ASTM F2473-12(2023)

Standard Test Method for Performance of Water-Bath Rethermalizers

SIGNIFICANCE AND USE
5.1 The energy input rate test is used to confirm that the water-bath rethermalizer under test is operating in accordance with its nameplate rating.  
5.2 The water-bath rethermalizer temperature calibration is used to ensure that the water-bath rethermalizer being tested is operating at the specified temperature. Temperature calibration also can be used to evaluate and calibrate the thermostat control dial(s).  
5.3 Preheat energy and time can be useful to food service operators to manage energy demands, and to estimate the amount of time required for preheating a water-bath rethermalizer.  
5.4 Idle energy rate and pilot energy rate can be used to estimate energy consumption during non-rethermalizing periods.  
5.5 Production capacity is used by food service operators to choose a water-bath rethermalizer that matches their particular food output requirements.  
5.6 Retherm-energy efficiency is a precise indicator of the water bath rethermalizer’s energy performance under full-load condition. This information enables the operator to consider energy performance when selecting a water-bath rethermalizer.
SCOPE
1.1 This test method covers the energy consumption and rethermalizing performance of floor-model and countertop water-bath rethermalizers. The food service operator can use this evaluation to select a water-bath rethermalizer and understand its energy consumption and production capacity.  
1.2 This test method is applicable to floor and countertop model gas and electric units.  
1.3 The water-bath rethermalizer can be evaluated with respect to the following (where applicable):  
1.3.1 Energy input rate (10.2),  
1.3.2 Preheat energy consumption, time, and rate (10.4),  
1.3.3 Idle energy rate (10.5),  
1.3.4 Pilot energy rate (10.6),  
1.3.5 Retherm energy rate (10.8),  
1.3.6 Production capacity (10.8), and  
1.3.7 Retherm-energy efficiency (10.8).  
1.4 This test method is not intended to answer all performance criteria in the evaluation and selection of a water-bath rethermalizer.  
1.5 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.  
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-May-2023
• ICS: 91.040.20 - Buildings for commerce and industry
• Technical Committee: F26 - Food Service Equipment
• Drafting Committee: F26.06 - Productivity and Energy Protocol

Relations

• Refers: ASTM D3588-98(2011) - Standard Practice for Calculating Heat Value, Compressibility Factor, and Relative Density of Gaseous Fuels
• Effective Date: 01-Nov-2011
• Refers: ASTM D3588-98(2003) - Standard Practice for Calculating Heat Value, Compressibility Factor, and Relative Density of Gaseous Fuels
• Effective Date: 10-May-2003
• Refers: ASTM D3588-98 - Standard Practice for Calculating Heat Value, Compressibility Factor, and Relative Density of Gaseous Fuels
• Effective Date: 10-May-1998

Overview

ASTM F2473-12(2023): Standard Test Method for Performance of Water-Bath Rethermalizers provides a comprehensive procedure to evaluate the energy consumption and rethermalizing performance of floor-model and countertop water-bath rethermalizers used in commercial and institutional food service settings. This standard, developed by the ASTM Committee F26 on Food Service Equipment, supports food service operators and equipment manufacturers in making informed decisions regarding the selection, operation, and benchmarking of water-bath rethermalizers. The test method is applicable to both gas and electric models, ensuring broad industry relevance.

Key Topics

• Energy Input Rate: Verifies that the rethermalizer operates in accordance with its nameplate energy rating. This ensures compliance with manufacturer specifications and supports accurate equipment comparisons.
• Temperature Calibration: Assures that the rethermalizer maintains the specified water temperature, which is critical for both food safety and consistent culinary results. This section also aids in calibrating thermostat controls.
• Preheat Energy and Time: Evaluates the energy and time required for the unit to reach operating temperature from ambient. This data enables food service operators to plan for startup periods and energy budgeting.
• Idle and Pilot Energy Rate: Measures energy consumption when the unit is not actively rethermalizing, offering insights into operational efficiency during standby periods.
• Production Capacity: Determines the maximum rate at which the rethermalizer can heat food, assisting operators in selecting equipment based on output needs.
• Retherm-Energy Efficiency: Provides a key performance metric showing how efficiently the unit transfers energy to the food during a typical full-load rethermalizing cycle.

Applications

• Food Service Equipment Selection: Using the objectively measured parameters in ASTM F2473-12(2023), food service operators can identify water-bath rethermalizers that best match their required production capacities and energy targets.
• Operational Cost Management: Idle and pilot energy rates, as well as preheat energy metrics, provide actionable data for energy conservation and budgeting in kitchens.
• Regulatory Compliance and Consistency: By following a standardized test method, manufacturers and commercial kitchens can ensure consistency in equipment performance reporting, supporting regulatory, safety, and procurement standards.
• Maintenance and Calibration: Routine verification using this standard can identify when recalibration or maintenance is needed, helping maintain optimal operation and energy efficiency.

Related Standards

• ASTM D3588: Practice for Calculating Heat Value, Compressibility Factor, and Relative Density of Gaseous Fuels - referenced for determining gas energy input.
• ANSI Z83.11: Gas Food Service Equipment - related to safety and performance requirements for commercial gas appliances.
• ASHRAE Handbook of Fundamentals: Referenced for thermodynamic properties and measuring practices relevant to food service appliances.
• NSF/ANSI 4: Commercial Cooking, Rethermalization, and Powered Hot Food Holding and Transport Equipment - provides sanitary and performance requirements for commercial kitchen equipment.

Practical Value

ASTM F2473-12(2023) enables standardized testing of water-bath rethermalizers, facilitating the reliable comparison of equipment models for energy efficiency, production throughput, and operational consistency. By quantifying key metrics like energy input rate, temperature stability, and production capacity, stakeholders can make informed procurement and operational decisions that enhance food safety, energy savings, and cost efficiency in commercial kitchen environments.

Keywords: water-bath rethermalizers, energy efficiency, food service equipment, rethermalizing performance, production capacity, ASTM F2473, commercial kitchen standards, equipment testing.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: F2473 − 12 (Reapproved 2023) An American National Standard
Standard Test Method for
Performance of Water-Bath Rethermalizers
This standard is issued under the fixed designation F2473; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
1.1 This test method covers the energy consumption and 2.1 ASTM Standards:
D3588 Practice for Calculating Heat Value, Compressibility
rethermalizing performance of floor-model and countertop
Factor, and Relative Density of Gaseous Fuels
water-bath rethermalizers. The food service operator can use
2.2 ANSI Standard:
this evaluation to select a water-bath rethermalizer and under-
ANSI Z83.11 Gas Food Service Equipment
stand its energy consumption and production capacity.
2.3 ASHRAE Documents:
1.2 This test method is applicable to floor and countertop
ASHRAE Handbook of Fundamentals Chapter 6, Table
model gas and electric units.
2—Thermodynamic; Chapter 6, Table
1.3 The water-bath rethermalizer can be evaluated with 2—Thermodynamic Properties of Water at Saturation
respect to the following (where applicable):
ASHRAE Guideline 2-1986 (RA90) Engineering Analysis
1.3.1 Energy input rate (10.2), of Experimental Data
2.4 NSF Standards:
1.3.2 Preheat energy consumption, time, and rate (10.4),
NSF Listing-Food Equipment and Related, Components and
1.3.3 Idle energy rate (10.5),
Material
1.3.4 Pilot energy rate (10.6),
NSF/ANSI 4 Commercial Cooking, Rethermalization and
1.3.5 Retherm energy rate (10.8),
Powered Hot Food Holding and Transport Equipment
1.3.6 Production capacity (10.8), and
1.3.7 Retherm-energy efficiency (10.8).
3. Terminology
1.4 This test method is not intended to answer all perfor-
3.1 Definitions:
mance criteria in the evaluation and selection of a water-bath
3.1.1 auto-fill, n—water height sensor device that activates a
rethermalizer.
fresh water fill solenoid when the water level in the rethermal-
izer drops below a predetermined height.
1.5 The values stated in inch-pound units are to be regarded
3.1.2 energy input rate, n—peak rate at which a water-bath
as the standard. The values given in parentheses are for
rethermalizer consumes energy (Btu/h (kJ/h) or kW).
information only.
3.1.3 idle energy rate, n—average rate of energy consumed
1.6 This standard does not purport to address all of the
(Btu/h or kW) by the rethermalizer while holding or maintain-
safety concerns, if any, associated with its use. It is the
ing the water vat at the thermostat(s) set point.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
3.1.4 over-flow drain, n—drain for eliminating the excess
mine the applicability of regulatory limitations prior to use.
foam and starch created during the rethermalizing process.
1.7 This international standard was developed in accor-
3.1.5 pilot energy rate, n—average rate of energy consump-
dance with internationally recognized principles on standard-
tion (Btu/h (kJ/h)) by a water-bath rethermalizer’s continuous
ization established in the Decision on Principles for the
pilot (if applicable).
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Barriers to Trade (TBT) Committee.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
This test method is under the jurisdiction of ASTM Committee F26 on Food 4th Floor, New York, NY 10036.
Service Equipment and is the direct responsibility of Subcommittee F26.06 on Available from American Society of Heating, Refrigerating, and Air-
Productivity and Energy Protocol. Conditioning Engineers, Inc. (ASHRAE), 1791 Tullie Circle, NE, Atlanta, GA
Current edition approved June 1, 2023. Published July 2023. Originally approved 30329.
in 2005. Last previous edition approved in 2018 as F2473 – 12 (2018). DOI: Available from NSF International, P.O. Box 130140, 789 N. Dixboro Rd., Ann
10.1520/F2473-12R23. Arbor, MI 48113-0140.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F2473 − 12 (2023)
3.1.6 preheat energy, n—amount of energy consumed (Btu 4.5 Energy consumption and time are monitored while the
or kWh) by the rethermalizer while heating the water vat from water-bath rethermalizer is used to reheat three full loads of
ambient room temperature to the calibrated thermostat(s) set refrigerated, prepackaged clam chowder soup. Retherm-energy
point. efficiency, retherm energy rate, and production capacity are
determined from these tests.
3.1.7 preheat rate, n—average rate (°F/min) at which the
water vat temperature is heated from ambient temperature to
5. Significance and Use
the rethermalizer’s calibrated thermostat(s) set point.
5.1 The energy input rate test is used to confirm that the
3.1.8 preheat time, n—time required for the water vat to heat
water-bath rethermalizer under test is operating in accordance
from ambient room temperature to the calibrated thermostat(s)
with its nameplate rating.
set point.
3.1.9 production capacity, n—maximum rate (lb/h (kg/h)) at
5.2 The water-bath rethermalizer temperature calibration is
which water-bath rethermalizer can bring the refrigerated clam
used to ensure that the water-bath rethermalizer being tested is
chowder to a specified rethermalized condition.
operating at the specified temperature. Temperature calibration
also can be used to evaluate and calibrate the thermostat
3.1.10 retherm energy, n—total energy consumed by the
control dial(s).
rethermalizer as it is used to reheat bags of refrigerated clam
chowder.
5.3 Preheat energy and time can be useful to food service
3.1.11 retherm-energy effıciency, n—quantity of energy re- operators to manage energy demands, and to estimate the
quired to warm the specified food product (clam chowder
amount of time required for preheating a water-bath rethermal-
soup), expressed as a percentage of the quantity of energy input izer.
to the water-bath rethermalizer during the reheating period.
5.4 Idle energy rate and pilot energy rate can be used to
3.1.12 retherm energy rate, n—average rate of energy con-
estimate energy consumption during non-rethermalizing peri-
sumed by the rethermalizer while reheating bags of refrigerated
ods.
clam chowder.
5.5 Production capacity is used by food service operators to
3.1.13 test method, n—a definitive procedure for the
choose a water-bath rethermalizer that matches their particular
identification, measurement, and evaluation of one or more
food output requirements.
qualities, characteristics, or properties of a material, product,
5.6 Retherm-energy efficiency is a precise indicator of the
system, or service that produces a test results.
water bath rethermalizer’s energy performance under full-load
3.1.14 uncertainty, n—measure of systematic and precision
condition. This information enables the operator to consider
errors in specified instrumentation or measure of repeatability
energy performance when selecting a water-bath rethermalizer.
of a reported test result.
3.1.15 water-bath rethermalizer, n—appliance, including a
6. Apparatus
rethermalizing vessel, in which water is placed to such a depth
6.1 Analytical Balance Scale, for measuring weights up to
that the food is essentially supported by displacement of the
15 lb (6.8 kg), with a resolution of 0.01 lb (0.004 kg) and an
water rather than by the bottom of the vessel, which is designed
uncertainty of 0.01 lb (0.004 kg).
for the purpose of reheating pre-cooked food contained in
vacuum-sealed, boilable bags.
6.2 Barometer, for measuring absolute atmospheric
pressure, to be used for adjustment of measured gas volume to
4. Summary of Test Method
standard conditions. Shall have a resolution of 0.2 in. Hg (670
Pa) and an uncertainty of 0.2 in. Hg (670 Pa).
4.1 The water-bath rethermalizer under test is connected to
the appropriate metered energy source. The measured energy
6.3 Canopy Exhaust Hood, 4 ft (1.2 m) in depth, wall-
input rate is determined and checked against the rated input
mounted with the lower edge of the hood 6 ft, 6 in. (1.98 m)
before continuing with testing.
from the floor and with the capacity to operate at a nominal net
exhaust ventilation rate of 300 cfm per linear foot (460L/s per
4.2 The water temperature in the rethermalizing zone of the
linear metre) of active hood length. This hood shall extend a
water-bath rethermalizer is monitored at a location chosen to
minimum of 6 in. (152 mm) past both sides and the front of the
represent the average temperature of the water while the
rethermalizing appliance and shall not incorporate side curtains
water-bath rethermalizer maintains a specified rethermalizing
or partitions. Makeup air shall be delivered through face
temperature.
registers or from the space, or both.
4.3 Preheat energy, time, and rate are determined while the
6.4 Data Acquisition System, for measuring energy and
water-bath rethermalizer is operated with the thermostat(s) set
temperatures, capable of multiple temperature displays updat-
to specified temperature.
ing at least every 2 s.
4.4 The idle energy is determined while the water-bath
rethermalizer is operated in a ready-to-use state with the 6.5 Flow Meter, for measuring total water consumption of
thermostat(s) set to the calibrated temperature. The rate of pilot the appliance. Shall have a resolution of 0.01 gal (0.04 L) and
energy consumption also is determined when applicable to the an uncertainty of 0.01 gal (0.04 L) at a flow rate as low as 0.2
water-bath rethermalizer under test. gpm (0.8 lpm).
F2473 − 12 (2023)
6.6 Gas Meter, for measuring the gas consumption of a 6 in. (1.98 m) from the floor. Position the water-bath rether-
water-bath rethermalizer, shall be a positive displacement type malizer with the front edge of the water in the rethermalizing
3 3
with a resolution of at least 0.01 ft (0.0003 m ) and a vat inset 6 in. (152 mm) from the front edge of the hood at the
maximum uncertainty no greater than 1 % of the measured manufacturer’s recommended working height. The length of
3 3
value for any demand greater than 2.2 ft (0.06 m ) per hour. If the exhaust hood and active filter area shall extend a minimum
the meter is used for measuring the gas consumed by the pilot of 6 in. (152 mm) past the vertical plane of both sides of the
3 3
lights, it shall have a resolution of at least 0.01 ft (0.0003 m ) water-bath rethermalizer. In addition, both sides of the water-
and a maximum uncertainty no greater than 2 % of the bath rethermalizer shall be a minimum of 3 ft (0.9 m) from any
measured value. sidewall, side partition, or other operating appliance. The
exhaust ventilation rate shall be 300 cfm per linear foot (460
6.7 Pressure Gage, for monitoring gas pressure. Shall have
L/s per linear metre) of hood length. The associated heating or
a range of 0 to 15 in. H O (0 to 3.7 kPa), a resolution of 0.5 in.
cooling system shall be capable of maintaining an ambient
H O (125 kPa), and a maximum uncertainty of 1 % of the
temperature of 73 6 3°F (22 6 2°C) within the testing
measured value.
environment when the exhaust ventilation system is operating.
6.8 Stop Watch, with a 1-s resolution.
9.3 The testing environment during energy tests shall be
6.9 Thermocouple Probe(s), industry standard type T or
maintained in accordance with the section on performance for
type K thermocouples capable of immersion, with a range of
open top hot food holding equipment room specifications of
from 50 to 400°F (10 to 204°C) and an uncertainty of 61°F
NSF/ANSI 4. NSF/ANSI 4 test room conditions are ambient
(60.5°C).
temperature of 73 6 3°F (22 6 2°C), no vertical temperature
6.10 Temperature Sensor, for measuring natural gas tem- gradient exceeding 1.5°F/ft (2.5°C/m), and maximum air
perature in the range of 50 to 100°F (10 to 38°C) with an
current velocity of 50 ft/min (0.25 m/s).
uncertainty of 61°F (60.5°C).
9.4 Connect the water-bath rethermalizer to a calibrated
6.11 Watt-Hour Meter, for measuring the electrical energy
energy test meter. For gas installations, install a pressure
consumption of a water-bath rethermalizer, shall have a reso-
regulator downstream from the meter to maintain a constant
lution of at least 10 Wh and a maximum uncertainty no greater
pressure of gas for all tests. Install instrumentation to record
than 1.5 % of the measured value for any demand greater than
both the pressure and temperature of the gas supplied to the
100 W. For any demand less than 100 W, the meter shall have
water-bath rethermalizer and the barometric pressure during
a resolution of at least 10 Wh and a maximum uncertainty no
each test so that the measured gas flow can be corrected to
greater than 10 %.
standard conditions. For electric installations, a voltage regu-
lator may be required during tests if the voltage supply is not
7. Reagents and Materials
within 62.5 % of the manufacturer’s “nameplate” voltage.
7.1 Water used shall have a maximum hardness of three
9.5 For an electric water-bath rethermalizer, confirm (while
grains per gallon. Distilled water may be used.
the water-bath rethermalizer elements are energized) that the
supply voltage is within 62.5 % of the operating voltage
7.2 New England Clam Chowder Soup, refrigerated, ready
specified by the manufacturer. Record the test voltage for each
to use, in nominal 1-gal (3.8-L) vacuum packed bags or
test.
“chubs,” weighing 6.0 6 0.2 lb (2.72 6 0.09 kg) per bag. The
NOTE 2—It is the intent of the testing procedure in this test method to
clam chowder shall be stabilized in a refrigerator at 38 6 2°F
evaluate the performance of a water-bath rethermalizer at its rated electric
(3 6 1°C).
voltage. If the unit is rated dual voltage (that is, designed to operate at
NOTE 1—Generic brand New England Clam Chowder has been proven
either 240 or 480 V with no change in components), the voltage selected
to be an acceptable product for testing by the Food Service Technology
by the manufacturer or tester, or both, shall be reported. If a water-bath
Center.
rethermalizer is designed to operate at two voltages without a change in
the resistance of the heating elements, the performance of the unit (for
8. Sampling and Test Units
example, preheat time) may differ at the two voltages.
8.1 Water-Bath Rethermalizer—Select a representative pro-
9.6 For a gas water-bath rethermalizer, adjust (during maxi-
duction model for performance testing.
mum energy input) the gas supply pressure downstream from
the appliance’s pressure regulator to within 62.5 % of the
9. Preparation of Apparatus
operating manifold pressure specified by the manufacturer.
Make adjustments to the water-bath rethermalizer following
9.1 Measure the water-bath rethermalizer’s vat’s rethermal-
the manufacturer’s recommendations for optimizing combus-
izing capacity. The water-bath rethermalizer’s rethermalizing
tion. Proper combustion may be verified by measuring air-free
vat may be shaped in such a way that simple measurements do
CO in accordance with ANSI Z83.11.
not yield the true rethermalizing capacity. In this case, fill the
water-bath rethermalizer with water till the bottom edge of the
9.7 Make the water-bath rethermalizer ready for use in
rethermalizing capacity is reached. Then, measure the volume
accordance with the manufacturer’s instructions. Clean the
of water required to fill the rethermalizing capacity to the top.
water-bath rethermalizer’s vat by “boiling” with the manufac-
9.2 Install the appliance according to the manufacturer’s turer’s recommended cleaner and water and then rinsing the
instructions under a 4-ft (1.2-m) deep canopy exhaust hood inside of the rethermalizing-vat thoroughly before starting each
mounted against the wall, with the lower edge of the hood 6 ft, test procedure.
F2473 − 12 (2023)
9.8 To prepare the water-bath rethermalizer for temperature 10.1.1.4 Measured gas pressure,
calibration, attach an immersion type thermocouple in the
10.1.1.5 Barometric pressure, and
rethermalizing vat before beginning any test. The thermo-
10.1.1.6 Energy input rate during or immediately prior to
couple used to calibrate the water-bath rethermalizer shall be
test.
located in the back of the rethermalizing vat, about ⁄2 in. (13
1 NOTE 3—The preferred method for determining the heating value of the
mm) from the back edge of the rethermalizing vat, ⁄2 in. (13
supplied to the water-bath rethermalizer under test is by using a calorim-
mm) above the heat transfer area or elements, or both, and
eter of gas chromatograph in accordance with accepted laboratory
located in the centered in relation to the sides of the rether-
procedures. The use of “bottled” natural gas with a certified heating value
3 3
malizing vat.
within the specified 1025 6 25 Btu/ft (38 160 6 930 kJ/m ) range is an
acceptable alternative.
9.9 Fresh water supply to water-bath rethermalizer should
10.1.2 For gas water-bath rethermalizers, add electric en-
be monitored to ensure that water temperature is 65 6 5°F (18
ergy consumption to gas energy for all tests, with the exception
6 3°C).
of the energy input rate test (10.2).
9.10 Install flow meter to the water-bath rethermalizer water
10.1.3 For electric water-bath rethermalizers, record the
inlet such that total water flow to the appliance is measured.
following for each run of each test run:
9.11 Food Racks, for holding food packages upright during
10.1.3.1 Voltage while elements are energized, and
the test shall be used. If the manufacturer does not have food
10.1.3.2 Energy input rate during or immediately prior to
racks specifically designed for the water bath rethermalizer,
test run.
then stainless steel wire racks conforming to the specifications
10.1.4 For each test run, confirm that the peak input rate is
in Fig. 1 may be used. Food racks must have clamps that will
within 65 % of the rated nameplate input. If the difference is
securely fasten the food and also have pins that will pierce food
greater than 5 %, terminate testing and contact the manufac-
bags keeping them from floating.
turer. The manufacturer may make appropriate changes or
9.12 Use the cooking racks to determine the maximum
adjustments to the water-bath rethermalizer.
number of 6-lb clam chowder chubs to be placed inside each
10.1.5 For all tests, record the altitude of the testing facility.
vat. Use one chub per rack and place it vertically inside the vat
10.1.6 For all tests, maintain water level at the indication
and place as many racks as possible until the vat is full. Record
line. If the water-bath rethermalizer has no indication line, then
this value and use this amount for testing.
maintain water level to the manufacturer’s recommended
capacity at all times.
10. Procedure
10.2 Measured Energy Input Rate:
10.1 General:
10.2.1 Load the water-bath rethermalizer to the indicated fill
10.1.1 For gas appliances, record the following for each test
line with fresh water and turn the water-bath rethermalizer on
run:
with the temperature control(s) set to the maximum setting.
10.1.1.1 Higher heating value,
10.1.1.2 Standard gas pressure and temperature used to 10.2.2 Let the water-bath rethermalizer run for a period of
correct measured gas volume to standard conditions, 15 min, then monitor the time required for the water-bath
3 3
10.1.1.3 Measured gas temperature, rethermalizer to consume 5 ft (0.14 m ) of gas. Adjustments to
FIG. 1 Food Racks in Rethermalizer Used for Efficiency Tests
F2473 − 12 (2023)
the appliance’s input rate may be made by adjusting gas 10.4.2 Turn the water-bath rethermalizer on with the tem-
manifold pressure (gas water-bath rethermalizer). perature controls set to attain the rethermalizing temperature
calibrated in 10.3.
10.2.3 For electric water-bath rethermalizers, monitor the
energy consumption for 15 min with the controls set to achieve
NOTE 7—It is the intent of this procedure to test the appliance at the
maximum input.
rethermalizing temperature calibrated in 10.3. If the appliance is unable to
10.2.4 In accordance with 11.4, calculate the measured
achieve the rethermalizing temperature, then the manufacturer needs to be
contacted. The manufacturer may make appropriate changes or adjust-
energy input rate for the water-bath rethermalizer under test.
ments to the water-bath rethermalizer.
Report and compare the measured input to the “nameplate”
energy input rate in Btu/h or kW. Confirm that the measured
10.4.3 Begin monitoring energy consumption and time as
input rate is within 65 % of rated “nameplate” energy input
soon as the water-bath rethermalizer is turned on. The preheat
rate. If the difference is greater than 65 %, testing shall be
period is measured from 75 to 195°F (24 to 91°C). Use the
terminated and the manufacturer contacted. The manufacturer
preheat energy consumption and time from 75 to 195°F (24 to
may make appropriate changes or adjustments to the water-
91°C) for preheat energy consumption and elapsed time.
bath rethermalizer. Also, the power supply may be changed, if
10.5 Idle Energy Rate:
necessary, to conform to manufacturer’s specifications. It is the
10.5.1 Ensure that the water-bath rethermalizer is filled to
intent of the testing procedures in this test method to evaluate
the indicated fill line or manufacturer’s recommended water
the performance of a water-bath rethermalizer at its rated
level. If the manufacturer provides a cover, then make sure that
energy input rate.
the cover is in place over the rethermalizer vat.
10.3 Calibration:
10.5.2 Allow the water-bath rethermalizer water to stabilize
at calibrated idle temperature for at least 30 min after the last
NOTE 4—The manufacturer may have a calibration procedure that may
give some insight into their thermostatic control strategy. The manufac-
thermostat has commenced cycling about the thermostat set
turer’s calibration procedure may be used initially to help in the calibra-
point.
tion of the rethermalizing temperature. After applying the manufacturer’s
10.5.3 Record the water-bath rethermalizer water
calibration procedure, confirm calibration with 10.3.
temperature, barometric pressure, and ambient temperature at
10.3.1 Fresh water temperature supplied to the water-bath
the start of the test.
rethermalizer shall be 65 6 5°F (18 6 3°C).
10.5.4 Proceed to monitor the elapsed time and the energy
NOTE 5—If the fresh water temperature is not within the specified consumption of the water-bath rethermalizer while it is oper-
temperature, mix the supply water with hot or cold sources to meet the
ated under this idle condition for a minimum of 2 h.
desired temperature. The supply water can be tempered to obtain the
10.6 Pilot Energy Rate (Gas Model with Standing Pilots):
proper supply water temperature.
10.6.1 Where applicable, set the gas valve controlling the
10.3.2 Ensure that the water-bath rethermalizer water is
gas supply to the appliance to the “pilot” position. Otherwise
loaded to the indicated fill line or manufacturer’s recom-
set the temperature controls to the “off” position.
mended water level. Preheat and allow the water-bath rether-
10.6.2 Light and adjust pilots according to manufacturer’s
malizer to stabilize for 30 min before beginning temperature
instructions.
calibration.
10.6.3 Record gas reading, gas temperature, gas pressure,
10.3.3 The water-bath rethermalizer water temperature shall
ambient temperature, barometric pressure, electric energy
be measured by attaching a calibrated immersion thermocouple
consumed, and time before and after a minimum of 8 h of pilot
type in the rear of the rethermalizing zone as detailed in 9.9.
operation.
Adjust the water-bath rethermalizer temperature control(s) to
maintain an average water vat temperature of 195 6 5°F (91 6
10.7 Rethermalization Time Determination:
3°C). Record the water temperature over a 1-h period to verify
10.7.1 Ensure that water-bath rethermalizer water is loaded
temperature of the water at 195 6 5°F (91 6 3°C). The water
to the indicated fill line. If there is no fill line, then fill to
temperature recorded over a 1-h period shall be considered as
manufacturer’s recommended water level.
the average temperature for the water-bath rethermalizer.
10.7.2 Preheat the rethermalizer and allow the unit to
10.4 Preheat-Energy Consumption, Time, and Rate:
stabilize for 30 min after being preheated.
10.4.1 Ensure that the water-bath rethermalizer is filled to
10.7.3 Ensure that water-bath rethermalizer water is loaded
the indicated fill line. If there is no indication line, then fill to
to the indicated water-bath rethermalizer fill line. If there is no
the manufacturer’s recommended water level. Record water
fill line, then fill to manufacturer’s recommended water level.
temperature, barometric pressure, and ambient kitchen tem-
Confirm that the water-bath rethermalizer-water temperature is
perature at the start of the test (water temperature shall be 65
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