquid line and suction line shall be 25 feet ± 3 inches, not including the requisite flow meters, each. Of this length, no more than 15 feet shall be in the conditioned space. Where there are multiple branches of piping, the maximum length of piping applies to each branch individually as opposed to the total length of the piping.

3.3. Matched systems, single-package dedicated systems, and unit coolers tested alone: Use the test method in AHRI 1250-2009 (incorporated by reference; see §431.303), appendix C as the method of test for matched refrigeration systems, single-package dedicated systems, or unit coolers tested alone, with the following modifications:

3.3.1. For unit coolers tested alone, use test procedures described in AHRI 1250-2009 (incorporated by reference; see §431.303) for testing unit coolers for use in mix-match system ratings, except that for the test conditions in Tables 15 and 16, use the Suction A saturation condition test points only. Also for unit coolers tested alone, use the calculations in section 7.9 to determine AWEF and net capacity described in AHRI 1250-2009 for unit coolers matched to parallel rack systems.

3.3.2. In appendix C, section C.13, the version of AHRI Standard 420 used for test methods, requirements, and procedures shall be AHRI 420-2008 (incorporated by reference; see §431.303).

3.3.3. Use appendix C, section C10 of AHRI 1250-2009 for off-cycle evaporator fan testing, with the exception that evaporator fan controls using periodic stir cycles shall be adjusted so that the greater of a 50% duty cycle (rather than a 25% duty cycle) or the manufacturer default is used for measuring off-cycle fan energy. For adjustable-speed controls, the greater of 50% fan speed (rather than 25% fan speed) or the manufacturer's default fan speed shall be used for measuring off-cycle fan energy. Also, a two-speed or multi-speed fan control may be used as the qualifying evaporator fan control. For such a control, a fan speed no less than 50% of the speed used in the maximum capacity tests shall be used for measuring off-cycle fan energy.

3.3.4. Use appendix C, section C11 of AHRI 1250-2009 (incorporated by reference, see §431.303) for defrost testing. The Frost Load Condition Defrost Test (C11.1.1) is optional.

3.3.4.1. If the frost load condition defrost test is performed:

3.3.4.1.1   Operate the unit cooler at the dry coil conditions as specified in appendix C, section C11.1 to obtain dry coil defrost energy, DFd, in W-h.

3.3.4.1.2   Operate the unit cooler at the frost load conditions as specified in appendix C, sections C11.1 and C11.1.1 to obtain frosted coil defrost energy, DFf, in W-h.

3.3.4.1.3   The number of defrosts per day, NDF, shall be calculated from the time interval between successive defrosts from the start of one defrost to the start of the next defrost at the frost load conditions.

3.3.4.1.4   Use appendix C, equations C13 and C14 in section C11.3 to calculate, respectively, the daily average defrost energy, DF, in W-h and the daily contribution of the load attributed to defrost QDF in Btu.

3.3.4.1.5   The defrost adequacy requirements in appendix C, section C11.3 shall apply.

3.3.4.2   If the frost load test is not performed:

3.3.4.2.1   Operate the unit cooler at the dry coil conditions as specified in appendix C, section C11.1 to obtain dry coil defrost energy, DFd, in W-h.

3.3.4.2.2   The frost load defrost energy, DFf, in W-h shall be equal to 1.05 multiplied by the dry coil energy consumption, DFd, measured using the dry coil condition test in appendix C, section C11.1.

3.3.4.2.3   The number of defrosts per day NDF used in subsequent calculations shall be 4.

3.3.4.2.4   Use appendix C, equation C13 in section C11.3 to calculate the daily average defrost energy, DF, in W-h.

3.3.4.2.5   The daily contribution of the load attributed to defrost QDF in Btu shall be calculated as follows:

eCFR graphic er28de16.008.gif

View or download PDF

Where:

DFd = the defrost energy, in W-h, measured at the dry coil condition

3.3.5. If a unit has adaptive defrost, use appendix C, section C11.2 of AHRI 1250-2009 as follows:

3.3.5.1. When testing to certify to the energy conservation standards in §431.306, do not perform the optional test for adaptive or demand defrost in appendix C, section C11.2.

3.3.5.2. When determining the represented value of the calculated benefit for the inclusion of adaptive defrost, conduct the optional test for adaptive or demand defrost in appendix C, section C11.2 to establish the maximum time interval allowed between dry coil defrosts. If this time is greater than 24 hours, set its value to 24 hours. Then, calculate NDF (the number of defrosts per day) by averaging the time in hours between successive defrosts for the dry coil condition with the time in hours between successive defrosts for the frosted coil condition, and dividing 24 by this average time. (The time between successive defrosts for the frosted coil condition is found as specified in section 3.3.4 of this appendix C of AHRI 1250-2009: That is, if the optional frosted coil test was performed, the time between successive defrosts for the frosted coil condition is found by performing the frosted coil test as specified in section 3.3.4.1 of this appendix; and if the optional frosted coil test was not performed, the time between successive defrosts for the frosted coil condition shall be set to 4 as specified in section 3.3.4.2. of this appendix) Use this new value of NDF in subsequent calculations.

3.3.6. For matched refrigeration systems and single-package dedicated systems, calculate the AWEF using the calculations in AHRI 1250-2009 (incorporated by reference; see §431.303), section 7.4, 7.5, 7.6, or 7.7, as applicable.

3.3.7. For unit coolers tested alone, calculate the AWEF and net capacity using the calculations in AHRI 1250-2009, (incorporated by reference; see §431.303), section 7.9. If the unit cooler has variable-speed evaporator fans that vary fan speed in response to load, then:

3.3.7.1. When testing to certify compliance with the energy conservation standards in §431.306, fans shall operate at full speed during on-cycle operation. Do not conduct the calculations in AHRI 1250-2009, section 7.9.3. Instead, use AHRI 1250-2009, section 7.9.2 to determine the system's AWEF.

3.3.7.2. When calculating the benefit for the inclusion of variable-speed evaporator fans that modulate fan speed in response to load for the purposes of making representations of efficiency, use AHRI 1250-2009, section 7.9.3 to determine the system AWEF.

3.4. Dedicated condensing units that are not matched for testing and are not single-package dedicated systems

3.4.1. Refer to appendix C, section C.12 of AHRI 1250-2009 (incorporated by reference; see §431.303), for the method of test for dedicated condensing units. The version of ASHRAE Standard 23 used for test methods, requirements, and procedures shall be ANSI/ASHRAE Standard 23.1-2010 (incorporated by reference; see §431.303). When applying this test method, use the applicable test method modifications listed in sections 3.1 and 3.2 of this appendix. For the test conditions in AHRI 1250-2009, Tables 11, 12, 13, and 14, use the Suction A condition test points only.

3.4.2. Calculate the AWEF and net capacity for dedicated condensing units using the calculations in AHRI 1250-2009 (incorporated by reference; see §431.303) section 7.8. Use the following modifications to the calculations in lieu of unit cooler test data:

3.4.2.1. For calculating enthalpy leaving the unit cooler to calculate gross capacity, (a) The saturated refrigerant temperature (dew point) at the unit cooler coil exit, Tevap, shall be 25 °F for medium-temperature systems (coolers) and −20 °F for low-temperature systems (freezers), and (b) the refrigerant temperature at the unit cooler exit shall be 35 °F for medium-temperature systems (coolers) and −14 °F for low-temperature systems (freezers). For calculating gross capacity, the measured enthalpy at the condensing unit exit shall be used as the enthalpy entering the unit cooler.

3.4.2.2. The on-cycle evaporator fan power in watts, EFcomp,on, shall be calculated as follows:

For medium-temperature systems (coolers), EFcomp,on = 0.013 × qmix,cd

For low-temperature systems (freezers), EFcomp,on = 0.016 × qmix,cd

Where:

qmix,cd is the gross cooling capacity of the system in Btu/h, found by a single test at the Capacity A, Suction A condition for outdoor units and the Suction A condition for indoor units.

3.4.2.3. The off-cycle evaporator fan power in watts, EFcomp,off, shall be calculated as follows:

EFcomp,off = 0.2 × EFcomp,on

Where:

EF comp,on is the on-cycle evaporator fan power in watts.

3.4.2.4. The daily defrost energy use in watt-hours, DF, shall be calculated as follows:

For medium-temperature systems (coolers), DF = 0

For low-temperature systems (freezers), DF = 8.5 × 10−3 × qmix,cd1.27 × NDF

Where:

qmix,cd is the gross cooling capacity of the system in Btu/h, found by a single test at the Capacity A, Suction A condition for outdoor units and the Suction A condition for indoor units, and

NDF is the number of defrosts per day, equal to 4.

3.4.2.5. The daily defrost heat load contribution in Btu, QDF, shall be calculated as follows:

For medium-temperature systems (coolers), QDF = 0

For low-temperature systems (freezers), QDF = 0.95 × DF × 3.412

Where:

DF is the daily defrost energy use in watt-hours.

3.5   Hot Gas Defrost Refrigeration Systems

For all hot gas defrost refrigeration systems, remove the hot gas defrost mechanical components and disconnect all such components from electrical power.

3.5.1   Hot Gas Defrost Dedicated Condensing Units Tested Alone: Test these units as described in section 3.4 of this appendix for electric defrost dedicated condensing units that are not matched for testing and are not single-package dedicated systems.

3.5.2   Hot Gas Defrost Matched Systems, Single-package Dedicated Systems, and Unit Coolers Tested Alone: Test these units as described in section 3.3 of this appendix for electric defrost matched systems, single-package dedicated systems, and unit coolers tested alone, but do not conduct defrost tests as described in sections 3.3.4 and 3.3.5 of this appendix. Calculate daily defrost energy use as described in section 3.4.2.4 of this appendix. Calculate daily defrost heat contribution as described in section 3.4.2.5 of this appendix.

[81 FR 95803, Dec. 28, 2016]

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