Melink EF 1 User Manual
Design & Engineering Services
Demand Control Ventilation for Commercial
Kitchen Hoods
ET 07.10 Report
Prepared by:
Design & Engineering Services
Customer Service Business Unit
Southern California Edison
June 30, 2009
Demand Control Ventilation for Commercial Kitchen Hoods ET 07.10
Acknowledgements
Southern California Edison’s Design & Engineering Services (D&ES) group is responsible for
this project. It was developed as part of Southern California Edison’s Emerging Technology
program under internal project number ET 07.10. D&ES project manager Angelo Rivera
conducted this technology evaluation with overall guidance and management from Paul
Delaney. For more information on this project, contact Angelo.Rivera@sce.com.
Disclaimer
This report was prepared by Southern California Edison (SCE) and funded by California
utility customers under the auspices of the California Public Utilities Commission.
Reproduction or distribution of the whole or any part of the contents of this document
without the express written permission of SCE is prohibited. This work was performed with
reasonable care and in accordance with professional standards. However, neither SCE nor
any entity performing the work pursuant to SCE’s authority make any warranty or
representation, expressed or implied, with regard to this report, the merchantability or
fitness for a particular purpose of the results of the work, or any analyses, or conclusions
contained in this report. The results reflected in the work are generally representative of
operating conditions; however, the results in any other situation may vary depending upon
particular operating conditions.
Southern California Edison
Design & Engineering Services June 2009
Demand Control Ventilation for Commercial Kitchen Hoods ET 07.10
ABBREVIATIONS AND ACRONYMS
MUA Make-Up Air
cfm Cubic Feet Per Minute
DCV Demand Control Ventilation
HVAC Heating Ventilation and Air Conditioning
IR Infrared
MDL Micro Data Loggers
CT Current Transducers
FLA Full Load Amps
hp Horse Power
SF Supply Fan
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FIGURES
Figure 1 Commercial Kitchen Exhaust Hood Styles1..........................4
Figure 2 Commercial Kitchen MUA Configuration types2...................5
Figure 3 Melink Intelli-HOOD HARDWARE (Court esy of Melink®).........7
Figure 4 Melink Intelli-Hood Heat and Smoke Detection (Courtesy
of Melink
Figure 5 Monitoring Equipment Installation ...................................10
Figure 6 Typical Demand Usage for EF 160 at Desert Springs
Marriott ...................................................................18
Figure 7 Typical Demand Usage for EF 8 at The Westin Mission Hills .20
Figure 8 Typical Demand Usage for EF 1,2,3 at El Pollo Loco............22
Figure 9 Typical Demand Usage for EF 1 at Panda Express..............24
Figure 10 Typical Demand Usage fro EF 1 at Farmer Boys...............26
Figure 11 Desert Springs Marriott Hood 1 System A.......................28
Figure 12 Desert Springs Marriott Hood 2 System A.......................29
Figure 13 Desert Springs Marriott Hood 3 System A.......................29
Figure 14 Desert Springs Marriott Hood 1 System B.......................30
Figure 15 Desert Springs Marriott Hood 2 System B.......................30
Figure 16 Desert Springs Marriott Hood 3 System B.......................31
Figure 17 Typical Demand Usage for EF 159 at Desert Springs
Marriott ...................................................................31
®
).................................................................8
Figure 18 Typical Demand Usage for EF 161 at Desert Springs
Marriott ...................................................................32
Figure 19 Typical Demand Usage for EF 162 at Desert Springs
Marriott ...................................................................32
Figure 20 Typical Demand Usage for EF 163 at Desert Springs
Marriot.....................................................................33
Figure 21 Typical Demand Usage for EF 164 at Desert Springs
Marriott ...................................................................33
Figure 22 Westin Mission Hills Hood 1 ..........................................34
Figure 23 Westin Mission Hills Hood 2 ..........................................35
Figure 24 Westin Mission Hills Hood 3 ..........................................36
Figure 25 Typical Demand Usage for EF 7 at Westin Mission Hills .....36
Figure 26 Typical Demand Usage for EF 9 at Westin Mission Hills .....37
Figure 27 Typical Demand Usage for EF 10 / MUA at Westin Mission
Hills.........................................................................37
Figure 28 Typical Demand Usage for SF 2 at Westin Mission Hills .....38
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Figure 29 Typical Demand Usage for SF 3 at Westin Mission Hills .....38
Figure 30 El Pollo Loco Hood 1 ....................................................39
Figure 31 El Pollo Loco Hood 2 ....................................................40
Figure 32 Typical Demand Usage for MUA at El Pollo Loco...............40
Figure 33 Panda Express Hood 1 .................................................41
Figure 34 Panda Express Hood 2 .................................................42
Figure 35 Typical Demand Usage for EF 2 / MUA at Panda Express...42
Figure 36 Farmer Boys Hood 1....................................................43
Figure 37 Farmer Boys Hood 2....................................................44
Figure 38 Farmer Boys Hood 3....................................................45
Figure 39 Typical Demand Usage for EF 1 at Farmer boys...............45
Figure 40 Typical Demand Usage for EF 2 at Farmer Boys...............46
TABLES
Table 1 Overall Field Evaluation Results..........................................2
Table 2 Overall Field Evaluation Results For All Sites ......................15
Table 3 Desert Springs Marriott Exhaust Fan Results ......................16
Table 4 Desert Springs Marriott MUA Results.................................17
Table 5 Westin Mission Hills Results.............................................19
Table 6 El Pollo Loco Results.......................................................21
Table 7 Panda Express Results....................................................23
Table 8 Farmer Boys Results.......................................................25
EQUATIONS
Equation 1 Percentage Average kW Reduction...............................14
Equation 2 Average Daily Operational Hours .................................14
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CONTENTS
EXECUTIVE SUMMARY _______________________________________________ 1
INTRODUCTION ____________________________________________________ 3
Objective .............................................................................. 3
CONFIGURATIONS _________________________________________________ 4
Baseline................................................................................5
Demand Control Ventilation System..........................................6
Hardware.........................................................................6
Controls...........................................................................7
APPROACH_______________________________________________________ 9
Monitoring Equipment.............................................................9
TEST SITE DESCRIPTIONS_____________________________________________ 11
Desert Springs Marriott.........................................................11
Westin Mission Hills..............................................................12
El Pollo Loco........................................................................12
Panda Express.....................................................................12
Farmer Boys........................................................................13
RESULTS AND DISCUSSION___________________________________________ 14
Desert Springs Marriott.........................................................15
Westin Mission Hills..............................................................18
El Pollo Loco........................................................................20
Panda Express.....................................................................23
Farmer Boys........................................................................25
CONCLUSIONS ___________________________________________________ 27
Recommendations................................................................27
APPENDIX A – DESERT SPRINGS MARRIOTT ______________________________ 28
Kitchen Hood Description..................................................28
PPENDIX B – WESTIN MISSION HILLS__________________________________ 34
A
Kitchen Hood Description..................................................34
A
PPENDIX C – EL POLLO LOCO ______________________________________ 39
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Kitchen Hood Description..................................................39
A
PPENDIX D – PANDA EXPRESS ______________________________________ 41
Kitchen Hood Description..................................................41
APPENDIX E – FARMER BOYS ________________________________________ 43
Kitchen Hood Description..................................................43
REFERENCES _____________________________________________________ 47
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EXECUTIVE SUMMARY
Commercial kitchen hoods (hoods) are a significant componen t of energy consumption in
restaurant and fast-food kitchens. They function to reduce fire hazards and exhaust cooking
effluent to comply with air quality standards within a commercial kitchen. Exhaust hoods in
these kitchens are normally tied to a make-up air (MUA) unit that balances building
pressure during the kitchens operation. Generally, the hoods’ exhaust requirements are
sized to peak cooking usage of each appliance under the hood. Typical hoods have a simple
“on” or “off” control strategy. When the hood is on, its exhaust and make up air fans are on
at full speed or not at all. In reality food is not being cooked at all times t herefore not
needing the peak exhaust requirements. Due to the common control strategies employed in
most commercial kitchens a significant amount of energy is wast ed on venting unnecessary
cubic feet per minute of air when appliances are not fully used. It is evident that there is an
opportunity for energy efficient savings. The Melink Int elli-Hood demand control ventilation
system (DCV) is an energy management system for commercial kitchen hoods. It optimizes
energy efficiency by reducing the exhaust and make up air fan speed. This is accomplished
by leveraging an infrared and temperature sensors to determine the minimum amount of
exhaust air required to capture and contain effluent from the cookline.
The primary objective of this project is to verify field performance and demonstrate how the
Melink Intelli-Hood demand control ventilation (DCV) system can reduce energy costs. The
projects secondary objective is to evaluate the market sectors impacts on field performance
and energy reduction on a DCV system. The different market sectors can have different
hours of operation, appliances, and kitchen exhaust hood configurations. For this field
evaluation two hotels and three quick-service restaurants were chosen. Also in this field
evaluation only the exhaust and make up air fan motor energy savings were accounted for.
Air conditioning savings, due to heat load reduction in the kitchen area, were not accounted
for.
The Melink Intelli-Hood DCV system was shown to significantly reduce the energy
consumption and electrical demand associated with operating a commercial kitchen exhaust
hood.
daily energy consumption, annual energy consumption, annual savings, percentage energy
usage reduction, and estimated annual operational cost for all hood data at each site. The
savings results from the Melink Intelli-Hood DCV system installation can realize a 37-62%
energy savings over current commercial kitchen hoods. The DCV system was most effective
in the hotel market sector due to the amount of hoods, amount of HP servicing the hotel,
and the hours of operations. Hotel kitchens are sized for peak food production - defined as
the maximum food prepared at any given time in a hotel’s kitchen. The hotel’s kitchen
sizing also means there are multiple hoods and higher amounts of HP needed to meet the
maximum food demands. Since maximum food demands rarely happen, the hotel market
sector has a high potential for savings. Most of the time there is limited kitchen use
occurring in a given day, allowing a DCV system to save energy by running at minimal
exhaust settings.
Table 1 lists the average kW draw, percentage reduction, daily operational values,
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In the quick-service restaurant market sector there was a large percentage energy drop at
each site, but a significantly lower energy savings. The lower energy savings were attributed
to the lower hp motors, operational time, appliance usage, and amount of hoods. In
addition to energy savings, with the installation of a DCV system, there was the added
benefit of noise reduction from the kitchens’ exhaust hood system.
This evaluation also showed that the performance of the DCV system was highly impacted
by the different appliance types and their controls. The appliance types ranged from lightduty to extra heavy-duty. The opportunity for energy savings decreased as the appliances
duty rating got closer to extra heavy-duty rated appliances. The higher the rating the higher
the heat load and more effluent the appliance created during cooking. The opportunity for
savings also decreased when the appliances controls created a constant heat load when
either in use or not in use. Appliances that only produce heat when cooking gave a large
opportunity for savings.
TABLE 1 OVERALL FIELD EVALUATION RESULTS
Overall Results For All Sites
Average demand without DCV
system (kW)
Average demand with DCV
system (kW)
Average kW reduction (%)
Daily Operational Hours
Daily energy usage without
DCV system (kWh/day)
Daily energy usage with DCV
system (kWh/day)
Annual energy usage without
DCV system (kWh/yr)
Annual energy usage with
DCV system (kWh/yr)
Annual energy savings with
DCV system (kWh/yr)
Percentage energy usage
reduction (kWh/yr)
Estimated annual operational
savings (@$0.15 a kWh)
Desert Springs
Marriott
Westin
Mission Hills
El Pollo
Loco
Panda
Express
Farmer
Boys
27.9 12.1 4.7 5.2 2.9
10.7 5.2 2.9 2.0 1.4
61.6% 57.0% 38.3% 61.5% 51.7%
24 24 15.36 13.1 15.83
670 291 72 67 44
257 125 45 26 23
244,500 106,034 26,313 24,620 16,159
93,681 45,595 16,442 9,559 8,276
150,819 60,439 9,871 15,061 7,884
61.7% 57.0% 37.5% 61.2% 48.8%
$22,623 $9,066 $1,481 $2,259 $1,183
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INTRODUCTION
Commercial kitchen hoods are a significant component of energy consumption in
commercial kitchens. They function to reduce fire hazards and exhaust cooking effluent to
comply with air quality standards within a commercial kitchen. Exhaust hoods in
commercial kitchens are normally tied to a make-up air (MUA) unit that balances building
pressure during the kitchens operation. Generally, commercial kitchen hoods exhaust
requirements are sized to peak cooking usage of each appliance under the hood. Typical
commercial kitchen hoods have a simple “on” or “off” control strategy. When the hood is on,
its exhaust and MUA fans are on at full speed or not at all. In reality food is not being
cooked at all times therefore not needing the peak exhaust requirements. Due to the
common controls strategies employed in most commercial kitchens a significant amount of
energy was wasted on venting unnecessary cubic feet per minute of air (cfm) when
appliances were not fully used. It was evident that there was an opportunity for change. A
demand control ventilation system (DCV) is an energy management system for commercial
kitchen hoods. It optimizes energy efficiency by reducing the exhaust and MUA fan speed.
This is accomplished by leveraging sensors to determine the minimum amount of exhaust
air required to capture and contain effluent from the cookline.
Derived from the SCE service territory database there are 37,212 restaurants, 5,553 hotels,
3,313 grocery stores, 9,105 schools/colleges, and 1,076 hospitals. Within the SCE service
territory there is a total of 56,156 customers with the potential to use DCV systems. Within
California it is estimated there are 124,040 restaurants, 18,510 hotels, 11,043 grocery
stores, 30,553 schools and 3,243 hospitals. Within all of California it is estimated there is a
total of 187,187 customers with the potential to use DCV systems. This was estimated by
assuming SCE has 30%, PGE has 35%, SDGE has 20% and municipal utilities have 15% of
Californians total customer utility service. For some market segments the applicability of the
DCV technology might be as low as 50% and as high as 80%.
OBJECTIVE
The Primary objective of this project is to verify field performance and demonstrate
how the Melink Intelli-Hood demand control ventilation (DCV) system can reduce
energy costs. The project’s secondary objective is to evaluate the market sectors’
impact on field performance and energy reduction using a DCV system. The different
market sectors can have different hours of operation, appliances, and kitchen
exhaust hood configurations.
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CONFIGURATIONS
Commercial kitchen exhaust hoods can come in many different configurations. These
varying configurations can impact the hoods ability to capture and contain effluent,
including odors, gases, heat, and oil. The better the system is designed, the lower the cfm
needed to capture effluent and the lower the energy consumption of the kitchen exhaust
hood. The hood style, construction features, and proximity of hood installation, give
different capture areas, dictating the necessary exhaust cfm. The hood styles, in order from
highest exhaust requirement to least, generally include; single-island canopy hood, wallmounted canopy hood, double-island canopy hood, and back-shelf hood, as depicted in
Figure 1.
FIGURE 1 COMMERCIAL KITCHEN EXHAUST HOOD STYLES1
The appliances and the food being cooked under the hood can factor in the exhaust cfm
requirements. Cooking appliances are categorized as light, medium, heavy, or extra heavyduty, due to their strength of thermal plumes it can create. Thermal plume strength is also
affected by the type of food being cooked on the appliance. The stronger the thermal plume
the more exhaust cfm that is required.
Configuration of how MUA is introduced into the kitchen is also an important configuration.
MUA balances the pressure of the kitchen when exhaust fans are in operation. As air is
exhausted out of the hood, the air is replaced by an equal volume of air. Typically, a
dedicated MUA unit is employed in a commercial kitchen. A dedicated MUA unit only makes
up a percentage of the air exhausted. By not matching cfm exhausted air, the kitchen keeps
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a negative pressure. The remaining air volume, not replaced by the MUA unit, is taken from
transfer air such as the dining area or a kitchens’ air handlers system. A small negative
pressure is desired to keep the kitchens odors from transferring into other areas the kitchen
is connected to. If no MUA is introduced, kitchen pressure may become too negative and
affect the capture and containment of effluent. When designing a dedicated MUA system for
a commercial kitchen, how the air is introduced into the kitchen can factor into how much
exhaust air to replace, and can affect the kitchen hoods ability to capture and contain
affluent. A poorly designed MUA system with a high exhaust replacement cfm can make a
kitchen hood perform poorly. Poorly designed MUA systems can hinder effluent or push
effluent outside of the hoods containment area and into the kitchen space. MUA can be
untreated (air taken from outside), or treated air (evaporative cooled or heated air). When
MUA is introduced into the kitchen it has the abil ity to save Heating, Ventilation and Air
Conditioning (HVAC) energy. This is accomplished by reducing the amount of conditioned air
being exhausted. The most common configuration to introduce MUA into the kitchen is
through integrated hood plenums. The different integrated hood plenums types in order of
worst design to best are: short circuit, air curtain supply, front face supply, perforated
perimeter supply, back wall supply, or any combination of integrated hood plenum types as
depicted in Figure 2.
FIGURE 2 COMMERCIAL KITCHEN MUA CONFIGURATION TYPES2
BASELINE
For this field evaluation the baseline for each site was a commercial kitchen hood
with the simple “on” or “off” control strategy. When the hood is “on” both exhaust
and make-up air units are at full speed until turned off. The customers chosen for
this field evaluation were either customer’s who needed the DCV system retrofit to
participate, or customers with an existing DCV system installed. At sites where the
DCV system was a retrofit, electrical usage was logged. At sites where the DCV
system was already installed, the keypad was used to override the DCV system
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before monitoring electrical usage. By overriding the DCV system, the simple “on” or
“off” controls of the kitchen exhaust hood was restored to measure baseline data for
the hood.
DEMAND CONTROL VENTILATION SYSTEM
The Melink Intelli-Hood DCV system was selected for this field evaluation because, at
the time, it was the only commercially available DCV system. Although other
manufacturers are in the process of developing their DCV systems, none were
available at the time of this study. The Melink Int elli-Hood DCV system is an energy
management system for commercial kitchen exhaust hoods. It can be installed in
new construction or as a retrofit. The Intelli-Hood controls optimize energy efficiency
by reducing the exhaust and MUA fan speed by leveraging sensors to determine the
amount of exhaust air required to capture and contain effluent from the cookline.
Since cooking does not occur at a constant, the kitchen exhaust and MUA fans vary
their speed using a variable speed controller to meet the necessary minimum
exhaust air requirements. This allows the exhaust system to run at the lowest
possible speed to perform the required job. In addition, the noise level in the kitchen
is reduced significantly as the system decreases the exhaust and MUA fan speed
during low exhaust demand.
HARDWARE
The Melink Intelli-Hood system consists of 6 pieces of hardw a re as illustrated in
Figure 3.
- I/O Processor receives inputs from the temperature sensor and optic sensor.
With the inputs received from the sensors, the processor controls the output of
the electronic motor starters. The processor also displays current operations of
each hood and is able to be programmed by the keypad.
- Temperature Sensor monitors the exhaust air temperature in the exhaust duct.
A temperature signal is transmitted to the I/O processor that uses the signal to
vary the speed in proportion to actual heat load.
- Optic Sensors monitor the presence of smoke and vapors inside the hood. With
the presence of smoke and/or vapors, a signal is sent to the I/O processor to
ramp fans to full speed to remove it.
- Air Purge Units are miniature blowers that are equipped on both the optical
transmitter and receiver to prevent grease from collecting on the optical sensor
lenses when the kitchen hood exhaust system is operating.
- Electric Motor Starter is a variable frequency drive equipped on each exhaust
and Make-up fan motor. The electric motor starter receives the signal from the
I/O processor then adjusts the motor speed to meet each hood’s needs.
- Keypad allows users to turn on the system and displays current system fan
levels. The keypad also gives the user programming capabilities for the system.
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FIGURE 3 MELINK INTELLI-HOOD HARDWARE (COURTESY OF MELINK®)
CONTROLS
The Melink Intelli-Hood system I/O processor is the brain for the whole system. The
I/O processor has the ability to control up to 4 exhaust fan motors and its
corresponding MUA units. The I/O processor displays current system fan levels for
each hood it controls on the keypad. The keypad is how different system parameters
are configured, such as electric motor starter speed rate for corresponding
temperature ranges and Infrared (IR) beam strength. The I/O processor receives
exhaust duct temperature signals for each hood from temperature sensors. The
different appliances under the hood produce heat load whether they are in use or on
stand-by. The electric motor starter varies the exhaust fan and MUA motor
depending on the temperature signal received and where it falls in the programmed
temperature parameters as illustrated in Figure 4
receiver and transmitter. The optical sensor is mounted in the bottom center on each
side of the hood. The transmitter transmits a red IR beam across the hood and when
the receiver receives intensities of less than 95% of fu ll input, a signal is sent to the
I/O processor. Usually smoke or vapors from the cookline are the cause of the
obstructions. When the signal is received the I/O processor runs the exhaust and
MUA fans at full speed, regardless of the exhaust ducts temperature, to remove
obstructions to the optical sensor as illustrated in .
. The optical sensor consists of a
Figure 4
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The Melink Intelli-Hood different paramete rs are tailored and programmed dependent
on the configuration of the kitchen. Configurations such as hood length, hood type,
hood design, how MUA is introduced, appliance exhaust requirements, and type of
food being cooked play an important role on the different parameters. The
parameters are programmed with kitchen configurations in mind during system
commissioning to achieve optimized performance and energy savings.
Heat and Smoke
FIGURE 4 MELINK INTELLI-HOOD HEAT AND SMOKE DETECTION (COURTESY OF MELINK®)
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APPROACH
To evaluate the field performance and demonstrate how the Melink Intelli-Hood DCV system
can reduce energy costs, each customer’s kitchen exhaust and MUA fan motor electrical
usage was monitored. In this evaluation only the exhaust and MUA fan motor energy
savings were measured. Since HVAC savings are weather dependent, cooling load reduction
savings were not accounted for due to the complexity it would bring to this field evaluation.
To determine potential energy savings realized by the Melink Intelli-Hood system at each
site, three phases were completed.
- Phase 1 - Baseline evaluation: After the customer sites were chosen to
participate in the field evaluation, the kitchen configuration was noted. The
different exhaust and MUA fan motors were found and corresponding electrical
service breakers were found. Fan motors name plate data was also recorded. A
Micro Data logger was installed on each exhaust and MUA electrical breaker to
monitor electrical usage of the corresponding fan motor. At sites where the DCV
system was a retrofit, electrical usage was logged. At sites where the DCV
system was already installed, the keypad was used to override the DCV system
before monitoring electrical usage. By overriding the DCV system, the simple
“on” or “off” controls of the kitchen exhaust hood were restored to measure
baseline data for the hood. Since the motors ran constantly at full speed under
the baseline controls of the kitchen hoods, the power draw from each fan motor
was pretty much constant. Baseline data was recorded for about one week at
each site and analyzed.
- Phase 2 - System retrofit or adjustment: After each kitchen exhaust hood
electrical usage was baselined, phase two was initiated. At sites where the simple
“on” or “off” controls strategy was employed, the DCV system hardware was
installed and system parameters were programmed during commissioning. At
sites where the DCV system was already installed, the keypad was used again to
restore the DCV system controls.
- Phase 3 - New system evaluation: After installation or adjustment of the DCV
system, the system was allowed to run for two weeks to ensure proper
performance. The DCV system’s electrical usage was monitored for about six
weeks in the quick-service restaurants and twelve weeks in the hotels.
MONITORING EQUIPMENT
Micro Data Loggers, (MDL) Current Transducers, (CT) and wattnodes were also
installed in the electrical breaker servicing each exhaust and MUA fan motor at all
five sites as shown in Figure 5. The MDL logs power data coming from a wattnode.
The wattnode generates pulses from voltage readings tapped into the circuit and
amperage readings from CTs (generically, Power=voltage x amperage). Electrical
service for each fan motor was either three phase 480v delta or three- phase 208v
wye. When monitoring three phase 480v delta circuits, a WNA-3D-480P wattnode
was used. When monitoring three phase 208v wye-wired circuits, a WNA-3Y-208P
wattnode was used. The wattnode has an accuracy of
scale through 25th harmonic.
Maximum amperage draw of each fan motor dictated the CT size used for monitoring
CTs used for each of the sites were either 5 or 20 amps.
0.45% of reading + 0.05% of full
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each motors electrical full load amps (FLA). The CTs has an accuracy of ±1% at 10%
to 130% of rated current
Power data was measured in 15-second intervals and averaged into 5-minute data
points logged by the MDL. A low sample interval was chosen to provide high
accuracy and resolution for the readings. The compiled 5-minute data was
downloaded monthly. A Fluke 43B power quality analyzer was used to verify data
collected. Spot checks were also administered each time data was downloaded and
the logger was reset.
FIGURE 5 MONITORING EQUIPMENT INSTALLATION
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