Groen VRC-6E User Manual

Groen Vortex, Model VRC-6E

Electric Steamer Performance Test

Application of ASTM Standard

Test Method F 1484-99

FSTC Report # 5011.03.23

Food Service Technology Center

May 2003

Prepared by:

Victor Kong

David Zabrowski

Fisher-Nickel, Inc.

Contributors:

Angelo Karas

Fisher-Nickel, Inc.

© 2003 by Fisher-Nickel, inc. All rights reserved.

The information in this report is based on data generated at the Food Service Technology Center.

Acknowledgments

California consumers are not obligated to purchase any full service
or other service not funded by this program. This program is funded
by California utility ratepayers under the auspices of the California
Public Utilities Commission.

Los consumidores en California no estan obligados a comprar servicios completos o
adicionales que no esten cubiertos bajo este programa. Este programa esta financiado
por los usuarios de servicios públicos en California bajo la jurisdiccion de la Comision
de Servicios Públicos de California.

A National Advisory Group provides guidance to the Food Service
Technology Center Project. Members include:

Advantica Restaurant Group
Applebee’s International Group
California Energy Commission (CEC)
California Restaurant Association
Carl Karcher Enterprises, Inc.
DJ Horton & Associates
Electric Power Research Institute (EPRI)
Enbridge Gas Distribution
EPA Energy Star
Gas Technology Institute (GTI)
Lawrence Berkeley National Laboratories
McDonald’s Corporation
National Restaurant Association
Pacific Gas and Electric Company
Safeway, Inc.
Southern California Edison
Underwriters Laboratories (UL)
University of California at Berkeley
University of California at Riverside
US Department of Energy, FEMP

Policy on the Use of Food Service Technology Center

Test Results and Other Related Information

• Fisher-Nickel, inc. and the Food Service Technology Center

(FSTC) do not endorse particular products or services from any
specific manufacturer or service provider.

• The FSTC is strongly committed to testing food service equipment

using the best available scientific techniques and instrumentation.

• The FSTC is neutral as to fuel and energy source. It does not, in

any way, encourage or promote the use of any fuel or energy
source nor does it endorse any of the equipment tested at the
FSTC.

• FSTC test results are made available to the general public

through technical research reports and publications and are pro­tected under U.S. and international copyright laws.

• In the event that FSTC data are to be reported, quoted, or referred

to in any way in publications, papers, brochures, advertising, or
any other publicly available documents, the rules of copyright
must be strictly followed, including written permission from Fisher­Nickel, inc. in advance and proper attribution to Fisher-Nickel, inc.
and the Food Service Technology Center. In any such publication,
sufficient text must be excerpted or quoted so as to give full and
fair representation of findings as reported in the original
documentation from FSTC.

Legal Notice

This report was prepared as a result of work sponsored by the California
Public Utilities Commission (Commission). It does not necessarily represent
the views of the Commission, its employees, or the State of California. The
Commission, the State of California, its employees, contractors, and subcon­tractors make no warranty, express or implied, and assume no legal liability
for the information in this report; nor does any party represent that the use of
this information will not infringe upon privately owned rights. This report has
not been approved or disapproved by the Commission nor has the Commis­sion passed upon the accuracy or adequacy of the information in this report.

Specific appreciation is extended to Groen, Inc. for supplying the
FSTC with a Vortex, Model VRC-6E connectionless steamer for
controlled testing in the appliance laboratory.

Contents

Page

Executive Summary................................................................................ iii

1 Introduction ..................................................................................... 1-1

Background ................................................................................. 1-1

Objectives ................................................................................... 1-2

Appliance Description ................................................................. 1-2

2 Methods ........................................................................................... 2-1

Setup and Instrumentation .......................................................... 2-1

Non-Cooking Tests...................................................................... 2-2

Frozen Green Pea Efficiency Tests............................................. 2-2

Red Potato Efficiency Tests......................................................... 2-2

3 Results ............................................................................................. 3-1

Energy Input Rate........................................................................ 3-1

Preheat and Idle Tests................................................................. 3-1

Cooking Tests ............................................................................. 3-2

4 Conclusions...................................................................................... 4-1

5 References ....................................................................................... 5-1

Appendix A: Glossary
Appendix B: Appliance Specifications
Appendix C: Results Reporting Sheets
Appendix D: Cooking-Energy Efficiency Data

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Food Service Technology Center

List of Figures and Tables

Figures

Tables

Page

1-1 The Groen Vortex steamer.......................................................... 1-3

2-1 The Vortex instrumented and ready for testing............................ 2-1

2-2 Frozen green pea load................................................................. 2-2

2-3 Red potato load........................................................................... 2-3

3-1 Preheat characteristics................................................................ 3-1

3-2 Steamer part-load cooking-energy efficiency............................... 3-5

3-3 Steamer cooking-energy efficiency results .................................. 3-6

3-4 Steamer cooking energy consumption profile.............................. 3-7

Page

1-1 Appliance Specifications.............................................................. 1-3

3-1 Average Input, Preheat and Idle Test Results............................. 3-2

3-2 Frozen Green Pea Cooking Test Results.................................... 3-4

3-3 Red Potato Cooking Test Results................................................ 3-4

5011.03.23 ii
Food Service Technology Center

Executive Summary

The Food Service Technology Center (FSTC) tested the Groen Vortex, Model
VRC-6E connectionless electric steamer under the controlled conditions of the
American Society for Testing and Materials (ASTM) Standard Test Method
for the Performance of Steam Cookers.

1

Steamer performance was
characterized by preheat duration and energy consumption, idle energy rate,
cooking energy rate and efficiency, production capacity, water consumption,
and condensate temperature from product testing. Cooking tests were
conducted with frozen green peas and grade B red potatoes in accordance with
ASTM test materials specifications for weight, size, and water content.

1

Since
the Vortex was not configured with an automatic water fill option or
condensate drain, researchers did not monitor water consumption and
condensate temperature for these tests.

The Groen Vortex, Model VRC-6E is one of the best electric connectionless
steamers tested to date at the FSTC. The Vortex performed outstandingly
compared with other connectionless steamers thanks to its unprecedented
heavy load (6 pan) cooking-energy efficiencies for frozen green peas (91.5%)
and red potatoes (71.0%). The Vortex also earns high marks for impressive
heavy load production capacities of 94.5 lb/h for frozen green peas and

116.2 lb/h for red potatoes.
Cooking-energy efficiency is a measure of how much of the energy that an

appliance consumes is actually delivered to the food product during the
cooking process. Cooking-energy efficiency is therefore defined by the
following relationship:

1

American Society for Testing and Materials, 1999. Standard Test Method for the Perform­ance of Steam Cookers. ASTM Designation F1484-99, in the Annual Book of ASTM Stan­dards, West Conshohocken, PA.

5011.03.23 iii
Food Service Technology Center

Executive Summary

EfficiencyEnergy -Cooking =

Food toEnergy

SteamertoEnergy

A summary of the ASTM test results is presented in Table ES-1.

Table ES-1. Summary of Vortex Steamer Performance.

Rated Energy Input Rate (kW) 12.0
Measured Energy Input Rate (kW) 12.6
Preheat Time (min) 17.0
Preheat Energy (kWh) 2.2
Idle Energy Rate (kW) 0.2

Frozen Green Peas

Light-Load Cooking-Energy Efficiency (%) 60.8 ± 2.1
Heavy-Load Cooking-Energy Efficiency (%) 91.5 ± 2.5
Production Capacity (lb/h) 94.5 ± 1.6

Red Potatoes

Light-Load Cooking-Energy Efficiency (%) 30.4 ± 2.5
Heavy-Load Cooking-Energy Efficiency (%) 71.0 ± 2.6
Production Capacity (lb/h) 116.2 ± 2.7

Beyond its respectable productivity and high cooking-energy efficiencies, the
Vortex steamer also exhibited low water usage. Typical water consumption
during heavy-load cooking tests was much lower than the unit’s 4.0-gallon
reservoir capacity. Other steam cooking technologies, such as boiler-based or
steam generator-type steamers, typically consume between 20 and 60 gal/h
while cooking.

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Food Service Technology Center

1 Introduction

Background

Steaming provides a fast-cooking option for preparing large quantities of
food, while retaining vital nutrients in the cooked product. Steamers are
versatile appliances that can be used to prepare almost any food that does not
require a crust. Delicate vegetables, such as asparagus and broccoli, are
cooked without damage; frozen foods are defrosted and cooked in one step;
and hard-to-cook meats, such as beef ribs, can be par-cooked quickly with less
weight loss than oven roasting.

Dedicated to the advancement of the food service industry, the Food Service
Technology Center (FSTC) has focused on the development of standard test
methods for commercial food service equipment since 1987. The primary
component of the FSTC is a 10,000 square-foot appliance laboratory equipped
with energy monitoring and data acquisition hardware, 60 linear feet of
canopy exhaust hoods integrated with utility distribution systems, appliance
setup and storage areas, and a state-of-the-art demonstration and training
facility.

The test methods, approved and ratified by the American Society for Testing
and Materials (ASTM), allow benchmarking of equipment so that users can
make informed comparisons among available equipment choices. By
collaborating with the Electric Power Research Institute (EPRI) and the Gas
Technology Institute (GTI) through matching funding agreements, the test
methods have remained unbiased to fuel choice. End-use customers and
commercial appliance manufacturers consider the FSTC to be the national
leader in commercial food service equipment testing and standards, sparking
alliances with several major chain customers to date.

Since the development of the ASTM test method for steam cookers in 1993,
the FSTC has tested a wide range of gas and electric steamers,

10

Groen's very own HyPerSteam 3 pan unit.

2–16

including

1

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Food Service Technology Center

Introduction

The Groen Vortex steamer is the product of continued dedication from Groen
to make quality connectionless steamers. The Vortex shares many of the same
features with its sibling, the HyPerSteam, including a powerful squirrel cage
fan that provides the advantages of forced convection steaming, a compart­ment with a mirror finish for easy cleaning and durability, and a deep four
gallon reservoir.

The glossary in Appendix A is provided so that the reader has a quick ref­erence to the terms used in this report.

Objectives

Appliance
Description

The objective of this report is to examine the operation and performance of
the Groen, Model VRC-6E steamer, under the controlled conditions of the
ASTM Standard Test Method. The scope of this testing is as follows:

1. Verify that the appliance is operating at the manufacturer’s rated
energy input.

2. Determine the time and energy required to preheat the steamer
to an operating condition.

3. Characterize the idle energy use of the steamer while maintain­ing a ready-to-cook state.

4. Determine the cooking-energy efficiency under four scenarios:
heavy-load frozen green peas (6 pans), light-load frozen green
peas (single-pan), heavy-load red potatoes (6 pans) and light­load red potatoes (single-pan).

5. Determine the production capacity, cooking energy rate and
cook time for each loading scenario.

The Groen Vortex, Model VRC-6E is a 6-pan capacity, single compartment,
electric, connectionless steamer (Figure 1-1). The steamer is powered by a

12.0-kW heating element placed beneath the cooking compartment’s water
reservoir. Steam is generated within the cooking compartment without a
separate boiler. Water is added and drained manually at the beginning and end
of the day. The cooking chamber accommodates six standard full-size, 2½-

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Introduction

inch deep hotel pans. The Vortex has two cooking modes: timed and
continuous. The timed mode allows operators to set a pre-determined
cooktime of up to 90 minutes. When the cook time has expired, the unit
automatically switches to a hold mode. This hold feature allows the operator
to maintain an idle state of 180°F inside the cooking compartment. In the
continuous cooking mode, steam generation is cycled automatically by
microprocessor controls or by manually shutting the unit on or off.

Appliance specifications are listed in Table 1-1, and the manufacturer’s
literature is in Appendix B. The appliance is pictured in Figure 1-1.

Table 1-1. Appliance Specifications.

Figure 1-1.
The Groen Vortex
steamer.

Manufacturer Groen, Inc.
Model Model VRC-6E Vortex
Generic Appliance

Type
Rated Input 12.0 kW
Technology Connectionless steamer with forced-convection.
Construction Mirror finished stainless-steel walls.
Interior 16 Ga. stainless-steel, mirror finish
Exterior 18 Ga. stainless-steel
Controls Main ON/OFF buttons. 90 minute mechanical timer with continuous

Compartment Capacity 6 (12" x 20" x 2

Dimensions

Connectionless, 1-compartment, electric, atmospheric, connec­tionless steamer.

steam or hold setting. Hold temperature is factory adjustable from
150°F to 190°F.

1

/2") pans, 4 (12" x 20" x 4") pans, or

3 (12" x 20" x 6") pans

1

23" x 23

/4" x 30"(w×d×h)

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2 Methods

Setup and
Instrumentation

The steamer was installed in accordance with the manufacturer’s instructions
and in accordance with Section 9 of the ASTM test method
deep canopy hood, with the lower edge of the hood 6 feet, 6 inches above the
floor and a minimum of 6 inches inside the vertical front edge of the hood.
The exhaust ventilation operated at a nominal rate of 150 cfm per linear foot
of hood with the ambient temperature maintained at 75

Power and energy were measured with a watt/watt-hour transducer that
generated an analog signal for instantaneous power and a pulse for every
10 Wh. The transducer and thermocouples were connected to a computerized

1

: under a 4-foot-

±5°F.

Figure 2-1.
The Vortex instrumented
for testing.

data acquisition unit that recorded data every 5 seconds. A voltage regulator,
connected to the steamer, maintained a steady voltage for all tests. Figure
2-1 shows the Vortex instrumented with the data acquisition system.

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Methods

Non-Cooking Tests

Frozen Green Pea
Efficiency Tests

The energy input rate was determined by measuring the energy consumed by
the steamer during a complete preheat cycle. The maximum power draw
during this period was reported as the measured energy input rate. Preheat
tests recorded the time and energy required for the steamer to reach operating
temperature from a cold start when turned on for the first time in a day. An
hour after the preheat cycle, idle energy consumption was monitored over a 2­hour period and conducted in the steamer's “idle/hold” mode.

Individually flash-frozen, grade A green peas (Figure 2-2) represented one of
two food products for steamer performance testing. Standard full-size (12" x
20" x 2½"), perforated stainless-steel hotel pans were used for cooking the
green peas. The Vortex required 6 pans of green peas for a full load, while a
single pan placed on the center rack of the steamer cavity comprised a light
load. Each pan contained 8.0
in perforated pans were stored in sealed plastic bags at 0
hours prior to testing. The pans of peas were transferred into an insulated box

± 0.2 lb of green peas. Pre-weighed green peas

± 5°F for at least 24

and transported to the testing location where the plastic bags were removed,
and the pan(s) of green peas were loaded into the steamer according to the
loading time prescribed in section 10.7.6 of the ASTM test method.

Since probing proves to be difficult and erroneous in measuring the
temperature of small-sized green peas, a water-bath calorimeter was utilized to
determine the final bulk temperature of the cooked green peas. The time

Figure 2-2.
Frozen green pea load.

Red Potato
Efficiency Tests

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Food Service Technology Center

required to cook the frozen peas to a bulk temperature of 180 ± 2°F was
determined through an iterative process. Once the cook time was established,
the test was replicated a minimum of three times to minimize the uncertainty
in the test results.

Freshly packed, size B, red potatoes (Figure 2-3) served as the second food
product for steamer performance testing. Again, the Vortex required 6 pans of

1

Methods

red potatoes for a full load and a single pan for a light load. Each pan

Figure 2-3.
Red potato load.

contained 8.0

± 0.2 pounds of red potatoes.

The red potatoes were loaded into perforated pans prior to the test and
stabilized to a room temperature of 75
to 195

± 2°F using a predetermined cook time. The final temperature was

± 5°F. The potatoes were then cooked

determined by probing a minimum of 3 potatoes during testing and then
randomly probing potatoes (using a hand-held, digital thermocouple meter)
within 3 minutes after cooking was terminated. Again, the test was replicated
a minimum of three times to minimize the uncertainty in the test results.

The ASTM results reporting sheets appear in Appendix C.

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3 Results

Energy Input Rate

Researchers compared the manufacturer's nameplate value for energy input
rate with that measured in the lab prior to any testing to ensure that the
steamer was operating within its specified parameters. The Vortex drew a
maximum energy input rate of 12.6 kW.

Preheat and Idle
Tests

Preheat Energy and Time

The cavity was manually filled with four gallons of water at 70
steamer was started in its “On” mode of operation indicated by continual
steaming cycles until the compartment reached approximately 203°F. Preheat
was complete when the primary elements had cycled off and the compartment
reached 203°F, indicating a ready-to-cook state. Figure 3-1 illustrates the
preheat and idle characteristics of the Vortex.

250

200

150

100

± 5°F. The

50

Compartment Temperature (°F) .

0

Figure 3-1.

Preheat characteristics.

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Food Service Technology Center

0 5 10 15 20 25 30

Test Time (min)

Results

Idle Energy Rate

Following the preheat period, the steamer was left in the “On” mode and
allowed to stabilize for one hour. Then, the steamer was placed in its
“idle/hold” mode and the energy consumption was monitored over a 2-hour
period and the idle energy rate was determined to be 0.2 kW.

Test Results

Rated energy input, preheat energy and idle rate test results are summarized in
Table 3-1. The Vortex had a preheat time of 17.0 minutes and exhibited a idle
rate of 0.2 kW.

Table 3-1. Average Input, Preheat and Idle Test Results.

Rated Energy Input Rate (kW) 12.0

Cooking Tests

Measured Energy Input Rate (kW) 12.6
Preheat to Operational Capacity:

Time (min) 17.0
Energy (kWh) 2.2

Idle Energy Rate (kW) 0.2

The steamer was tested using two different food products (green peas and red
potatoes) under two loading scenarios—heavy (6 pans) and light (single pan).
All cooking scenarios were conducted in the unit’s “On” mode.

The Groen Vortex steamer does not employ a separate boiler, water
connection or drain. Four gallons of water were poured into the reservior at
the bottom of the cooking compartment before testing began. The steamer was
emptied at the end of the day, as directed by the manufacturer’s instructions.

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Results

Typical water usage for each cooking scenario was less than the 4.0-gallon
capacity of the reservoir.

Frozen Green Pea Tests

Moisture content of the frozen green peas was 81% by weight, corresponding
to specific heats (Cp) of 0.44 Btu/lb°F for frozen and 0.84 Btu/lb°F for
thawed peas.

1

The Vortex required 30.5 minutes to cook a full load of frozen
green peas and had a cooking-energy efficiency of 91.5% and a production
capacity of 94.5 lb/h.

The light-load test required an average of 8.1 minutes when cooking a single
pan of frozen green peas. Cooking-energy efficiency and productivity during
the light-load tests were determined to be 60.8% and 59.4 lb/h, respectively.

Red Potato Tests

The red potatoes contained 84% moisture by weight with the specific heat
(Cp) of 0.87 Btu/lb°F.
a bulk cooked temperature of 195

1

A full load of potatoes averaged 24.8 minutes to reach

± 2°F. The cooking-energy efficiency and

production capacity was 71.0% and 116.2 lb/h, respectively.
The single pan of red potatoes required 18.0 minutes to achieve an average

bulk temperature of 195

± 2°F. The light-load potato test exhibited a cooking-

energy efficiency of 30.4% and a productivity of 26.7 lb/h.

Results Discussion

The rate at which steam condenses on food depends on the surface
temperature and area of the food. Therefore, frozen green peas (at 0°F) and
red potatoes (at room temperature) represent two extremities in steam
cooking. Frozen green peas, having a large surface area to volume ratio,
promote condensation. The energy transfer from steam to frozen food is high,
resulting in greater cooking-energy efficiency and productivity. Potatoes are

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Results

“tough” to cook, due to low surface to volume ratio and the slower rate of
condensation.

Appendix D lists the physical properties of the test food product and measured
values of each test run. Using the detailed equations provided in section 11 of
the Steamer ASTM Standard Test Method, the cooking-energy efficiencies are
calculated. Tables 3-2 and 3-3 summarize the Vortex’s cooking performance.

Table 3-2. Frozen Green Pea Cooking Test Results.

Heavy-Load Light-Load

Number of Pans 6 1
Cook Time (min) 30.5 8.1
Cooking Energy Rate (kW) 8.0 7.4
Cooking-Energy Efficiency (%) 91.5 60.8
Production Rate (lb/h) 94.5 59.4
Energy Consumption (Btu/lb) 292 435

Table 3-3. Red Potato Cooking Test Results.

Heavy-Load Light-Load

Number of Pans 6 1
Cook Time (min) 24.8 18.0
Cooking Energy Rate (kW) 5.1 2.8
Cooking-Energy Efficiency (%) 71.0 30.4
Production Rate (lb/h) 116.2 26.7
Energy Consumption (Btu/lb) 151 354

Figure 3-2 illustrates the relationship between cooking-energy efficiency and
production rate for this steamer, when cooking two different types of food

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Results

product. The upper line represents the part-load efficiency curve for the
steamer when cooking frozen vegetables, while the lower curve represents the
steamer’s part-load efficiency when cooking more stubborn food products.
Steamer production rate is a function of the cook time. Appendix D contains a
synopsis of test data for each replicate of the cooking tests.

Frozen Green Peas Red Potatoes

100

90
80
70
60
50
40

Light-Load

Heavy-Load

Figure 3-2.
Steamer part-load cook­ing-energy efficiency.

30
20

Cooking Energy Efficiency (%)

10

0

0 20 40 60 80 100 120 140

Production Rate (lb/h)

Note: Light-load = single pan/load; Heavy-load = 6 pans/load.

Figure 3-3 illustrates the relationship between the Vortex steamer’s average
cooking-energy efficiency and the production rate for different types of food
product at different test scenarios. Heavy loads tend to exhibit higher
efficiencies due to better use of the available compartment space, as opposed
to light load single pan tests, where most of the space in the steamer
compartment is empty. Furthermore, Figure 3-3 shows that the frozen green

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Results

peas have higher cooking-energy efficiencies than the red potatoes due to their
higher surface to volume ratio.

Figure 3-3.
Steamer cooking-energy
efficiency results.

100

91.5%

90
80
70

60.8%

60
50
40
30
20

Cooking Energy Efficiency (%)

10

0

Heavy-Load Peas Light-Load Peas Heavy-Load

Po ta toe s

Note: Light-load = single pan/load; Heavy-load = 6 pans/load.

71.0%

30.4%

Light-Load Potatoes

Figure 3-4 represents the cooking energy input rate for two different food
products at the two test load scenarios. The upper line represents the steamer’s
energy consumption rate when cooking frozen vegetables, while the lower
curve represents the steamer’s energy consumption rate when cooking more
stubborn food products. This graph can be used as a tool to estimate the daily
energy consumption and probable demand for the steamer in a real-world
operation, based on the type of usage. Average energy consumption rates at

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Results

15, 30, and 60 pounds per hour of frozen vegetables are 1.9 kW, 3.0 kW, and

4.1 kW, respectively. For an operation cooking an average of 15 pounds of
frozen vegetables per hour over the course of the day (e.g., 150 pounds of
food over a ten hour day), the probable demand contribution from this steamer
would be 1.9 kW.

Frozen Green Peas Red Potatoes

12

10

8

Figure 3-4.
Steamer cooking energy
consumption profile.

6

4

Cooking Energy Rate (kW)

2

0

0 20 40 60 80 100 120 140

Light-Load

Production Rate (lb/h)

Note: Light-load = single pan/load; Heavy-load = 6 pans/load.

Heavy-Load

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4 Conclusions

The Groen Vortex VRC-6E is a highly productive and energy efficient
connectionless, electric steamer. With its six-pan loading capacity, the unit
achieved one of the highest frozen green pea production capacities of any
connectionless steamer (94.5 lb/h). Its 116 pounds-per-hour red potato
production capacity was also one of the highest of any connectionless steamer
tested to date at the FSTC.
Vortex was able to transfer its steam energy to the food product quite
efficiently while minimizing heat loss. The Vortex was recorded as having the
highest heavy load frozen green pea cooking efficiencies (91.5%) and one of
the best efficiencies with red potatoes (71.0%) of any electric connectionless

3–10, 15, 16

During heavy load cooking tests, the

steamer.
While cooking tests revealed the steamer's ability to perform with minimal

energy input and short cook times, the Vortex was equally impressive with it's
very low 0.2 kW idle rate. This is a credit to the design of the steamer, both in
its ability to minimize heat loss and it's control strategy that allows it to
maintain a steady, standby temperature within the cooking compartment.

The Vortex steamer was subjected to a series of heavy and light load cooking
scenarios, and the steamer consumed less than 2.5 gallons during each
cooking test. On average, researchers needed only to replenish the water
reservoir with one to two gallons of water after multiple cooking tests. Steam­generator and boiler-based units typically consume between 20 and 60 gal/h
while cooking.

The Groen Vortex VRC-6E is an energy efficient connectionless steamer that
is versatile enough to satisfy all menu demands. Throughout all of the
rigorous ASTM tests, the Vortex outperformed nearly all other FSTC tested
steamers in its category. In addition, the Vortex also provides labor saving

2, 11–14

features such as a low maintenance mirror finish on the interior, a deep, four-

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Conclusions

inch reservoir, and an available, automatic water fill option. The Groen
Vortex is a perfect candidate for facilities looking to reduce operating and
maintenance costs. With its low energy consumption, high production rates,
and minimal water usage, it is a fine choice for replacing boiler-based
steamers and other connectionless steamers. Operators are sure to be pleased
with this quality steamer unit.

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5 References

1. American Society for Testing and Materials, 1999. Standard Test

Method for the Performance of Steam Cookers. ASTM Designation F

1484–99. In annual book of ASTM Standards, West Conshohocken, PA.

2. Selden, M., 1995. Development and Validation of a Uniform Testing

Procedure for Steam Cookers. Food Service Technology Center Report

1022.95.19, April.

3. Bell, T., Yap, D., 1999. Southbend Simple Steam, Model EZ-3 Electric

Steamer Performance Test: Application of ASTM Test Method F 1484-

99. Food Service Technology Center Report 5011.99.83, December.

4. Bell, T., Miner, S., Nickel, J., Zabrowski, D., 2001. Stellar Steam

CAPELLA Electric Steamer Performance Test: Application of ASTM
Test Method F 1484-99. Food Service Technology Report 5011.01.94,

January.

5. Bell, T., Miner, S., 2001. Vulcan VPX3 Electric Steamer Performance

Test: Application of ASTM Test Method F 1484-99. Food Service Tech­nology Center Report 5011.01.01, May.

6. Bell, T., Miner, S., 2001. Vulcan VPX5 Electric Steamer Performance

Test: Application of ASTM Test Method F 1484-99. Food Service Tech­nology Center Report 5011.01.02, May.

7. Bell, T., Nickel, J., 2001. Cleveland Range Inc., Electric Steamer Per-

formance Test: Application of ASTM Test Method F 1484-99. Food Ser­vice Technology Center Report 5011.00.84, November.

8. Bell, T., Miner, S., Nickel, J., Zabrowski, D., 2001. Market Forge, ET-

3E Electric Steamer Performance Test: Application of ASTM Test
Method F 1484-99. Food Service Technology Center Report

5011.01.99, April.

5011.03.23 5-1
Food Service Technology Center

References

9. Bell, T., Miner, S., Nickel, J., Zabrowski, D., 2001. Market Forge, ET-

5E Electric Steamer Performance Test: Application of ASTM Test
Method F 1484-99. Food Service Technology Center Report

5011.01.98, April.

10. Yap, D., Ardley, S., 1998. Groen HyperSteam, Model HY-3E Electric

Steamer Performance Test: Application of ASTM Standard Test Method
F1484-93. Food Service Technology Center Report 5011.98.54, May.

11. Bell, T., Nickel, J., 2001. Market Forge STP-6E Electric Steamer Per-

formance Test: Application of ASTM Test Method F 1484-99. Food Ser-

vice Technology Center Report 5011.01.05, December.

12. Bell, T., Nickel, J., 2001. Market Forge STP-6G Gas Steamer Perform-

ance Test: Application of ASTM Test Method F 1484-99. Food Service
Technology Center Report 5011.01.06, December.

13. Bell, T., Miner, S., Nickel, J., Zabrowski, D., 2000. Vulcan-Hart Gas

Steamer Performance Test, Model VL2GSS (Pressure) and Model
VS3616G (Atmospheric) Steamer Performance Test: Application of
ASTM Test Method F 1484-99. Food Service Technology Report

5011.00.85, December.

14. Bell, T., Miner, S., Nickel, J., Zabrowski, D., 2001. Vulcan-Hart Gas

Steamer Performance Test, Model VHX24G-3 Steamer Performance
Test: Application of ASTM Test Method F 1484-99. Food Service Tech-

nology Report 5011.01.97, January.

15. Yap, D., Ardley, S., 1998. AccuTemp Steam “n” Hold, Model 208-D6-

3.0 Electric Steamer Performance Test: Application of ASTM Test
Method F1484-99. Food Service Technology Center Report 5011.98.58,

May.

16. Yap, D., Bell, T., Knapp, S., 1999. AccuTemp Steam ‘n’ Hold, Model

208-D8-300 Electric Steamer Performance Test: Application of ASTM
Test Method F1484-99. Food Service Technology Center Report

5011.99.75, September.

5011.03.23 5-2
Food Service Technology Center

A Glossary

Boiler

Cooking-Energy Efficiency (%)

Self-contained electric, gas, or steam coil pow­ered vessel wherein water is boiled to produce
steam for the steam cooker. Also called a
steam generator.

Boiler Preheat
Preheat

Process of bringing the boiler water from po­table supply temperature to operating tempera­ture (pressure).

Condensate

A mixture of condensed steam and cooling
water, exiting the steam cooker and directed to
the floor drain.

Condensate Temperature (°F)

The temperature at which the condensate en­ters the floor drain.

Cooking Energy (kWh or kBtu)

The total energy consumed by an appliance as
it is used to cook a specified food product.

Cooking Energy Consumption Rate
(kW or kBtu/h)

The average rate of energy consumption dur­ing the cooking period.

The quantity of energy input to the food prod­ucts; expressed as a percentage of the quantity
of energy input to the appliance during the
heavy- and light-load tests.

Duty Cycle (%)
Load Factor

The average energy consumption rate (based
on a specified operating period for the appli­ance) expressed as a percentage of the meas­ured energy input rate.

Duty Cycle =

Energy Input Rate (kW or kBtu/h)
Energy Consumption Rate
Energy Rate

The peak rate at which an appliance will con­sume energy, typically reflected during pre­heat.

Frozen Green Peas Load

12 x 20 x 2½ in. hotel pan filled with 8.0 ± 0.2
lb of frozen, grade A, green peas subsequently
frozen to 0±5°F. One of two food products
used to determine cooking-energy efficiency
and production capacity.

High-Pressure Steam Cooker

Steam cooker wherein cooking compartment
operates between 10 and 15 psig (ASTM
F1217-92 Classification Type III).

Rate nConsumptioEnergy Average

RateInput Energy Measured

x 100

5011.03.23 A-1
Food Service Technology Center

Glossary

Heating Value (Btu/ft3)

Heating Content

The quantity of heat (energy) generated by the
combustion of fuel. For natural gas, this quan­tity varies depending on the constituents of the
gas.

Ice Load

12 x 20 x 2½ in. hotel pan filled with 8.0 ± 0.2
lb of water and subsequently frozen to 0±5°F.
This is used to simulate a food product load in
the ice load cooking-energy efficiency and
production capacity test.

Idle Energy Rate (kW or Btu/h)
Idle Energy Input Rate
Idle Rate

The rate of appliance energy consumption
while it is “holding” or maintaining a stabi­lized operating condition or temperature.

Idle Temperature (°F, Setting)

Measured Input Rate (kW or Btu/h)

Measured Energy Input Rate
Measured Peak Energy Input Rate

The maximum or peak rate at which an appli­ance consumes energy, typically reflected dur­ing appliance preheat (i.e., the period of opera­tion when all burners or elements are “on”).

Pilot Energy Rate (kBtu/h)
Pilot Energy Consumption Rate

The rate of energy consumption by the stand­ing or constant pilot while the appliance is not
being operated (i.e., when the thermostats or
control knobs have been turned off by the food
service operator).

Potato Load

12 x 20 x 2½ in. hotel pan filled with 8.0 ± 0.2
lb of fresh, whole, US No. 1, size B, red pota­toes. One of two food products used to deter­mine cooking-energy efficiency and produc­tion capacity.

The temperature of the cooking cavity/surface
(selected by the appliance operator or speci­fied for a controlled test) that is maintained by
the appliance under an idle condition.

Idle Duty Cycle (%)
Idle Energy Factor

The idle energy consumption rate expressed as
a percentage of the measured energy input
rate.

Idle Duty Cycle =

Rate nConsumptioEnergy Idle

x 100

RateInput Energy Measured

Preheat Energy (kWh or Btu)
Preheat Energy Consumption

The total amount of energy consumed by an
appliance during the preheat period.

Preheat Rate (°F/min)

The rate at which the cooking surface heats
during a preheat.

Preheat Time (minute)
Preheat Period

Low-Pressure Steam Cooker

Steam cooker wherein the cooking compart­ment operates between 3 and 9.9 psig (ASTM
F1217-92 Classification Type II).

5011.03.23 A-2
Food Service Technology Center

The time required for an appliance to heat
from the ambient room temperature (75 ± 5°F)
to a specified (and calibrated) operating tem­perature or thermostat set point.

Glossary

Production Capacity (lb/h)

The maximum production rate of an appliance
while cooking a specified food product in ac­cordance with the heavy-load cooking test.

Production Rate (lb/h)
Productivity

The average rate at which an appliance brings
a specified food product to a specified
“cooked” condition.

Rated Energy Input Rate
(kW, W or Btu/h, Btu/h)
Input Rating (ANSI definition)
Nameplate Energy Input Rate
Rated Input

The maximum or peak rate at which an appli­ance consumes energy as rated by the manu­facturer and specified on the nameplate.

Steam Cooker

Test Method

A definitive procedure for the identification,
measurement, and evaluation of one or more
qualities, characteristics, or properties of a
material, product, system, or service that pro­duces a test result.

Typical Day

A sampled day of average appliance usage
based on observations and/or operator inter­views, used to develop an energy cost model
for the appliance.

Water Consumption (gal/h)

Water consumed by the steam cooker. In­cludes both water used in the production of
steam and cooling water (if applicable) for
condensing/cooling unused steam.

Cooking appliance wherein heat is imparted to
food in a closed compartment by direct contact
with steam. The compartment can be at or
above atmospheric pressure. The steam can be
static or circulated.

5011.03.23 A-3
Food Service Technology Center

B Appliance Specifications

Appendix B includes the product literature for the Groen Vortex, Model
VRC-6E steamer.

5011.03.23 B-1
Food Service Technology Center

C Results Reporting Sheets

Manufacturer: Groen
Model: Vortex, VRC-6E
Date: May 2003

Test Steam Cooker

ASTM F 1216 Classification (check one for each classification)


______ Type II - Three to 9.9 psig compartment pressure
______ Type III - Ten to 15 psig compartment pressure



______ Size 2-6 - Two Compartment, 6 full-size pan capacity
______ Size 2-8 - Two Compartment, 8 full-size pan capacity
______ Size 2-10 - Two Compartment, 10 full-size pan capacity
______ Size 2-12 - Two Compartment, 12 full-size pan capacity
______ Size 2-16 - Two Compartment, 16 full-size pan capacity
______ Size 3-12 - Three Compartment, 12 full-size pan capacity
______ Size 3-15 - Three Compartment, 15 full-size pan capacity
______ Size 3-18 - Three Compartment, 18 full-size pan capacity
______ Size 3-24 - Three Compartment, 24 full-size pan capacity



______ Style C - Floor mounted on a cabinet base
______ Style D - Wall Mounted

______ Class A - Direct connection to potable external steam source
______ Class B - Self-contained steam coil steam generator
______ Class C - Self-contained gas fired steam generator



Type I - Zero to 2.9 psig compartment pressure

Size 1-3 - One Compartment, 3 full-size pan capacity
Size 1-4 - One Compartment, 4 full-size pan capacity
Size 1-5 - One Compartment, 5 full-size pan capacity
Size 1-6 - One Compartment, 6 full-size pan capacity

Style A - Counter mounted

Style B - Floor mounted on an open stand

Class D - Self-contained electric steam generator

5011.03.23 C-1
Food Service Technology Center

Results Reporting Sheets

Description of operational characteristics: Approximately 4 gallons of water is manually poured in the
bottom of the cooking compartment. Food is cooked with natural-convection steam to a desired temperature
and held until ready to be served.

Apparatus

The steamer was installed in accordance with the manufacturer’s instructions under a 4-foot-deep canopy
hood, with the lower edge of the hood 6 feet, 6 inches above the floor and a minimum of 6 inches inside the
vertical front edge of the hood. The exhaust ventilation operated at a nominal rate of 150 cfm per linear foot
of hood with the ambient temperature maintained between 75

1

accordance with Section 9 of the ASTM test method.

± 5°F. All test apparatus were installed in

The steamer was instrumented with an electric transducer to measure power and energy; a voltage regulator
was used to maintain constant voltage for all tests. A computerized data acquisition system recorded test
information at 10-seconds intervals for the red potato tests and 5-second intervals for the rest. All test
apparatus were installed in accordance with Section 9 of the ASTM test method.

Energy Input Rate

Test Voltage 208 V
Measured 12.6 kW
Rated 12.0 kW
Percent Difference between Measured and Rated 5.0%

Appliance Preheat Energy Consumption and Duration

Test Voltage 208 V
Energy Consumption 2.2 kWh
Duration 17.0 min

5011.03.23 C-2
Food Service Technology Center

Results Reporting Sheets

Appliance Idle Energy Rate

Test Voltage 208 V
Idle Energy Rate 0.2 kW

Frozen Green Peas
Consumption Rate

Heavy-Load:
Test Voltage 208 V

Cooking Time 30.5 min

Cooking Time, Energy Efficiency, Energy Rate, Production Capacity, and Water

Cooking-Energy Efficiency 91.5
Cooking Energy Rate 8.0
Production Capacity 94.5

Water Consumption Rate

±2.5%

± 0.1kW

±1.6 lb/h

< 4.0 gal/h

Light-Load:

Test Voltage 208 V
Cooking Time 8.1 min
Cooking-Energy Efficiency 60.8

Cooking Energy Rate 7.4
Production Rate 59.4

Water Consumption Rate

±2.1%

± 0.5 kW

± 0.0 lb/h

< 4.0 gal/h

5011.03.23 C-3
Food Service Technology Center

Results Reporting Sheets

Whole Red Potatoes Cooking Time, Energy Efficiency, Energy Rate, Production Capacity, and Water
Consumption Rate

Heavy-Load:
Test Voltage 208 V
Cooking Time 24.8 min
Cooking-Energy Efficiency 71.0

Cooking Energy Rate 5.1
Production Capacity 116.2

Water Consumption Rate

±2.7%

± 0.2 kW

± 2.7 lb/h

< 4.0 gal/h

Light-Load:

Test Voltage 208 V
Cooking Time 18.0 min
Cooking-Energy Efficiency 30.4

Cooking Energy Rate 2.8
Production Capacity 26.7

Water Consumption Rate

± 2.5%

± 0.1kW

± 0.9 lb/h

< 4.0 gal/h

5011.03.23 C-4
Food Service Technology Center

D Cooking-Energy Efficiency Data

Table D-1. Specific Heat and Latent Heat.

Specific Heat (Btu/lb, °F)

Water 1.00
Green Peas, Frozen 0.44
Green Peas, Cooked 0.84
Red Potatoes 0.84

Latent Heat (Btu/lb)

Fusion, Water 144
Vaporization, Water 970

5011.03.23 D-1
Food Service Technology Center

Cooking-Energy Efficiency Data

Table D-2. Heavy-Load Peas Data

Replication 1 Replication 2 Replication 3

Measured Values

Number of Pan(s) 6 6 6

Cook Time (min) 30.25 30.5 30.7

Initial Water Temperature (°F) 37.0 37.2 39.5
Final Water Temperature (°F) 95.4 95.8 97.7
Frozen Food Temperature (°F) 0.0 0.00 0.0
Weight of Empty Calorimeter (lb) 44.7 44.7 44.7
Weight of Full Calorimeter (lb) 155.2 155.2 155.7
Weight of Calorimeter Water (lb) 60.0 60.0 60.0
Weight of Cooked Food (lb) 50.5 50.5 51.0
Weight of Frozen Food (lb) 48.0 48.0 48.0
Weight of Stainless-Steel Pans (lb) 15.7 15.7 15.7
Moisture Content (%) 81 81 81
Condensate Temperature (°F) n/a n/a n/a
Water Consumption (gal/h) <4.0 <4.0 <4.0

Calculated Values

Moisture Weight in Green Peas (lb) 38.9 38.9 38.9
Final Food Temperature (°F) 178.0 178.6 179.2
Cooking Energy (kWh) 4.04 4.12 4.16
Energy Consumed by Green Peas (Btu) 12,468 12,495 12,581

Energy to Food (Btu/lb) 259.8 260.3 262.1

Energy Consumed by Pans (Btu) 306.5 307.6 308.6
Energy of Boiler Re-init (Btu) n/a n/a n/a
Energy Consumed by the Steamer (Btu) 13,785 14,058 14,195
Energy to Steamer (Btu/lb of food cooked) 287.2 292.9 295.7

Cooking Energy Rate (kW) 8.0 8.0 8.1
Productivity (lb/h) 95.2 94.4 93.9
Energy Efficiency (%) 92.7 91.1 90.8

5011.03.23 D-2
Food Service Technology Center

Cooking-Energy Efficiency Data

Table D-3. Light-Load Peas Data

Replication 1 Replication 2 Replication 3

Measured Values

Number of Pan(s) 1 1 1

Cook Time (min) 8.08 8.08 8.08

Initial Water Temperature (°F) 33.6 36.7 38.5
Final Water Temperature (°F) 94.6 95.0 95.0
Frozen Food Temperature (°F) 0.0 0.0 0.0
Weight of Empty Calorimeter (lb) 44.7 44.7 44.7
Weight of Full Calorimeter (lb) 63.1 62.8 62.8
Weight of Calorimeter Water (lb) 10.0 10.0 10.0
Weight of Cooked Food (lb) 8.4 8.1 8.1
Weight of Frozen Food (lb) 8.0 8.0 8.0
Weight of Stainless-Steel Pans (lb) 2.8 2.4 2.4
Moisture Content (%) 81 81 81
Condensate Temperature (°F) n/a n/a n/a
Water Consumption (gal/h) <4.0 <4.0 <4.0

Calculated Values

Moisture Weight in Green Peas (lb) 6.5 6.5 6.5
Final Food Temperature (°F) 181.4 180.6 178.1
Cooking Energy (kWh) 1.04 1.00 1.02
Energy Consumed by Green Peas (Btu) 2,096 2,057 2,040

Energy to Food (Btu/lb) 262.0 257.1 255.0

Energy Consumed by Pans (Btu) 55.6 47.7 47.1
Energy of Boiler Re-init (Btu) n/a n/a n/a
Energy Consumed by the Steamer (Btu) 3,549 3,412 3,480
Energy to Steamer (Btu/lb of food cooked) 443.6 426.5 435.0

Cooking Energy Rate (kW) 7.4 7.3 7.7
Productivity (lb/h) 59.4 59.4 59.4
Energy Efficiency (%) 60.0 61.7 60.6

5011.03.23 D-3
Food Service Technology Center

Cooking-Energy Efficiency Data

Table D-4. Heavy-Load Potatoes Data

Replication 1 Replication 2 Replication 3

Measured Values

Number of Pan(s) 6 6 6

Cook Time (min) 25.08 24.67 24.69

Temperature of Uncooked Potatoes (°F) 73.8 71.6 73.1
Temperature of Cooked Potatoes (°F) 195.0 195.1 195.0
Weight of Stainless-Steel Pans (lb) 15.65 15.82 15.82
Weight of Potatoes (lb) 48.04 48.02 48.05
Total Potato Count 300 298 300
Moisture Content (%) 84 84 84
Condensate Temperature (°F) n/a n/a n/a
Water Consumption (gal/h) <4.0 <4.0 <4.0

Calculated Values

Moisture Weight in Potatoes (lb) 40.35 40.34 40.36
Average Weight of Each Potato (lb) 0.16 0.16 0.16
Cooking Energy (kWh) 2.12 2.12 2.16
Energy Consumed by Potatoes (Btu) 4,891 4,982 4,920

Energy to Food (Btu/lb) 101.8 103.7 102.4

Energy Consumed by Pans (Btu) 234.09 236.2 235.95
Energy of Boiler Re-init (Btu) n/a n/a n/a
Energy Consumed by the Steamer (Btu) 7,234 7,234 7,370
Energy to Steamer (Btu/lb of food cooked) 150.6 150.6 153.4

Cooking Energy Rate (kW) 5.06 5.09 5.19
Productivity (lb/h) 114.9 116.8 116.8
Energy Efficiency (%) 70.9 72.1 70.0

5011.03.23 D-4
Food Service Technology Center

Cooking-Energy Efficiency Data

Table D-5. Light-Load Potatoes Data

Replication 1 Replication 2 Replication 3

Measured Values

Number of Pan(s) 1 1 1

Cook Time (min) 18.25 17.83 17.83

Temperature of Uncooked Potatoes (°F) 73.7 73.2 70.2
Temperature of Cooked Potatoes (°F) 195.0 195.0 195.0
Weight of Stainless-Steel Pans (lb) 2.41 2.40 2.82
Weight of Potatoes (lb) 8.00 8.00 8.00
Total Potato Count 50 50 50
Moisture Content (%) 84 84 84
Condensate Temperature (°F) n/a n/a n/a
Water Consumption (gal/h) <4.0 <4.0 <4.0

Calculated Values

Moisture Weight in Potatoes (lb) 6.72 6.72 6.72
Average Weight of Each Potato (lb) 0.16 0.16 0.16
Cooking Energy (kWh) 0.84 0.84 0.82
Energy Consumed by Potatoes (Btu) 815.25 819.38 838.37

Energy to Food (Btu/lb) 101.9 102.4 104.8

Energy Consumed by Pans (Btu) 36.84 36.62 43.77
Energy of Boiler Re-init (Btu) n/a n/a n/a
Energy Consumed by the Steamer (Btu) 2,866 2,866 2,798
Energy to Steamer (Btu/lb of food cooked) 358.3 358.3 349.7

Cooking Energy Rate (kW) 2.77 2.84 2.78
Productivity (lb/h) 26.3 26.9 26.9
Energy Efficiency (%) 29.7 29.9 31.5

5011.03.23 D-5
Food Service Technology Center

Cooking-Energy Efficiency Data

Table D-6. Frozen Green Pea Cooking-Energy Efficiency and Production Capacity Statistics.

Cooking-Energy Efficiency Production Capacity
Heavy Load Light Load

Replicate #1 92.7 60.0 95.2
Replicate #2 91.1 61.7 94.4
Replicate #3 90.8 60.6 93.9

Average 91.5 60.8 94.5

Standard Deviation 1.02 0.86 0.66
Absolute Uncertainty 2.53 2.13 1.64
Percent Uncertainty 2.77% 3.50% 1.73%

Table D-7. Red Potato Cooking-Energy Efficiency and Production Capacity Statistics.

Cooking-Energy Efficiency Production Capacity
Heavy Load Light Load

Replicate #1 72.1 31.5 116.8
Replicate #2 70.9 29.9 114.9
Replicate #3 70.0 29.7 116.8

Average 71.0 30.4 116.2

Standard Deviation 1.05 0.99 1.10
Absolute Uncertainty 2.60 2.45 2.73
Percent Uncertainty 3.66% 8.06% 2.35%

5011.03.23 D-6
Food Service Technology Center