ISO 20690:2018
(Main)Graphic technology — Determination of the operating power consumption of digital printing devices
Graphic technology — Determination of the operating power consumption of digital printing devices
ISO 20690:2018 provides requirements and recommendations for measuring the electricity consumption of small-format and wide-format digital production presses printing in different modes of operation. It is intended for use on equipment that has been declared by the manufacturer to be suitable for use as a digital production printing press. ISO 20690:2018 provides a means to compare the energy efficiency figures according to two or more characteristic machine combinations: Best Quality (BQ), Best Productivity (BP) or other combinations. ISO 20690:2018 is not suitable for determining the power consumption of individual device components such as servos, fans, compressors, control boards and so on. It excludes digital presses designed to print textiles intended for clothing or machines, which similarly depend on additional processes to produce the printed product, such as ceramics.
Technologie graphique — Lignes directrices pour déterminer la consommation électrique des dispositifs d'impression numérique
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INTERNATIONAL ISO
STANDARD 20690
First edition
2018-02
Graphic technology — Determination
of the operating power consumption
of digital printing devices
Technologie graphique — Lignes directrices pour déterminer la
consommation électrique des dispositifs d'impression numérique
Reference number
ISO 20690:2018(E)
©
ISO 2018
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ISO 20690:2018(E)
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ISO 20690:2018(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General conditions . 5
4.1 Condition, age and machine combination . 5
4.2 Connection conditions . 6
4.3 Printing conditions and operational modes . 7
4.3.1 General. 7
4.3.2 Measurements required for energy efficiency . 7
4.3.3 Measurements required for power consumption . 8
4.4 Measuring conditions . 8
4.5 Measurement cycle . 8
4.6 Calculation and documentation of measurement results .11
Annex A (normative) Measurement data sheet .13
Annex B (informative) Operating power consumption measurement procedures for digital
printing devices .17
Bibliography .23
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ISO 20690:2018(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: www .iso .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 130, Graphic technology.
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ISO 20690:2018(E)
Introduction
Estimates of operating costs for digital printing devices often include a calculation of energy
consumption. However, energy efficiency comparisons are currently impossible to make, as there is no
standard reference for their calculation.
It is common industry practice to estimate energy usage based solely on the connected load of a machine.
This is not a very reliable method, however, as this means that, in many cases, the calculated values
(e.g. 70 % of the power consumption) do not reflect the actual usage of the machine and its energy
[7] [8]
consumption . Actual energy consumption often differs significantly from the estimated values .
Using these methods, power consumption data across devices can, therefore, not be compared, since the
calculations have not followed a common framework that takes into account the influence of peripheral
equipment such as IR or UV dryers and measurement cycles. This document provides requirements for
the measurement of the parameters needed to estimate the energy efficiency (e.g. 1 000 A4 sheets/kWh)
that correspond to the actual energy consumption for a defined machine combination.
This document specifies a method for the estimation of energy efficiency for digital production printing
presses, also known as professional digital printing presses. It is up to the manufacturer of a digital
printing system to declare whether it is suitable for use as a digital production printing press and, in
such cases, this document is applicable.
Specifications to calculate the energy consumption of conventional sheet-fed and web-fed offset
[5] [6]
machines and office equipment exist and are widely used. This document is therefore, not
applicable for the calculation of energy efficiency of conventional sheet-fed and web-fed offset printing
machines, or for office equipment.
The universal availability of accurate and verifiable energy consumption data will enable printing
machinery buyers, printers and their customers to assess the energy efficiency of digital production
printing presses. However, the user of this document should understand that the effectiveness of power
does not dictate quality acceptance levels of the expected output that a customer may require. Power
consumption is an important part of all the output requirements and quality standards necessary for
maintaining the quality and repeatability required by the print buyer. Energy efficiency can be reported
in various ways, such as the number of prints printed per kWh, or as the amount of energy required in
kWh to produce a specific number of prints. This information can be used to
— assess the power consumption and energy efficiency of machines including peripheral devices,
— estimate operating costs for investment planning,
— benchmark energy efficiency of digital production presses,
— measure energy efficiency improvements of digital printing devices over time or for dedicated
process variations, and
— provide data to enable companies to claim environmental subsidies, when replacing equipment
with more energy efficient equipment.
This document defines how to calculate the electrical energy requirements and thus the energy
efficiency of digital printing devices.
When comparing the results obtained from this document, care should be taken that the devices being
compared were set up to produce the same print quality using comparable types of printing technology,
process and device configurations. This document may not be suitable for all devices, such as those
resulting from continuous developments. It is intended to be revised as the technology evolves.
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INTERNATIONAL STANDARD ISO 20690:2018(E)
Graphic technology — Determination of the operating
power consumption of digital printing devices
1 Scope
This document provides requirements and recommendations for measuring the electricity consumption
of small-format and wide-format digital production presses printing in different modes of operation. It
is intended for use on equipment that has been declared by the manufacturer to be suitable for use as a
digital production printing press.
This document provides a means to compare the energy efficiency figures according to two or more
characteristic machine combinations: Best Quality (BQ), Best Productivity (BP) or other combinations.
This document is not suitable for determining the power consumption of individual device components
such as servos, fans, compressors, control boards and so on. It excludes digital presses designed to print
textiles intended for clothing or machines, which similarly depend on additional processes to produce
the printed product, such as ceramics.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
IEC 60204-1, Safety of machinery — Electrical equipment of machines — Part 1: General requirements
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
electrical energy
E
equivalent to electrical energy converted to other forms of energy (power, light, heat) for the operation
of machines and devices
Note 1 to entry: Electricity generated in this way is calculated using the following formula:
t
2
E =×ut() it()dt
∫
t
1
where u(t) and i(t) are the instantaneous values of voltage and current.
3.2
energy usage
power required for the operation of a given process over time
Note 1 to entry: Energy usage or electric energy consumption is typically measured in watt seconds, kilowatt-
hours or watt-hours; Symbol Ws, kWh or Wh.
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ISO 20690:2018(E)
3.3
connected load
theoretically possible maximum power consumption of a machine, which can be expected when
components of the printing machine are running at maximum load
Note 1 to entry: The connected load is the power specified by the manufacturer and used to rate the electrical
power supply of the printing house (power rating, fuse rating, cable cross section). This ensures fail-safe
operation of the machine under any possible operating condition. Determination of the connected load value has
not been uniformly regulated so machine manufacturers handle it differently.
Note 2 to entry: The connected load should not be used to calculate a device’s actual power consumption. This is
always lower, and in most applications, it is significantly lower.
3.4
operational power consumption
power consumption of a machine in a defined operating condition (operational mode)
Note 1 to entry: Active power, reactive power and apparent power are distinct operational power consumptions.
Typical operating modes are Sleep, Print Ready and Production (also known as active mode).
3.5
active power
P
power available for conversion into other types of power
Note 1 to entry: Mechanical, thermal or chemical power. In general, the active power of a consumer in a periodic
AC voltage system can be determined with the formula
T
PT=×1/(ut)(it)dt
∫ 0
where T is the desired period.
Note 2 to entry: standard unit: watt, kilowatt; symbol: W, kW.
3.6
reactive power
Q
power caused by inductive, capacitive and non-sinusoidal consumers placing additional burden on
supply network
Note 1 to entry: Standard unit: volt ampere reactive; Symbol: var, kvar.
3.7
apparent power
S
geometric sum of active power, P, (3.5) and reactive power, Q, (3.6) and/or the product of the effective
values of voltage and current
Note 1 to entry: It can be calculated as follows:
SU =× I
effeff
Note 2 to entry: With non-ohmic consumers, the apparent power is always higher than the active power. The
electrical connections ought to be sized analogously to the apparent power that can be transferred.
Note 3 to entry: Standard unit: volt ampere, kilovolt-ampere; Symbol: VA, kVA.
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ISO 20690:2018(E)
3.8
power meter
power analyser, which records voltages and currents as continuous values to determine power
parameters
Note 1 to entry: For example, active, apparent and/or reactive power by numerical integration.
Note 2 to entry: These are high precision devices designed for industrial use.
3.9
Sleep mode
period when printing machine is switched on, not printing and operating with lower power than that of
Print Ready mode
Note 1 to entry: A reduced power state that a printing device automatically enters after a set period of inactivity.
Sleep mode permits operation of all product features (including maintenance of network connectivity), albeit
with a possible delay to transition into Print Ready or production mode.
3.10
Print Ready mode
period when printing machine is switched on with all assembled components (pre and post processing
units) ready to print immediately
3.11
production mode
period when printing machine is printing live jobs
Note 1 to entry: A production mode is characterized by a stable power consumption, when the printing machine
is printing in a representative and typical fashion.
Note 2 to entry: The production mode is also known as the steady production mode.
3.12
Raster Image Processor
RIP
device or piece of software which converts coded character data and/or vector data into a raster bit
stream (bitmap)
[SOURCE: ISO 12637-2:2008, 2.115, modified]
3.13
machine combination
software, hardware and print media having a direct influence on the resulting print image quality
EXAMPLE BQ combination = device configuration (hardware) + substrate (media) + print mode (software)
Note 1 to entry: RIP (3.12) and print mode (3.17) settings are examples of machine combination.
Note 2 to entry: When the settings depend heavily on the RIP and printing technology, the machine combination
can also be referred to as the digital printing combination.
3.14
device configuration
physical hardware equipment included in a given production line
3.15
basic device configuration
standard hardware equipment configuration as defined by the manufacturer, owner or user of the
device for the type of printed products or market that the press is being used
3.16
alternative device configuration
physical hardware configuration differing from the basic device configuration
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ISO 20690:2018(E)
3.17
print mode
collection of settings, that are used to control a given device configuration via software (RIP) to enable,
disable or otherwise affect the operation of that device
EXAMPLE Using four colours on a machine capable of seven colours, varying the resolution, changing the
speed, enabling duplex printing.
3.18
alternative print mode
collection of settings different to the print modes used for obtaining the Best Quality (BQ) or Best
Productivity (BP) combinations, and used for defining additional combinations
3.19
imposition
fitting of the maximal number of test images (with no change to size) into the screen, sheet or unit
length without overlapping
3.20
imposition rate
ratio between the area of the imposed test images and the total area of the screen, sheet or unit
length paper
Note 1 to entry: In this document, the imposition rate is used to calculate the equivalent A4 or Letter pages
printed on larger paper formats, regardless of the original image size.
3.21
copies
number of given test forms printed on a substrate, regardless of being printed simplex or duplex
EXAMPLE 100 copies = 100 test forms printed on 100 sheets (simplex) or 50 sheets (duplex) or 100 images of
the test form imposed on the given substrate.
3.22
consistency check
method for determining the stability and validity of two sequential measurements before averaging
the results
EXAMPLE 5% consistency is satisfied when the first result value A and the second result value B meet 0,95 ≤
2A/A+B ≤ 1,05, where result value means reporting value (e.g. XX pages/kWh for Energy Efficiency).
3.23
image quality adjustment
IQ adjustment
modifications made during printing to ensure print image quality that forces the printing system to
pause production for a short period of time
Note 1 to entry: Image quality (IQ) adjustments depend on many parameters, such as test form area coverage or
required quality level.
Note 2 to entry: Some printing devices will make image quality (IQ) adjustments during printing to ensure print
quality, where the devices continue moving without delivering any printouts.
3.24
energy efficiency
ratio or other quantitative relationship between an output of performance, service, goods or energy,
and an input of energy
2
EXAMPLE The energy efficiency of a digital press is reported in m /kWh for large format systems or
numbers of A4 pages per kWh.
[SOURCE: ISO 50001:2011, 3.5.3, modified]
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ISO 20690:2018(E)
3.25
tonal coverage
cumulative colorant percentage
EXAMPLE A full sheet of 100 % deep black in CMYK has a tonal coverage = 400. The colorant coverage is
[1]
defined by the tone value as defined in ISO 12647-1 .
Note 1 to entry: Typical coverages based on one colour plane are: Light – 1 % to 9 %, Medium – 10 % to 35 %,
Heavy – 36 % above.
[SOURCE: XJDF-Specification-2.0 Draft 2017-05-11]
4 General conditions
4.1 Condition, age and machine combination
How much power a digital printing device and peripheral devices consume is subject to many influences
such as the selected print mode, equipment characteristics and their condition, ambient conditions,
selected print speed, additional machine settings and the printing substrates used, especially their
drying requirements.
The operational climate should comply with the following conditions, and the actual conditions shall be
documented.
— Temperature: 20 °C to 25 °C
— Relative air humidity: 45 % to 60 %
Measurement of the operational climate parameters shall be made for the period of printing to be
measured for at least three times throughout the print run, including at the start and at the end of the
power measurement at a distance of 1 m to the front side of the sheet feeder or roller unit, at a height of
1,60 m above floor level.
The manufacturer, owner or user of a printing system shall determine a basic or standard device
configuration that can be used for testing. Where possible, two printing modes Best Quality and Best
Productivity shall be identified. Where this is not possible, a single mode shall be used BQ/BP. For the
purpose of this test, these print modes shall be used for printing and measuring to reflect their influence
on its power consumption and energy efficiency data. Combining the selected device configuration with
the chosen print mode and substrate results in the following machine combinations.
— Best Quality combination: The manufacturer, owner or user of a printing system shall select a
device configuration, print mode and substrate for achieving the best possible saleable print quality.
All colorants of the system shall be used.
— Best Productivity combination: The manufacturer, owner or user of a printing system shall use
the same device configuration as used in the Best Quality combination, with a print mode and
substrate for achieving the highest possible saleable productivity.
— Best Quality/Best Productivity combination: Where the differentiation between a Best Quality
and a Best Productivity combination cannot be made, the manufacturer, owner or user of a printing
system shall use a device configuration with a print mode and substrate for achieving the typical
compromise between Best Quality and Best Productivity.
— Supplemental combination: Using the same device configuration, alternative print modes are
allowed (e.g. monochrome printing of a colour test page on a colour device, printing with four colours
on a device capable of seven colours, changing the print resolution, etc.) and shall be reported as a
Supplemental combination, and labelled such as not to be confused with the mandatory Best Quality
or Best Productivity combinations.
NOTE 1 On a monochrome printing device, monochrome printing is not considered to be a Supplemental
combination, and is intended to be tested in both BQ and BP, or a BQ/BP combination.
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ISO 20690:2018(E)
The absolute colour accuracy shall be measured and reported by using a control strip according to
[4]
ISO 12647-8:2012, 5.2 for all combinations. All patches of the control wedge need to be measured and
[4]
reported, (see A.3). Compliance to 12647-8 is not required.
NOTE 2 The colour accuracy is tested in order to ensure that a minimum level of print image quality is
achieved, and is not intended as a full test of colour accuracy.
[9]
NOTE 3 Colour accuracy of monochrome printers is evaluated using a monochrome test page. Such a test page
can be created following the principles of ISO 15930 (PDF/X) and using a monochrome (Gray) output intent.
Electrophotographic processes have significantly fewer parameters affecting energy efficiency
compared to inkjet printing. However, printing systems are available that allow for a change in print
image quality, e.g. by adding a further colorant. If the printing press to be evaluated does not allow for
a meaningful separation between Best Quality and Best Productivity, one machine combination may be
used. This machine combination shall be labelled Best Quality/Best Productivity (BQ/BP).
All equipment needed to produce printed sheets shall be included in the assessment.
Alternative device configurations may include additional pre-handling or post-handling, or print
and output enhancement equipment (e.g. sheeting, folding, binding, additional colours, substrate
enhancement or manipulation), under the condition that the additional equipment is built-in as part
of the production line (in-line). Any alternative device configurations shall be seen and reported as a
different device configuration and tested in both a Best Quality and Best Productivity combination as
defined by the user of this document.
4.2 Connection conditions
Digital printing systems incorporating pre-processing and post-processing units, shall use 1-phase
or 3-phase connection, 50 Hz to 60 Hz and 100 V to 650 V. The power supply quality and the voltage
tolerance shall comply with IEC 60204-1 or equivalent.
Measurements shall be performed on all outlets used by the printing system. Typical connection
points are:
— main printing unit (main switch cabinet);
— paper feeder of the press;
— paper delivery unit;
— external cooling units that can be directly attributed to the printing system;
— digital front end (RIP);
— viewing cabinet.
All units that are required for printing but that can’t be attributed directly to the printing press (e.g.
a centralized pressure, air conditioning or cooling system) shall be estimated using averaged power
consumption values provided by the manufacturer. The method used and the results shall be reported.
For units which can be directly attributed but for which power consumption varies with outside
temperatures, the actual temperature shall be reported. The average annual energy consumption based
on an average temperature of 10 °C and 20 °C should also be reported.
EXAMPLE A chiller or air conditioning unit, mounted on the roof of a printing site, might be connected
directly or indirectly to a press, but its power consumption relies on the outside temperature. While for
an outside temperature of about 30 °C, with the device constantly in operation, it might run only a fraction
of that time during outside temperatures of about 10 °C or less. In order to account for this effect, the power
consumption can be estimated for two temperatures that provide orientation for different (cooler or warmer)
ambient. To accomplish this, one would conduct power measurements or deduce the power measurement based
on manufacturer data sheet provided for the temperatures around 10°C and 20°C. When performing power
measurements, the recommended measurement time is at least 1 h.
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ISO 20690:2018(E)
4.3 Printing conditions and operational modes
4.3.1 General
The printing conditions, including the substrate used, shall be based on the machine’s best quality and
highest productivity modes, and may also cover additional machine operational modes. All modes shall
be documented in conformance with Annex A.
For printing, an unscaled 1 page PDF test form shall be used. The test form shall contain technical and
pictorial elements, with an area coverage up to 40 % per channel, calculated by using tone value data
[1]
as defined in ISO 12647-1 . A colour wedge for conducting the absolute colour accuracy test according
[4]
to ISO 12647-8:2012, 5.2 shall be used. The used colour wedge shall be part of the PDF test form. It is
suggested to use recognized test forms, such as the Fogra test files (2016_ISO20690_LTR_Testfile.pdf,
[9]
2016_ISO20690A4_Testfile.pdf, 2016_ISO20690A3_Testfile.pdf) . The PDF file for the test form shall
be in A4, Letter or A3 format. The test form used shall be documented by means of an icon or miniature
picture alongside the measurement data sheet. Two-sided printing (duplex) may also be used. When
two-sided printing is used, the same image shall be printed on both sides of the sheet, and the printed
pages shall be included in the calculation of printed area or number of copies.
NOTE The Fogra test charts reflect typical graphic arts use cases and therefore, have significantly more
area coverage than typical direct mail applications.
Large format presses are defined as those designed for A2 media and larger, including those designed
to accommodate continuous-form media greater than or equal to 406 mm wide. Duplex printing may be
used by means of the optional machine combinations, and the reporting of such shall cover this in an
unambiguous manner. For large format presses, the pages shall be imposed to fill at least 66 % of the
total available substrate width. The imposition rate shall be taken into consideration (see 4.6).
For small and large format printing, unless it can be reliably demonstrated that the consistency criteria
can be met in a shorter
...
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