Work Paper Abstract
Commercial Door-Type Dishwashers
Revision # 3
California Technical Forum
WP Abstract Prepared by:
Matt Guernsey, Navigant Consulting, Inc.
Chan Paek, So Cal Gas.
High-Efficiency Commercial Door-Type
Dishwashers
Abstract
WP Abstract Tracking Log
7/10/14
8/1/14
1
2
Author
(last
name)
Paek
Roecks
7/24/14
1
Paek
3
Paek
Date Issued
Circulated to TF Members
Cal TF summarizes comments
Abstract presented at Meeting;
consensus decision-marking
Cal TF finalizes abstract;
Revised to incorporate Cal TF
comments from Version 2
Cal TF finalizes abstract;
prepares comparison exhibit of
non-consensus items
Abstract to TF Subcommittee
8/7/14
Due By
8/8/14
Version
8/7/2014
Table 1. Work Paper Abstract Snapshot
Item
Measure name
Measure description
Sector (Res/Non-Res)
Subsector (e.g. Ag)
Program(s)
Work Paper Abstract Snapshot
Details
High efficiency commercial
door-type dishwashers
Commercial door-type
dishwashers that sanitize
dishes with either high- or lowtemp methods;
Non-Res
Food Service
Non-Res deemed rebate for
ROB/NC
Notes
Measure Description
Commercial door-type dishwashers, both low-temp and high-temp models, come in a wide
range of efficiencies. Even among models that meet the ENERGY STAR V2.0 specification
(effective January 2013), performance varies widely. The key driver of energy savings is water
consumption. The most efficient models on the market consume less than 0.5 gallons of hot
water per rack of dishes. Much of the savings therefore comes from reduced water savings at
the establishment’s hot water heater, and not from reduced energy use in the unit itself.
Figure 0-1 shows an example unit.
Cal TF – Work Paper Abstract
Commercial Door-Type Dishwashers
8/1/14
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Figure 0-1: Example commercial door-type dishwasher (source: www.restaurantsource.com)
The measure is applicable to commercial food service operations, primarily full service
restaurants. While some fast food restaurants may use dishwashers, their needs will be very
limited as most dishwashing is for pots and pans that can be done in sinks. Larger operations,
such as hotel kitchens, prisons, and cafeterias, typically use larger conveyor and flight-type
equipment due to greater dish loads and therefore are also not applicable.
Key Terms
Door-Type dishwashers are also known as “pull-down-hood” or “stationary rack” dishwashers;
the former name comes from the way the unit opens, with the door sliding vertically upwards,
while the latter name comes from the fact that the operator manually places a single rack in the
unit and removes it manually after the cycle is complete.
Door-type dishwashers sanitize the dishes during a final rinse phase of the operating cycle and
can use one of two methods:
 Low Temperature Sanitizing – the final rinse uses hot water at approximately 140°F and
in addition to a chemical sanitizing agent; these models typically use more hot water per
rack than high temperature models.
 High Temperature Sanitizing – the final rinse uses hot water at approximately 180°F to
sanitize the dishes; water is typically heated to the final temp using an electric resistance
booster water heater inside the dishwasher.
Test method used to determine performance of dishwashers is ENERGY STAR Test Method for
Commercial Dishwashers (Rev. May-2012).
Energy Star Requirements for Door-Type dishwashers:
Cal TF – Work Paper Abstract
Commercial Door-Type Dishwashers
8/1/14
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Program Implementation Method
The intended delivery method for this measure is a prescriptive rebate with two components:
 Midstream rebate to distributors/suppliers
 Downstream rebate directly to customers
The target market will be foodservice industry and commercial kitchen facilities. Measure
delivery will not differ across regions.
The intended application types are ROB and NC.
Mixed Baseline
This is a single-technology measure.
Below table provides the baseline water consumptions used for engineering calculation.
Baseline
Water Consumption*
CDW Type
High Temp
Low Temp
Units**
1.32
2.10
GPR
Single Tank Door Type
GPR = Gallons per rack.
*See Table 4 on draft WP by PG&E1 in Apppendix A.
The source of the baseline consumption in above table is the NSF listings for non-Enery Star
qualified dishwashers. Per Cal TF comments in Section 17 and 18 of this document, this
baseline data will be verified and adjusted to reflect more appropriate end use consumption and
will be included in the workpaper.
Measure Summary
Table 2. Measure Summary
Characteristic
Cal TF – Work Paper Abstract
Commercial Door-Type Dishwashers
Measure
8/1/14
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Baseline Technology or Mix
Measure Technology
Measure Application Type
Delivery Mechanism
Impacted Markets
Relevant Codes and Standards
Conventional door-type dishwasher
Door-type ENERGY STAR V2.0 specifications
ROB, NC
Prescriptive rebate –
Midstream and/or Downstream
Commercial restaurants
ENERGY STAR V2.0 specifications
Estimated Size of Offer (Number of Participants)
300-500 participants (installed base in SCG territory is approximately 17,000 units) are
estimated. Annual sales are approximately 1,400. For details, refer to Section 2.3.2 in
Navigant’s WP draft under Appendix A.2
Estimated Impact of the Measure on Statewide Energy
Efficiency Savings.
The technical savings potential for this measure (assuming 100% adoption) is approximately 11
million therms per year. In a 3 year program, a reasonable savings estimate is 0.3 to 0.4 million
therms (excluding savings from future years). The measure is not expected to reach 1% of total
portfolio savings to become a high impact measure.
Applicable DEER
There is no DEER measure for commercial dishwashers. Dishwasher measures in DEER
(Appl-Dishwash-StdSize-260-EAEU & Appl-Dishwash-StdSize-180-EAEU) are only for
residential dishwashers.
Proposed Measure Parameter Data and Sources
The following data is based on ENERGY STAR V2.0 performance for water consumption 0.89
and 1.18 gallons per rack for high-temp and low-temp models, respectively.
Table 3. Proposed Measure Parameter Data and Sources
Measure
Parameter
Savings –
kWh
Savings –
kW
1
Data
High-Temp:
796 kWh/yr
Low-Temp:
264 kWh/yr
High-Temp:
1.8 kW
Source Description1
Modification
of DEER or
reason for
not using
DEER
Confidenc
e Level
(High,
Medium,
Low)
Draft WP by PG&E 1
(Section 2, Calculation
Method)
N/A
Medium
Draft WP1
Sec. 2.2
N/A
Medium
Provide a link to source or embed source in Appendix A of this document with page numbers specified.
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Commercial Door-Type Dishwashers
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Low-Temp:
Savings –
therm
EUL or
RUL
High-Temp:
224 therms/yr
Low-Temp:
346 therms/yr
15
High-Temp:
$1,000
MC or IMC
Low-Temp:
$200
NTG
0.70
Draft WP by PG&E 1
(Section 2, Calculation
Method)
N/A
Medium
ENERGY STAR savings
calculator assumption 3
N/A
Medium
Costs for all commercial
dishwashers covered by
ENERGY STAR. Preliminary
estimate based on ENERGY
STAR savings calculator
N/A
Low –
additional
analysis
may be
valuable
prior to
finalizing
data
Assumed for new commercial
default
All ComDefault>=2yr
s
High
* As a reference, see the analysis worksheet “Navigant Analysis” in Appendix A4
As noted in Cal TF Comments, a further investigation on demand reduction will be needed in
order to distinguish between direct peak demand reduction and coincident diversity factor. Also,
the suggestion to consider the monitoring the site will be evaluated during the workpaper
development.
During the workpaper development phase, the energy savings for the measure will be estimated
for each of 16 climate zones using the recent weather data (ground water temperatures)
provided by the Commission Staff.
Proposed Measure Parameter Methodology Sources
The baseline is a ‘typical’ unit, which we calculated based on the average per-rack usage of all
the available units in the NSF International database. Then, using EPA-developed usage
parameters for days/year, racks/day, and hours/day, we calculate the baseline energy
consumption. The usage parameter assumptions include:
 Warewashing load: 203 racks/day
 Annual operation: 360 days/year
 Daily Operation: 12 hours/day
 Baseline gas water heater Energy Factor (EF): 0.80 (gas only)
For the measure’s energy consumption, the average gallons-per-rack usage of Energy Star
qualifying units corresponds to a maximum of 0.71 and 0.99 gallons per rack for high-temp and
low-temp models, respectively.
Table 4. Proposed Measure Parameter Methodology and Sources
Cal TF – Work Paper Abstract
Commercial Door-Type Dishwashers
8/1/14
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Measure
Parameter
Savings – kWh
Savings – kW
Savings – therm
EUL or RUL
MC or IMC
NTG
Modification of
DEER or reason
for not using
DEER
Confidence
Level
(High, Medium,
Low)
N/A
Medium
N/A
Medium
N/A
Medium
N/A
Medium
ENERGY STAR
product listing
N/A
Medium
Assumed for new
commercial default
All ComDefault>=2yrs
High
Source
Description2
Methodology
Draft WP1
Sec. 2.1
Draft WP1
Sec. 2.2
Draft WP1
Sec. 2.3
15
Estimated
relative to
baseline
ENERGY STAR
0.70
DEER
Engineering
Calculation
Engineering
Calculation
Engineering
Calculation
ENERGY STAR
savings calculator3
Proposed Level of Complexity
Consideration of the combinations of primary/booster water heating fuel (electric vs gas) and
appropriately design of delivery mechanism may alter the electric/gas savings claim.
Preliminary TRC Estimates
Table 5. Preliminary TRC Estimates and Parameters
TRC Parameter
Parameter Estimate
or
Required Parameter
Value Threshold
(specify if estimate or
threshold)
High Temp:
796 kWh/yr
224 therms/yr
UES
Confidence Level
(High, Medium,
Low)
Comments
Medium
Low Temp:
264 kWh/yr
346 therms/yr
High Temp: $2100
IMC
EUL
NTG
Incentive/unit
Number of units
Installation Rate
2
Medium
Low Temp: $2000
15
0.7
$1000
170
100%
Medium
High
Medium
Medium
Medium
To be determined by PA
8% penetration assumed
Provide a link to source or embed source in Appendix A of this document with page numbers specified.
Cal TF – Work Paper Abstract
8/1/14
Commercial Door-Type Dishwashers
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Gross Realization
Rate
1.0
TRC Value:
High
~1.5 Confidence Level - Medium
*See the preliminary TRC calculation in Appendix A5.
Questions for CPUC Staff on Applicability of DEER
Values, Methods, Tools, Data, Etc.
An increase of qualifying efficiency requirement may need to be considered to promote higher
efficiency units that perform 15% ~ 40% better then Energy Star Requirements.6 This
consideration will be discussed with the program administrators to determine the qualifying
efficiency for the workpaper.
Additional Research Needed
Cost data - Additional analysis may be valuable prior to workpaper development.
Rack per day – It was suggested by Cal TF that this assumption should be representative of the
usage of the industry and be based on credible justification. The consideration of monitoring or
surveying for this data was suggested by Cal TF.
Booster Heater – Verify the arrangement of the washer’s booster heater (integrated/separate)
and identify the source of the fuel source penetration of the primary-booster water heating
combination.
Research on the most current available models, their specs, and the market penetration of
major brands/models were also suggested by the Cal TF.
Applicable EM&V
No recent EM&V study was found on this subject.
Workpaper Development
The initial draft workpapers from Navigant and Food Service Technology Center are included in
appendix A1,2. Additional work will be required to update the workpaper to reflect the comments
from Cal TF. Food Service Technology Center will continue developing the workpaper for this
measure, and Cal TF’s comments will be addressed appropriately.
Cal TF – Work Paper Abstract
Commercial Door-Type Dishwashers
8/1/14
Page 7
This page to be completed by Cal TF Staff
Cal TF Comments on Proposed Measure Parameter Data
and Sources
Table 6. Cal TF Comments on Measure Parameter Data and Sources
Measure
Parameter
Savings – kWh
Cal TF Comments on
Proposed Data/Source
Double check source for baseline
consumption values, particularly
racks/day to ensure they are
industry representative and are
based on credible justification. If
need be, consider other sources
such as ASHRAE for racks/day
assumption, or consider
monitoring as part of measure
implementation to establish
credible racks/day assumption.
Ensure data for non-qualifying
dishwasher models are from a
reasonable date.
Cal TF Recommendation(s) on
Alternate Sources to Consider
Savings – kW
Savings – therm
EUL or RUL
MC or IMC
NTG
Cal TF Comments on Proposed Measure Parameter
Methodology and Sources
Table 7. Cal TF Comments on Measure Parameter Methodology and Sources
Measure
Parameter
Savings – kWh
Savings – kW
Cal TF Comments on
Proposed Data/Source
A straight average for the
baseline case may not be
appropriate – a baseline derived
from industry standard practice
or a sales weighted average may
be more appropriate if it can be
determined based on food
service industry interviews or
other market research.
Distinguish between direct peak
demand reduction and coincident
diversity factor. If peak demand
reduction and CDF are difficult to
Cal TF – Work Paper Abstract
Commercial Door-Type Dishwashers
Cal TF Recommendation(s) on
Alternate Sources to Consider
8/1/14
Page 8
This page to be completed by Cal TF Staff
determine, consider including
monitoring component in
measure to bolster initial
workpaper assumptions.
Savings – therm
EUL or RUL
MC or IMC
NTG
Cal TF Comments on Proposed Level of Complexity
Cal TF – Work Paper Abstract
Commercial Door-Type Dishwashers
8/1/14
Page 9
This page to be completed by Cal TF Staff
Commission Staff Review and Feedback
Commission staff should provide feedback on proposed data and sources within 10 days of
request.
Table 8. Commission Staff Feedback on Proposed Data and Sources
Measure
Parameter
Savings – kWh
Savings – kW
Date Sent to
Staff
Date Staff
Responded
Commission Staff Comment
Savings – therm
EUL or RUL
MC or IMC
NTG
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Commercial Door-Type Dishwashers
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This page to be completed by the Abstract Developer
Appendix A – Sources
1 Technical workpaper draft by PG&E ( Food Service Technology Center)
PGECOFSTNEW_Rev0_Dishwashers_07102014.docx
2 Technical workpaper draft by Navigant
ENERGY STAR V2
Commercial Door-Type Dishwashers - Technical Workpaper 2014-01-22.docx
3 ENERGY STAR savings calculator available:
www.energystar.gov/buildings/sites/default/uploads/files/commercial_kitchen_equipment_ca
lculator.xlsx
4 Navigant Analysis worksheet
Navigant Analysis.xlsx
5 TRC Calculator
TRC_Calculation_CommercialDishwasher.xlsx
6 Ultra-high efficiency option above Energy Star
POF - ESTAR V2 Door-Type Dishwasher - Ultra-high Efficiency Options 2014-05-21.pptx
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