ENERGY STAR Symbol

ENERGY STAR®
Qualifying Criteria for
Commercial Dishwashers

Version 1.2 – January 2011

A product shall meet all of the identified criteria if it is to earn the ENERGY STAR symbol.

1) Definitions

A. Dishwashing Machine
A machine designed to clean and sanitize plates, glasses, cups, bowls, utensils, and trays by applying sprays of detergent solution (with or without blasting media granules) and a sanitizing final rinse.

B. Under Counter Dishwasher
A machine with an overall height 38 inches (97 cm) or less, in which a rack of dishes remains stationary within the machine while being subjected to sequential wash and rinse sprays, and is designed to be installed under food preparation workspaces. Under counter dishwashers can be either chemical or hot water sanitizing, with an internal booster heater for the latter.

C. Stationary Rack, Single Tank, Door Type Dishwasher
A machine in which a rack of dishes remains stationary within the machine while subjected to sequential wash and rinse sprays. This definition also applies to machines in which the rack revolves on an axis during the wash and rinse cycles. Subcategories of stationary door type machines include: single and multiple wash tank, double rack, pot, pan and utensil washers, chemical dump type and hooded wash compartment (“hood type”). Stationary rack, single tank, door type models can be either chemical or hot water sanitizing, with an internal or external booster heater for the latter.

D. Single Tank Conveyor Dishwasher
A warewashing machine that employs a conveyor or similar mechanism to carry dishes through a series of wash and rinse sprays within the machine. Specifically, a single tank conveyor machine has a tank for wash water followed by a final sanitizing rinse and does not have a pumped rinse tank. This type of machine may include a pre-washing section before the washing section. Single tank conveyor dishwashers can be either chemical or hot water sanitizing, with an internal or external booster heater for the latter.

E. Multiple Tank Conveyor Dishwasher
A conveyor type machine that has one or more tanks for wash water and one or more tanks for pumped rinse water, followed by a final sanitizing rinse. This type of machine may include one or more pre-washing sections before the washing section. Multiple tank conveyor dishwashers can be either chemical or hot water sanitizing, with an internal or external booster heater for the latter.

F. Hot Water Sanitizing (High Temp) Machine
A warewashing machine that applies potable hot water to the surfaces of wares to achieve sanitization.

G. Chemical Sanitizing (Low Temp) Machine
A warewashing machine that applies potable water and a chemical sanitizing solution to the surfaces of wares to achieve sanitization.

H. Product Family:
Variations of one model offered within a single product line with design differences limited to: finish/color; length of pre-wash section, and orientation (e.g., corner, straight through models). Individual models represented by a product family must have the same rinse water and idle energy consumption.

2) Scope:

A. Included Products:
Products that meet the definition of a Commercial Dishwasher as specified herein are eligible for ENERGY STAR qualification, with the exception of products listed in Section 2.B. The following product types are eligible: undercounter; stationary rack, single tank, door type; single tank conveyor; and multiple tank conveyor. Only those undercounter machines designed for wash cycles of 10 minutes or less are eligible for ENERGY STAR. Pot, pan, and utensil machines may qualify for ENERGY STAR under the stationary rack, single tank, door type requirements.

B. Excluded Products:
Flight-type machines are not eligible for ENERGY STAR under this specification. Commercial dishwashers that include an optional manual rinse, after the final sanitizing rinse, are in violation of current NSF Standards and therefore, are not eligible for ENERGY STAR.

3) Qualification Criteria:

A. Energy and Water Efficiency Requirements:

Table 1: Efficiency Requirements for Commercial Dishwashers
Machine
Type
High Temp Efficiency Requirements Low Tem Efficiency Requirements
Tank Heater Idle Energy Rate* Water Consumption Tank Heater Idle Energy Rate* Water Consumption
Under
Counter
≤ 0.90 kW ≤ 1.00 gal/rack
(≤ 3.79 litres/rack)
≤ 0.50 kW ≤ 1.70 gal/rack
(≤ 6.44 litres/rack)
Stationary
Single Tank
Door**
≤ 1.0 kW ≤ 0.950 gal/rack
(≤ 3.6 l/rack)
≤ 0.60 kW ≤ 1.18 gal/rack
(≤ 4.47 l/rack)
Single Tank Conveyor ≤ 2.0 kW ≤ 0.700 gal/rack
(≤ 2.65 l/rack)
≤ 1.6 kW ≤ 0.790 gal/rack
(≤ 2.99 l/rack)
Multiple Tank Conveyor ≤ 2.6 kW ≤ 0.540 gal/rack
(≤ 2.04 l/rack)
≤ 2.0 kW ≤ 0.540 gal/rack
(≤ 2.04 l/rack)

* Idle results should represent tank heater idle energy rate measured with door closed.
**Includes pot, pan, and utensil machines.


B. High/Low Temperature Machines:
Machines designed to be interchangeable in the field from high temp to low temp, and vice versa, shall meet both the high temp and low temp requirements of Table 1 to qualify as ENERGY STAR.

C. Calculations for Determining Gallons per Rack Results:
The following calculations shall be used to determine gallons per rack. These calculations are based on gallons per rack conversions provided in the NSF Products and Service Listing for commercial dishwashers at www.nsf.org.

  Conveyor Type
GPR = GPH X RL
CS X 60

  Door Type
GPR = GPH X (WT + RT +DT + LT)
3600

Load Time= 5 seconds for straight through door-type dishwashers.
Load Time= 7 seconds for corner door-type dishwashers.
Load Time= 30 seconds for front load/unload dishwashers

  Undercounter Type
GPR = GPH X (WT+RT+DT+LT)
3600

Load time= 30 seconds for undercounter dishwashers.

WT= Wash Time in seconds.
RT= Rinse time in seconds.
DT= Dwell time in seconds.
RL= Rack length, use 20x20 in.
LT= Load time
CS= Maximum conveyor speed in feet per minute
GPH= Water use in gallons per hour.

D. Significant Digits and Rounding:
  1. All calculations shall be carried out with actual measured or observed values. Only the final result of a calculation shall be rounded. Calculated results shall be rounded to the nearest significant digit as expressed in the corresponding specification limit.
  2. Unless otherwise specified, compliance with specification limit shall be evaluated using exact values without any benefit from rounding.

4) Test Requirements:

A. Representative Models shall be selected for testing per the following requirements:
  1. For qualification of an individual product model, the representative model shall be equivalent to that which is intended to be marketed and labelled as ENERGY STAR.
  2. For qualification of a product family, any model within that product family can be tested and serve as the representative model.

B. When testing commercial dishwashers, the following test methods shall be used to
    determine ENERGY STAR qualification:


Table 2: Test Methods for ENERGY STAR Qualification
E NERGY STAR Requirement Test Method Reference
Gallons per Rack (GPR) NSF/ANSI 3-2007 Standard, Commercial Warewashing Equipment
Idle Energy Rate – Undercounter and Stationary Rack, Single Tank, Door Type ASTM Standard F1696, Standard Test Method for Energy Performance of Single-Rack Hot Water Sanitizing, Door-Type Commercial Dishwashing Machines*
Idle Energy Rate – Single and Multiple Tank Rack Conveyor Dishwashers ASTM Standard F1920, Standard Test Method for Energy Performance of Rack Conveyor, Hot Water Sanitizing, Commercial Dishwashing Machines*

* Although the titles of the ASTM test procedures listed above specifically call out hot water sanitizing machines, the idle energy rate portion is also applicable, and shall be used, for chemical sanitizing machines.

5) Effective Date

The ENERGY STAR Commercial Dishwasher Specification shall take effect on October 11, 2007. To qualify for ENERGY STAR, a product model shall meet the ENERGY STAR specification in effect on the model’s date of manufacture. The date of manufacture is specific to each unit and is the date (e.g., month and year) on which a unit is considered to be completely assembled.

6) Future Specification Revisions

ENERGY STAR reserves the right to change the specification should technological and/or market changes affect its usefulness to consumers, industry, or the environment. In keeping with current policy, revisions to the specification are arrived at through industry discussions. In the event of a specification revision, please note that the ENERGY STAR qualification is not automatically granted for the life of a product model.

  1. ASTM Test Standard Review: ENERGY STAR plans to revisit this specification once the revision processes for ASTM F1696 and ASTM F1920 are complete. These test methods will address energy consumption in various modes of operation as well as water consumption.

  2. Review of Idle Energy Requirements: Within two years of this specification becoming effective, ENERGY STAR will review idle energy data to determine whether the limits provided in Table 1 provide for sufficient differentiation in the marketplace. If it is determined that revisions are needed, ENRGY STAR will work closely with industry stakeholders to develop appropriate new levels.