(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: ------------------------------------------------------------------------
Equations for
maximum energy
Class descriptor Class consumption (kWh/
day) *------------------------------------------------------------------------Display Door, Medium DD.M............. 0.04 x Add + 0.41.
Temperature.Display Door, Low Temperature. DD.L............. 0.15 x 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: ------------------------------------------------------------------------
Equations for
maximum energy
Class descriptor Class consumption (kWh/
day) *------------------------------------------------------------------------Passage door, Medium PD.M............. 0.05 x And + 1.7.
Temperature.Passage Door, Low Temperature. PD.L............. 0.14 x And + 4.8.Freight Door, Medium FD.M............. 0.04 x And + 1.9.
Temperature.Freight Door, Low Temperature. FD.L............. 0.12 x And + 5.6.------------------------------------------------------------------------*And represents the surface area of the non-display door.
(e) Walk-in cooler and freezer refrigeration systems. All walk-in cooler and walk-in freezer refrigeration systems manufactured starting on June 5, 2017, must satisfy the following standards: ------------------------------------------------------------------------
Equations for minimum
Class descriptor Class AWEF (Btu/W-h)*------------------------------------------------------------------------Dedicated Condensing, Medium DC.M.I, <9,000.. 5.61
Temperature, Indoor System,
<9,000 Btu/h Capacity.Dedicated Condensing, Medium DC.M.I, =9,000.
=9,000 Btu/h
Capacity.Dedicated Condensing, Medium DC.M.O, <9,000.. 7.60
Temperature, Outdoor System,
<9,000 Btu/h Capacity.Dedicated Condensing, Medium DC.M.O, =9,000.
=9,000 Btu/h
Capacity.Dedicated Condensing, Low DC.L.I, <9,000.. 5.93 x 10-\5\ x Q +
Temperature, Indoor System, 2.33
<9,000 Btu/h Capacity.Dedicated Condensing, Low DC.L.I, =9,000.
=9,000 Btu/h
Capacity.Dedicated Condensing, Low DC.L.O, <9,000.. 2.30 x 10-\4\ x Q +
Temperature, Outdoor System, 2.73
<9,000 Btu/h Capacity.Dedicated Condensing, Low DC.L.O, =9,000.
=9,000 Btu/h
Capacity.
Multiplex Condensing, Medium MC.M............ 10.89
Temperature.Multiplex Condensing, Low MC.L............ 6.57
Temperature.------------------------------------------------------------------------* Q represents the system gross capacity as calculated by the procedures
set forth in AHRI 1250. [74 FR 12074, Mar. 23, 2009, as amended at 78 FR 62993, Oct. 23, 2013; 79 FR 32123, June 3, 2014]
Sec. 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 Sec. 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 Core region means the part of the panel that is not the edge region.
3.3 Edge region means a region of the panel that is wide enough to encompass any framing members and edge effects. 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 2 in. 0.25 in. If the panel does not contain framing members then the width of the edge region must be 4 in 0.25 in. For walk-in panels that utilize vacuum insulated panels (VIP) for insulation, the width of the edge region must be the lesser of 4.5 in. 1 in. or the maximum width that does not cause the VIP to be pierced by the cutting device when the edge region is cut.
3.4 Surface area means the area of the surface of the walk-in component that would be external to the walk-in. For example, for panel, the surface area would be the area of the side of the panel that faces the outside of the walk-in. It would not include edges of the panel that are not exposed to the outside of the walk-in.
3.5 Rating conditions means, unless explicitly stated otherwise, all conditions shown in Table A.1. For installations where two or more walk-in envelope components share any surface(s), the ``external conditions'' of the shared surface(s) must reflect the internal conditions of the adjacent walk-in. For example, if a walk-in component divides a walk-in freezer from a walk-in cooler, then the internal conditions are the freezer rating conditions and the external conditions are the cooler rating conditions.
3.6 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 Temperature................... 35 [deg]F.Freezer Dry Bulb Temperature.................. -10 [deg]F.------------------------------------------------------------------------
External Temperatures (space external to the envelope)------------------------------------------------------------------------Freezer and Cooler Dry Bulb Temperatures...... 75 [deg]F.------------------------------------------------------------------------
Subfloor Temperatures------------------------------------------------------------------------Freezer and Cooler Dry Bulb Temperatures...... 55 [deg]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-ft\2\- [deg]F.
(b) Calculate the display panel surface area, as defined in section 3.4 of this appendix, Adp, ft\2\, with standard geometric formulas or engineering software.
(c) Calculate the temperature differential, [Delta]Tdp, [deg]F, for the display panel, as follows:[GRAPHIC] [TIFF OMITTED] TR09JN11.003 Where:TDB,ext,dp = dry-bulb air external temperature, [deg]F, as
prescribed in Table A.1; and TDB,int,dp = dry-bulb air temperature internal to the cooler
or freezer, [deg]F, as prescribed in Table A.1.
(d) Calculate the conduction load through the display panel, Qcond-dp, Btu/h, as follows:[GRAPHIC] [TIFF OMITTED] TR09JN11.004 Where:Adp = surface area of the walk-in display panel, ft\2\;[Delta]Tdp = temperature differential between refrigerated
and adjacent zones, [deg]F; andUdp = thermal transmittance, U-factor, of the display panel
in accordance with section 5.3 of this appendix, Btu/h-ft\2\-
[deg]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:[GRAPHIC] [TIFF OMITTED] TR09JN11.005 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-ft\2\- [deg]F
(b) Calculate the surface area, as defined in section 3.4 of this appendix, of the display door, Add, ft\2\, with standard geometric formulas or engineering software.
(c) Calculate the temperature differential, [Delta]Tdd, [deg]F, for the display door as follows:[GRAPHIC] [TIFF OMITTED] TR09JN11.020 Where: TDB,ext, dd = dry-bulb air temperature external to the
display door, [deg]F, as prescribed in Table A.1; andTDB,int, dd = dry-bulb air temperature internal to the
display door, [deg]F, as prescribed in Table A.1.
(d) Calculate the conduction load through the display doors, Qcond-dd, Btu/h, as follows:[GRAPHIC] [TIFF OMITTED] TR09JN11.021 Where: [Delta]Tdd = temperature differential between refrigerated
and adjacent zones, [deg]F;Add = surface area walk-in display doors, ft\2\; andUdd = thermal transmittance, U-factor of the door, in
accordance with section 5.3 of this appendix, Btu/h-ft\2\-
[deg]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:[GRAPHIC] [TIFF OMITTED] TR09JN11.022 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, %; andnu,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:[GRAPHIC] [TIFF OMITTED] TR09JN11.023 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; andPdd-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:[GRAPHIC] [TIFF OMITTED] TR09JN11.024 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:[GRAPHIC] [TIFF OMITTED] TR09JN11.025 Where: EER = EER of walk-in cooler or walk-in freezer, Btu/W-h; andPdd-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:[GRAPHIC] [TIFF OMITTED] TR09JN11.026 Where: Qcond, dd = the conduction load through the display door,
Btu/h; andEER = EER of walk-in (cooler or freezer), Btu/W-h.
(c) Calculate the total energy, Edd,tot, kWh/day,
[GRAPHIC] [TIFF OMITTED] TR09JN11.027
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; andCdd-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, ft\2\, with standard geometric formulas or with engineering software.
(b) Calculate the temperature differential of the non-display door, [Delta]Tnd, [deg]F, as follows:[GRAPHIC] [TIFF OMITTED] TR09JN11.028 Where: TDB,ext, nd = dry-bulb air external temperature, [deg]F, as
prescribed by Table A.1; andTDB,int, nd = dry-bulb air internal temperature, [deg]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, [GRAPHIC] [TIFF OMITTED] TR09JN11.029 Where: [Delta]Tnd = temperature differential across the non-display
door, [deg]F;Und = thermal transmittance, U-factor of the door, in
accordance with section 5.3 of this appendix, Btu/h-ft\2\-
[deg]F; andAnd = area of non-display door, ft\2\. 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:[GRAPHIC] [TIFF OMITTED] TR09JN11.030 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, %; andnu,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:[GRAPHIC] [TIFF OMITTED] TR09JN11.031 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; andPnd-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:[GRAPHIC] [TIFF OMITTED] TR09JN11.032 Where: Pnd-tot,int = the total interior electrical energy usage for
the non-display door, of type t, kWh/day; andPnd-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:[GRAPHIC] [TIFF OMITTED] TR09JN11.033 Where: EER = EER of walk-in cooler or freezer, Btu/W-h; andPnd-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:[GRAPHIC] [TIFF OMITTED] TR09JN11.034 Where: Qcond-nd = the conduction load through the non-display door,
Btu/hr; andEER = EER of walk-in (cooler or freezer), Btu/W-h.
(c) Calculate the total energy, End,tot, kWh/day, as follows:[GRAPHIC] [TIFF OMITTED] TR09JN11.035 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;
andCnd-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 [Reserved]
5.2 [Reserved]
5.3 U-factor of Doors and Display Panels
(a) Follow the procedure in NFRC 100, (incorporated by reference; see Sec. 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/m\2\*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/m\2\*K) 5%.
(2) Cold-side conditions:
(i) Air temperature of 35 [deg]F (1.7 [deg]C) for cooler doors and -10 [deg]F (-23.3 [deg]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 [deg]F (23.9 [deg]C)
(ii) Mean outside radiant temperature must be the same as section 5.3(a)(3)(i), above.
(4) Direct solar irradiance = 0 W/m\2\ (Btu/h-ft\2\).
(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]