(a) Scope. This section provides test procedures for measuring, pursuant to EPCA, the energy consumption of walk-in coolers and walk-in freezers.
(b) This paragraph (b) shall be used for the purposes of certifying compliance with the applicable R-value energy conservation standards for panels until compliance with amended standards is required.
(1) The R value shall be the 1/K factor multiplied by the thickness of the panel.
(2) The K factor shall be based on ASTM C518 (incorporated by reference, see Sec. 431.303).
(3) When 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) When 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.
(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 Sec. 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.
(6) Internal non-foam member and/or edge regions shall not be considered in ASTM C518 testing.
(7) For panels consisting of two or more layers of dissimilar insulating materials (excluding facers or protective skins), test each material as described in paragraphs (c)(1) through (6) of this section. For a panel with N layers of insulating material, the overall R-Value shall be calculated as follows:[GRAPHIC] [TIFF OMITTED] TR13MY14.008
Where:
ki is the k factor of the ith material as measured by ASTM C518,
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.
(c) This paragraph (c) shall be used for any representations of energy efficiency or energy use starting on October 12, 2011, and to certify compliance to the energy conservation standards of the R-value of panels on or after the compliance date of amended energy conservation standards for walk-in cooler and freezers.
(1) The R value shall be the 1/K factor multiplied by the thickness of the panel.
(2) The K factor shall be based on ASTM C518 (incorporated by reference; see Sec. 431.303).
(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) 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.
(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 Sec. 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.
(6) Internal non-foam member and/or edge regions shall not be considered in ASTM C518 testing.
(7) For panels consisting of two or more layers of dissimilar insulating materials (excluding facers or protective skins), test each material as described in paragraphs (c)(1) through (6) of this section. For a panel with N layers of insulating material, the overall R-Value shall be calculated as follows: [GRAPHIC] [TIFF OMITTED] TR13MY14.009
Where:
ki is the k factor of the ith material as measured by ASTM C518, and
ti is the thickness of the ith material that appears in the panel.
N is the total number of material layers that appears in the panel.
(8) 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 section 4.1.
(9) 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, sections 4.4 and 4.5, respectively.
(10) Determine the Annual Walk-in Energy Factor 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 Sec. 431.303), with the following modifications:
(i) 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. Also, refrigerant temperature measurements shall have a tolerance of 0.5 F for unit cooler in/out, 1.0 F for all other temperature measurements.
(ii) In Table 2, the Test Operating Tolerances and Test Condition Tolerances for Air Leaving Temperatures shall be deleted.
(iii) In Tables 2 through 14, The Test Condition Outdoor Wet Bulb Temperature requirement and its associated tolerance apply only to units with evaporative cooling.
(iv) In section C3.1.6, refrigerant temperature measurements upstream and downstream of the unit cooler may use sheathed sensors immersed in the flowing refrigerant instead of thermometer wells.
(v) In section C3.5, 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.
(vi) In the test setup (section C8.3), the condenser and unit cooler shall be connected by pipes of the manufacturer-specified size. The pipe lines shall be insulated with a minimum total thermal resistance equivalent to \1/2\[sec] thick insulation having a flat-surface R-Value of 3.7 ft\2\- [deg]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, not including the requisite flow meters, each. Of this length, no more than 15 feet shall be in the conditioned space. In the case 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.
(vii) In 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.
(viii) Delete section C3.3.6.
(ix) In section C11.1, to determine frost load defrost conditions, the Frost Load Conditions Defrost Test (C11.1.1) is optional. If the frost load test is not performed, the frost load defrost DFf shall be equal to 1.05 multiplied by the dry coil energy consumption DFd measured using the dry coil condition test in section C11.1 and the number of defrosts per day NDF shall be set to 4.
(x) In section C11.2, if the system has an adaptive or demand defrost system, the optional test may be run as specified to establish the number of defrosts per day under dry coil conditions and this number shall be averaged with the number of defrosts per day calculated under the frost load conditions. If the system has an adaptive or demand defrost system and the optional test is not run, the number of defrosts per day NDF shall be set to the average of 1 and the number of defrosts per day calculated under the frost load conditions (paragraph (c)(8)(ix) of this section).
(xi) In section C11.3, if the frost load test is not performed, the daily contribution of the load attributed to defrost QDF in Btu shall be calculated as follows:[GRAPHIC] [TIFF OMITTED] TR13MY14.010
Where: DFd = the defrost energy, in W-h, at the dry coil conditionDFf = the defrost energy, in W-h, at the frosted coil
conditionNDF = the number of defrosts per day
(xii) In section C11, if the unit utilizes hot gas defrost, QDF and DF shall be calculated as follows: QDF = 0.18 Btu/defrost per Btu/h capacity x Qref x NDF
Where: Qref = Gross refrigeration capacity in Btu/h as measured at
the high ambient condition (90 [deg]F for indoor systems and 95
[deg]F for outdoor systems)NDF = Number of defrosts per day; this value shall be set to
the number recommended in the installation instructions for the unit
(or if no instructions, shall be set to 4) for units without
adaptive defrost and 2.5 for units with adaptive defrostFor unit coolers connected to a multiplex system: The defrost energy,
DF, in W-h = 0
For dedicated condensing systems or condensing units tested separately: DF = 0.5 x QDF/3.412 Btu/W-h
(xiii) Delete section C3.4.6.
(xiv) Off-cycle evaporator fan test. In lieu of section C10, follow the following procedures: Upon the completion of the steady state test for walk-in systems, the compressors of the walk-in systems shall be turned off. The unit cooler's fans' power consumption shall be measured in accordance with the requirements in Section C3.5. Off-cycle fan power shall be equal to on-cycle fan power unless evaporator fans are controlled by a qualifying control. Qualifying evaporator fan controls shall have a user adjustable method of destratifying air during the off-cycle including but not limited to: adjustable fan speed control or periodic ``stir cycles.'' Qualifying evaporator fan controls shall be adjusted so that the greater of a 50% duty cycle or the manufacturer default is used for measuring off-cycle fan energy. For variable speed controls, the greater of 50% fan speed or the manufacturer's default fan speed shall be used for measuring off-cycle fan energy. When a cyclic control is used at least three full ``stir cycles'' are measured.
(xv) In lieu of Table 15 and Table 16, use the following Tables:
Table 15--Refrigerator Unit Cooler--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit cooler Unit cooler Liquid Liquid
air air Saturated inlet inlet
Test description entering entering suction saturation subcooling Compressor capacity Test objective
dry-bulb, relative temp, temp, temp,
[deg]F humidity, % [deg]F [deg]F [deg]F--------------------------------------------------------------------------------------------------------------------------------------------------------Off Cycle Fan Power.................. 35 <50 -- -- -- Compressor Off.......... Measure fan input power
during compressor off
cycle.Refrigeration Capacity Suction A..... 35 <50 25 105 9 Compressor On........... Determine Net
Refrigeration Capacity
of Unit Cooler.Refrigeration Capacity Suction B..... 35 <50 20 105 9 Compressor On........... Determine 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 [deg]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--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit cooler Unit cooler Liquid Liquid
air air Saturated inlet inlet
Test Description entering entering suction saturation subcooling Compressor capacity Test objective
dry-bulb, relative temp, temp, temp,
[deg]F humidity, % [deg]F [deg]F [deg]F--------------------------------------------------------------------------------------------------------------------------------------------------------Off Cycle Fan Power.................. -10 <50 -- -- -- Compressor Off.......... Measure fan input power
during compressor off
cycle.Refrigeration Capacity Suction A..... -10 <50 25 105 9 Compressor On........... Determine Net
Refrigeration Capacity
of Unit Cooler.Refrigeration Capacity Suction B..... -10 <50 20 105 9 Compressor On........... Determine Net
Refrigeration Capacity
of Unit Cooler.Defrost.............................. -10 Various -- -- -- Compressor Off.......... Test 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 [deg]F shall be used. The superheat setting used in the test shall be reported as part of the standard rating.
(11) Determine the annual energy consumption of walk-in cooler and walk-in freezer refrigeration systems:
(i) For systems consisting of a packaged dedicated system or a split dedicated system, where the condensing unit is located outdoors, by conducting the test procedure set forth in AHRI 1250 and recording the annual energy consumption term in the equation for annual walk-in energy factor in section 7 of AHRI 1250:[GRAPHIC] [TIFF OMITTED] TR09JN11.000 where tj and n represent the outdoor temperature at each bin
j and the number of hours in each bin j, respectively, for the
temperature bins listed in Table D1 of AHRI 1250.
(ii) For systems consisting of a packaged dedicated system or a split dedicated system where the condensing unit is located in a conditioned space, by performing the following calculation:[GRAPHIC] [TIFF OMITTED] TR09JN11.001 where BLLH and BLLL for refrigerator and freezer systems are defined in
sections 6.2.1 and 6.2.2, respectively, of AHRI 1250 and the
annual walk-in energy factor is calculated from the results of
the test procedures set forth in AHRI 1250.
(iii) For systems consisting of a single unit cooler or a set of multiple unit coolers serving a single piece of equipment and connected to a multiplex condensing system, by performing the following calculation:[GRAPHIC] [TIFF OMITTED] TR09JN11.002 where BLLH and BLLL for refrigerator and freezer systems are defined in
section 7.9.2.2 and 7.9.2.3, respectively, of AHRI 1250 and
the annual walk-in energy factor is calculated from the
results of the test procedures set forth in AHRI 1250.
(12) Calculation of AWEF for a walk-in cooler and freezer refrigeration system component distributed individually. This section only applies to fixed capacity condensing units. Multiple-capacity condensing units must be tested as part of a matched system.
(i) Calculate the AWEF for a refrigeration system containing a unit cooler that is distributed individually using the method for testing a unit cooler connected to a multiplex condensing system.
(ii) Calculate the AWEF for a refrigeration system containing a condensing unit that is distributed individually using the following nominal values: Saturated suction temperature at the evaporator coil exit
Tevap ( [deg]F) = 25 for coolers and -20 for freezersFor medium temperature (cooler) condensing units: On-cycle evaporator
fan power EFcomp, on (W) = 0.013 W-h/Btu x
qmix, cd (Btu/h); where qmix, cd is the gross
cooling capacity at the highest ambient rating condition (90[emsp14]
[deg]F for indoor units and 95[emsp14] [deg]F for outdoor units)For low temperature (freezer) condensing units: On-cycle evaporator fan
power EFcomp, on (W) = 0.016 W-h/Btu x
qmix, cd (Btu/h); where qmix, cd is the gross
cooling capacity at the highest ambient rating condition (90[emsp14]
[deg]F for indoor units and 95[emsp14] [deg]F for outdoor units)Off-cycle evaporator fan power EFcomp, off (W) = 0.2 x
EFcomp, on (W)For medium temperature (cooler) condensing units: Daily defrost energy
use DF (W-h) = 0 and daily defrost heat load contribution
QDF (Btu) = 0
For low temperature (freezer) condensing units without hot gas defrost capability: Daily defrost energy use DF (W-h) = 8.5 x 10-3 x
(qmix, cd (Btu/h))\1.27\ x NDF for freezersDefrost heat load contribution QDF (Btu) = 0.95 x DF (W-h)/
3.412 Btu/W-h
For low temperature (freezer) condensing units with hot gas defrost capability, DF and QDF shall be calculated using the method in paragraph (c)(10)(xii) of this section.
The number of defrost cycles per day (NDF) shall be set to the number recommended in the installation instructions for the unit (or if no instructions, shall be set to 2.5). [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] Sec. 431.305 [Reserved]
Energy Conservation Standards