Efficiency of domestic electrical storage water heaters and testing methods

This European Standard specifies methods for measuring the performance of electric storage water
heaters for the production of sanitary hot water for household and similar use.
The object is to state and define the principal performance characteristics of electric storage water
heaters and to describe the test methods for measuring these characteristics.
NOTE 1 This standard does not apply to;
− storage water heaters that use electricity as a secondary source of heating the water;
− storage water heaters that do not use a tank to storage hot water;
− electric storage water heaters that do not meet the minimum (or maximum) output performance of the smallest (or biggest)
load profile, as defined in Table 4.
NOTE 2 This standard does not specify performance or safety requirements. For safety requirements see EN 60335-1 in
conjunction with EN 60335-2-21.

Wirkungsgrad von elektrischen Warmwasserspeichern für den Hausgebrauch

Efficacité des chauffe-eau électriques à accumulation

La présente Norme européenne spécifie des méthodes de mesure de l’aptitude à la fonction des chauffe-eau électriques à accumulation pour la production d'eau chaude sanitaire à usage domestique et analogue.
Elle a pour objet de préciser et de définir les principales caractéristiques d’aptitude à la fonction des chauffe-eau électriques à accumulation et de décrire les méthodes d'essai pour la mesure de ces caractéristiques.
NOTE 1 La présente norme ne s'applique pas aux:
-   chauffe-eau à accumulation qui utilisent l'électricité en tant que source secondaire de chauffage de l'eau;
-   chauffe-eau à accumulation qui n'utilisent pas un réservoir de stockage d'eau chaude
-   chauffe-eau électriques à accumulation qui ne répondent pas au rendement minimal (ou maximal) du plus petit (ou plus grand) profil de charge, tel que défini dans le Tableau 4.
NOTE 2 La présente norme ne spécifie pas les exigences en matière d’aptitude à la fonction ou de sécurité. Pour les exigences de sécurité, voir l’EN 60335-1 conjointement avec l'EN 60335-2-21.

Učinkovitost gospodinjskih električnih akumulacijskih grelnikov vode in preskusne metode

Ta evropski standard določa metode za merjenje učinkovitosti električnih akumulacijskih grelnikov vode za pripravo tople vode za gospodinjstva in za podobno uporabo. Namen je navesti in opredeliti glavne značilnosti delovanja električnih akumulacijskih grelnikov vode ter opisati preskusne metode za merjenje teh značilnosti.
OPOMBA 1: Ta standard se ne uporablja za:
– akumulacijske grelnike vode, ki uporabljajo elektriko kot pomožni vir ogrevanja vode;
– akumulacijske grelnike vode, ki ne uporabljajo rezervoarjev za akumulacijo vroče vode;
– električne akumulacijske grelnike vode, ki ne izpolnjujejo minimalne (ali maksimalne) zmogljivosti izhoda najmanjšega (ali največjega) profila obremenitve, kot je opredeljen v preglednici 4.
OPOMBA 2: Ta standard ne določa zahteve glede učinkovitosti ali varnostnih zahtev. Za varnostne zahteve glejte EN 60335-1 v povezavi z EN 60335-2-21.

General Information

Status
Published
Public Enquiry End Date
31-Aug-2014
Publication Date
13-Dec-2015
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
02-Dec-2015
Due Date
06-Feb-2016
Completion Date
14-Dec-2015

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Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 50440:2016
01-januar-2016
8þLQNRYLWRVWJRVSRGLQMVNLKHOHNWULþQLKDNXPXODFLMVNLKJUHOQLNRYYRGHLQ
SUHVNXVQHPHWRGH
Efficiency of domestic electrical storage water heaters and testing methods
Wirkungsgrad von elektrischen Warmwasserspeichern für den Hausgebrauch
Efficacité des chauffe-eau électriques à accumulation
Ta slovenski standard je istoveten z: EN 50440:2015
ICS:
91.140.65 Oprema za ogrevanje vode Water heating equipment
SIST EN 50440:2016 en,fr
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 50440:2016

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SIST EN 50440:2016

EUROPEAN STANDARD EN 50440

NORME EUROPÉENNE

EUROPÄISCHE NORM
November 2015
ICS 91.140.65
English Version
Efficiency of domestic electrical storage water heaters and
testing methods
Efficacité des chauffe-eau électriques à accumulation et Effizienz von elektrischen Warmwasserspeichern für den
méthodes associées Hausgebrauch
This European Standard was approved by CENELEC on 2015-10-05. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.



European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2015 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
 Ref. No. EN 50440:2015 E

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SIST EN 50440:2016
EN 50440:2015 (E)
Content
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Symbols and Units . 5
5 Calculation of the electrical energy efficiency (h ) . 6
elecwh
6 Measured parameters . 6
7 General conditions for measurements . 6
8 Reference conditions . 7
9 Test procedures . 9
10 Data Report .18
Annex A (normative) Calculation of the specific energy efficiency and of the Annual
Consumption of electric energy .19
Annex ZZA (informative) .21
Annex ZZB (informative) .22
Bibliography .23
2

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SIST EN 50440:2016
EN 50440:2015 (E)

European foreword
This document (EN 50440:2015) has been prepared by CLC/TC 59X "Performance of household and
similar electrical appliances".
The following dates are fixed:
• latest date by which this document has
(dop) 2016-10-05
to be implemented at national level by
publication of an identical national
standard or by endorsement
• latest date by which the national
(dow) 2018-10-05
standards conflicting with this
document have to be withdrawn

Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such
patent rights.
This document has been prepared under a mandate given to CENELEC by the European Commission
and the European Free Trade Association, and supports essential requirements of EU Directive(s).
For the relationship with EU Directives see informative Annexes ZZA and ZZB, which are integral
parts of this document.
3

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SIST EN 50440:2016
EN 50440:2015 (E)
1 Scope
This European Standard specifies methods for measuring the performance of electric storage water
heaters for the production of sanitary hot water for household and similar use.
The object is to state and define the principal performance characteristics of electric storage water
heaters and to describe the test methods for measuring these characteristics.

NOTE 1 This standard does not apply to;
− storage water heaters that use electricity as a secondary source of heating the water;
− storage water heaters that do not use a tank to storage hot water;
− electric storage water heaters that do not meet the minimum (or maximum) output performance of the smallest (or biggest)
load profile, as defined in Table 4.
NOTE 2 This standard does not specify performance or safety requirements. For safety requirements see EN 60335-1 in
conjunction with EN 60335-2-21.
2 Normative references
Not applicable.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
storage water heater
water heater that uses electric heating elements as the means of heating water for long-term storage
in a thermally insulated container and provided with a device to control the water temperature
3.2
primary function
to heat water for the production of hot water for household and similar needs
3.3
energized storage water heater
storage water heater that is designed to supply hot water and energised for 24 h per day
3.4
off-peak storage water heater
storage water heater that is designed to supply hot water whilst only being supplied with electrical
energy at off-peak/low tariff periods
Note 1 to entry: The off-peak storage water heater is required to fulfil the requirements of the tapping pattern between 7:00h
and 22:00h without external energy supply, e.g. to enable operation at off-peak/low-tariff periods and/or to operate in conditions
of insecurity of energy supply. A product qualifies as “off-peak” if it is only energized for a maximum of 8 consecutive hours
anywhere between 22:00h and 7:00h during the test with the 24h tapping pattern.
3.5
load profile
means the output performance (in terms of flow-rates, temperatures, tapping pattern, etc.) of a storage
water heater when fulfilling its primary function under specific ambient conditions (see Tables 3 and 4),
as declared by the manufacturer
4

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SIST EN 50440:2016
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3.6
energy efficiency
means the ratio between the delivered energy in the sanitary hot water for its load profile and the
consumed electrical energy
3.7
storage volume
rated quantity of water stored in the appliance
Note 1 to entry: This is declared in litres.
3.8
smart control
device that automatically adapts the water heating process to individual usage conditions with the aim
of reducing energy consumption
3.9
out of the box-mode
standard operating condition, setting or mode set by the manufacturer at factory level, to be active
immediately after the appliance installation, suitable for normal use by the end-user according to the
water tapping pattern for which the product has been designed and placed on the market
4 Symbols and Units
Table 1 – Symbols
Unit Description
Symbol
[%] Energy efficiency of a storage water heater.
h
elecwh
Q [kWh] Reference energy for the 24 h tapping pattern for the load profile of the water
ref
heater.

Q [kWh] Electricity consumption with the relevant 24 h tapping pattern.
elec
[°C]
θ´ mean water temperature for the determination of θ , measured at the outlet
p p
f [l/min] Minimum flow rate which hot water is contributing to the reference energy as
specified in Table 4.
T [°C] The water temperature at which hot water starts contributing to the reference
m
energy as specified in table 4
T [°C] Minimum water temperature to be achieved during water draw off as specified
p
in Table 4
Q [kWh] Measured electricity consumption over 24 h test (step 4).
testelec
Q Useful energy content of the hot water of n drawn-offs
[kWh]
H2O
full−drawing
Sum of quantity of hot water totally delivered during the tapping period.
[litres]
V
water
V
[litres] Measured volume delivered at the mean water temperature.
40_exp
°
V
[litres] Mixed water quantity delivered at 40 C.
40
C [litres] Actual capacity of Water Heater
act
m [kg] Actual weight of water contained inside the tank of the Water Heater
act
smart Presence or not of smart control (value shall be 0 or 1).
SCF Efficiency gain by smart control function.

5

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SIST EN 50440:2016
EN 50440:2015 (E)
5 Calculation of the electrical energy efficiency (h )
elecwh
The electrical energy efficiency (h ) of a storage water heater is the ratio between the delivered
elecwh
energy in the hot water for the tapping pattern of its load profile and the consumed energy. The
consumed energy is the result of the test of the water heater with adjustments for:
− smart control that can reduce the energy consumption

The electrical energy efficiency of a storage water heater shall be calculated as Formula 1:
Q
ref
h =
(1)
elecwh
Q (1−SCF⋅smart)
elec
where:
Q is the delivered energy for the 24 h tapping pattern for the load profile of the water heater,
ref
in kWh;
Q
is the consumption of electric energy with the relevant 24 h tapping pattern, in kWh;
elec
smart indicates the presence of smart control and is yes = 1, no = 0;
NOTE SCF=0 in case no smart control is detected during testing (9.2).
6 Measured parameters
The parameters below shall be established following the measurement methods described in following
Clauses 7 and 9:
a) electricity consumption [kWh/d];
b) electrical energy efficiency [%];
c) storage volume [litre].
7 General conditions for measurements
Measurements shall be carried out with a supply of:
Table 2 – Electricity
Permissible
Uncertainty of
deviation
Measured quantity Unit Value measurement Notes
(average over
(accuracy)
test period)
Electricity
Power W  ± 2 %
energy kWh  ± 2 %
voltage, test-period > 48 h V 230/ 400 ± 4 % ± 0,5 %
voltage, test-period < 48 h V 230/ 400  ± 2 % ± 0,5 %
electric current A  ± 0,5 %
frequency Hz 50 ± 1 %
6

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SIST EN 50440:2016
EN 50440:2015 (E)

Table 3 gives additional test conditions and tolerances for test outputs (i.e. thermal energy).
Table 3 – Test conditions and outputs. Set values and tolerances
Permissible
Permissible
deviations Uncertainty
deviation
of of
Measured quantity Unit Value (average Notes
individual measurement
over test
measured (accuracy)
period)
values
Time
Time s  ± 0,1 s
Maximum interval between samples
s 3
(during the deliver of hot water)
Maximum interval between samples
s 60
(during the no-deliver of hot water)
Sanitary water
cold water temperature °C/ K 10 °C +/- 1 K +/- 1 K +/- 0,5 K*

cold water pressure MPa 0,3 MPa  ± 5 %

a, b
hot water temperature °C/ K pattern  +/- 0,5 K*
volume flowrate l / min pattern  ± 1 %
volume measurements l   ± 0,5 %
± 2 % ± 2 % ± 2 % c
thermal energy kWh pattern
(overall) (or ±10Wh) (or ±10Wh)
Ambient air
Temperature °C/ K 20 °C ± 1 K  ± 1 K
a To be measured by "rapid response thermometer", meaning an instrument that registers within 1 s. at least 90% of the final
temperature rise from 15 to 100 °C when the sensor is plunged in still water.
b Thermocouple with a maximum diameter of 0,5mm, centred in stream, directly at outlet
c Apart from the maximum deviation a correction factor Qref/QH2O is applied, whereby Qref is taken from Table 4 and QH2O
is the energy content of the useful water actually delivered during the test. "Useful water" is water with a temperature higher
than a threshold value Tm for tappings in a profile specified in Table 4.
*Together with the publication task it should be mentioned towards the Commission that this tolerance is hard or
really not to be reached in practice.
All other installation requirements are made according to the manufacturer’s instructions.
8 Reference conditions
Table 4 specifies the tapping patterns for the chosen Load Profile. Parameters in the table are:
a) Load Profile [XXS-4XL, in header row of table];
b) h hour [hh:mm] starting at 0:00 h;
c) Q [kWh] useful energy content of water withdrawal to be achieved in the draw-off;
tap
d) f [l/min] minimum flow rate to be reached during tapping;
e) T [°C] temperature from which counting of useful energy content starts;
m
f) T [°C] minimum (peak) temperature to be achieved during tapping;
p
g) Q [kWh/d] daily (24 h) useful energy content of all water draw-offs, effectively the sum of all
ref
Q .
tap

For all tests a cold water temperature of (10 ± 2) ºC shall be used.
As much as possible, the test method uses a ‘black-box’ approach, i.e. largely technology
independent. This means amongst others that the laboratory uses the original appliance thermostat, in
the position specified by manufacturer, and at the factory settings.
7

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SIST EN 50440:2016
EN 50440:2015 (E)

Table 4 –Load profile of water heater (reference test tapping patterns)
XXS XS S  M L XL  XXL 3XL 4XL
Qtap f Tm Tp Qtap f Tm Tp Qtap f Tm Tp  Qtap f Tm Tp Qtap f Tm Tp Qtap f Tm Tp  Qtap f Tm Tp Qtap f Tm Tp Qtap f Tm Tp
l/mi l/mi
h h
h kWh ºC ºC kWh l/min ºC ºC kWh l/min ºC ºC kWh l/min ºC ºC kWh l/min ºC ºC kWh l/min ºC ºC kWh l/min ºC ºC kWh l/min ºC ºC kWh ºC ºC
n n
07.00 0, 105 2 25   0,105 3 25  07.00 0,105 3 25 0,105 3 25 0,105 3 25  07.00 0,105 3 25 11,2 48 40  22,4 96 40
07.05        07.05 1,400 6 40 1,400 6 40    07.05
      1,820 1,820
07.15   07.15    6 40  07.15 6 40
07.26       07.26     0,105 3 25  07.26 0,105 3 25
07.30 0, 105 2 25 0,525 3 35 - 0,105 3 25  07.30 0,105 3 25 0,105 3 25    07.30
07.45       07.45   0,105 3 25 4,420 10 10 40 07.45 6,240 16 10 40
08.01        08.01 0,105 3 25   0,105 3 25  08.01 0,105 3 25 5,04 24 25  10,08 48 25
08.05       08.05   3,605 10 10 40   08.05
08.15       08.15 0,105 3 25   0,105 3 25  08.15 0,105 3 25
08.25       08.25   0,105 3 25    08.25
08.30 0, 105 2 25   0,105 3 25  08.30 0,105 3 25 0,105 3 25 0,105 3 25  08.30 0,105 3 25
08.45       08.45 0,105 3 25 0,105 3 25 0,105 3 25  08.45 0,105 3 25
09.00       09.00 0,105 3 25 0,105 3 25 0,105 3 25  09.00 0,105 3 25 1,68 24 25  3,36 48 25
0,105 0,105 0,105 0,105 0,105 0,105
09.30 2 25   3 25  09.30 3 25 3 25 3 25  09.30 3 25
10.00       10.00     0,105 3 25  10.00 0,105 3 25
10.30       10.30 0,105 3 10 40 0,105 3 10 40 0,105 3 10 40 10.30 0,105 3 10 40 0,84 24 10 40 1,68 48 10 40
11.00       11.00     0,105 3 25  11.00 0,105 3 25
11.30 0, 105 2 25   0,105 3 25  11.30 0,105 3 25 0,105 3 25 0,105 3 25  11.30 0,105 3 25
11.45 0, 105 2 25   0,105 3 25  11.45 0,105 3 25 0,105 3 25 0,105 3 25  11.45 0,105 3 25 1,68 24 25  3,36 48 25
0,105
12.00 2 25     12.00      12.00
12.30 0, 105 2 25      12.30       12.30
12.45 0,105 2 25 0,525 3 35 - 0,315 4 10 55 12.45 0,315 4 10 55 0,315 4 10 55 0,735 4 10 55 12.45 0,735 4 10 55 2,52 32 10 55 5,04 64 10 55
14.30       14.30 0,105 3 25 0,105 3 25 0,105 3 25  14.30 0,105 3 25
15.00       15.00     0,105 3 25  15.00 0,105 3 25
15.30        15.30 0,105 3 25 0,105 3 25 0,105 3 25  15.30 0,105 3 25 2,52 24 25  5,04 48 25
16.00       16.00     0,105 3 25  16.00 0,105 3 25
16.30        16.30 0,105 3 25 0,105 3 25 0,105 3 25  16.30 0,105 3 25
17.00       17.00     0,105 3 25  17.00 0,105 3 25
18.00 0, 105 2 25   0,105 3 25  18.00 0,105 3 25 0,105 3 25 0,105 3 25  18.00 0,105 3 25
18.15 0, 105 2 25   0,105 3 40  18.15 0,105 3 40 0,105 3 40 0,105 3 40  18.15 0,105 3 40
18.30 0, 105 2 25      18.30 0,105 3 40 0,105 3 40 0,105 3 40  18.30 0,105 3 40 3,36 24 25  6,72 48 25
19.00 0, 105 2 25      19.00 0,105 3 25 0,105 3 25 0,105 3 25  19.00 0,105 3 25
19.30 0, 105 2 25      19.30       19.30
20.00 0, 105 2 25      20.00       20.00
20.30   1,050 3 35 - 0,420 4 10 55 20.30 0,735 4 10 55 0,735 4 10 55 0,735 4 10 55 20.30 0,735 4 10 55 5,88 32 10 55 11,76 64 10 55
20.45 0, 105 2 25      20.45       20.45
   4,420 6,240
20.46      20.46    10 10 40 20.46 16 10 40
21.00 0, 105 2 25      21.00   3,605 10 10 40   21.00
21.15 0, 105 2 25      21.15 0,105 3 25   0,105 3 25  21.15 0,105 3 25
 0,525 1,400 0,105 4,420 6,240 12,04 24,08
21.30    5 45  21.30 6 40 3 25 10 10 40 21.30 16 10 40 48 40  96 40
21.35 0,105 2 25      21.35       21.35
21.45 0, 105 2 25      21.45       21.45
2,100 2,100 2,100 5,845 11,655 19,070 24,530 46,760 93,520
Qref      Qref     Qref
8

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SIST EN 50440:2016
EN 50440:2015 (E)

9 Test procedures
9.1 Standard Test Procedure
9.1.1 Introduction
The following subclauses describe the test procedure to establish the electricity consumption Q
elec
during a 24 h test.
9.1.2 Installation
Install product in test environment according to manufacturer’s instructions.
Designated floor-standing appliances are to be placed on a floor with low thermal leakage (e.g. 20 mm
thick medium density fibreboard could be placed under the test object at a distance of 100 mm above
the floor of the test room).
Wall-mounted products shall be mounted on a panel at least 150 mm from any structural wall with a
free space of at least 250 mm above and below the product and at least 700 mm to the sides.
Products designated to be built-in shall be mounted according to manufacturer’s instructions.
Products with declared Load Profiles 3XL and/or 4XL may be tested on-site, provided test conditions
are equivalent, possibly with correction factors, to the ones referenced here.
9

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SIST EN 50440:2016
EN 50440:2015 (E)




Position of the thermocouples for
Vertical and Horizontal models (   ).






Thermocouple or
5 cm
probe position for

reference thermostat
h/2
h




Circular
Position of thermocouple
welding
or reference probe for
reference thermostat

b) For horizontal water heater

For the horizontal devices, the reference temperature is probed on
the higher generator of the tank, at 5 cm of the circular welding on

the cylindrical part and opposed to the heater.
a) For vertical water heater
Figure 1 – Position of the thermocouples for Vertical and Horizontal models
10

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SIST EN 50440:2016
EN 50440:2015 (E)


Key
1 thermocouple outlet temperature
2 thermocouple cold water temperature
3 measurement flow rate
4 valve bypass
5 safety valve
6 valve tapping
Figure 2 – example of hydraulic connection (unvented products)
Distance between the cold water inlet of the water heater and the position of the thermocouple
measuring cold water shall be lower or equal to 100 mm.
9.1.3 Stabilisation
Keep product at ambient conditions (test room) until all parts of the product have reached ambient
conditions ± 5 K (at least for 24 h).
11

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SIST EN 50440:2016
EN 50440:2015 (E)


Figure 3 – Test procedure Figure 4 – Test procedure
for “ENERGIZED APPLIANCES” for “OFF-PEAK APPLIANCES”
9.1.4 Storage volume
STEP 0 of Figures 3 and 4: the volume of the tank in a storage electric water heater is measured as
follows.
The empty water heater is to be weighted; the weight of taps on inlet and/or outlet pipes shall be
considered.
Then the storage water heater is filled with cold water in accordance with the manufacturer’s
instruction at cold water pressure. The water supply is then cut off.
The filled water heater is to be weighted.
The difference of the two weights (m ) is to be converted into the volume in litres.
act
m
act
C = (2)
act
0.9997
This volume is to be reported in litres to the nearest one-tenth litres. The measured value (actual
value) shall not be more than 2 % lower than the rated value.
9.1.5 Filling and heat-up
STEP 1 of Figures 3 and 4: products with storage-facilities shall be filled with cold water (10 ± 2) °C.
Filling stops at the applicable cold water pressure (see Table 4).
STEP 2 of Figures 3 and 4: the product is energized to reach “out-of-the-box” factory settings, e.g. for
storage temperature. The product’s own means of control (thermostat) shall be used. The next stage
starts at thermostat cut out.
12

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SIST EN 50440:2016
EN 50440:2015 (E)

9.1.6 Stabilisation at zero-load
STEP 3 of Figures 3 and 4: keep the product at normal operating conditions as specified by the
manufacturer without draw-offs during at least 12 h. This stage ends - and next stage starts - at the
first thermostat cut-out after 12 h.
9.1.7 Tapping
STEP 4 of Figures 3 and 4: for the selected Load Profile, draw-offs are made in accordance with the
specifications of the appropriate 24 h tapping pattern in Table 4. Tapping pattern starts directly after
thermostat cut out from stabilisation part with the first tapping at 7:00h time-value as implied in
Table 4. The tapping period ends 24 h later. The required useful energy content of the hot water is the
total Q [in kWh] in Table 4.
ref
During the tapping stage technical parameters (power, temperature, etc.) are established in
accordance with specifications in Table 4. During draw-offs the recommended maximum sample rate
is 3 s (see Table 3). Recorded values shall be part of the technical test report.
Electricity consumption over the 24 h test Q [kWh electricity] will be measured over 24 h (i.e. t -
testelec 5
t ).
3
Useful energy content of the hot water drawn-off Q [kWh] is determined as described below:
H2O
• follows from average in-/outlet temperature difference during the useful tapping period in [K],
the tapped useful water volume in litre. and the specific heat of water c
w
3
(1,163 x 10 kWh/(litre x K)):

Q [i]=∆T[i]×V[i]×c (3)
H2O w

where:

Q [i] is the "Energy content" of one draw-off in [kWh];
H2O
ΔT[i]
is the average in-/outlet temperature difference during the
useful tapping period in [K];
V[i]
is the tapped useful water volume [litres];
-3
c (1,163x10 kWh/(litre x K)) is the specific heat of water.
w


For all the n draw-offs of one tapping profile the energy content is the sum:

Q = Q [i] for i=1to n (4)
H2O ∑ H2O

This formula can have many formats, e.g. more dynamic formats using flowrate and instantaneous
temperature differences, but it comes down to the same result.
Products to be classified as “Off-peak” appliances shall be energized for a maximum period of 8
consecutive hours (t -t ) during 22:00h and 7:00h of the 24 h tapping pattern as specified in Table 4.
5 4
full−drawing
In addition V [litres] will be recorded; it is the sum of quantity of hot water totally delivered
water
during the tapping period.
9.1.8 Reporting of Q
elec
Q shall be corrected for any energy surplus or deficit outside the strict 24 h tapping period, i.e. a
testelec
possible energy difference before and after the tapping cycle is taken into account. Furthermore, any
surplus or deficit in the delivered useful energy content of the hot water is taken into account in the
following equations for Q .
elec
13

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SIST EN 50440:2016
EN 50440:2015 (E)

Q
  1,163×C ×(T(t )−T(t ))
 
ref
act 3 3 5 5
Q = × Q + [kWh] (5)
elec  testelec 
 
Q 1000
 
 H2O
where T and T are water temperatures measured at the dome of water heater, respectively at t and
3 5 3
t .
5
9.1.9 Re-stabilisation at zero-load
STEP 5 of Figures 3 and 4: keep product at nominal operating conditions without draw-offs during at
least 12 h. For products with storage-facilities subject to a control cycle this stage ends at the first
thermostat cut-out after 12 h.
9.1.10 Mixed water quantity delivered at 40 °C
STEP 6 of Figures 3 and 4: quantity of water at 40 °C, which has the same heat content (enthalpy) as
the hot water which is delivered above 40 °C at the output of the water heater.
Immediately following measurement according to “Re-stabilization at zero-load” (STEP 5), the water
heater is switched off after the last cut-out of the thermostat.
Then a quantity of water equal to the rated capacity is withdrawn through the outlet at a constant rate
of flow by supplying cold water; the flow of water from open outlet water-heaters is controlled by the
inlet valve. The flow in any other type of water-heaters is kept constant by means of a valve fitted in
the outlet or the inlet.
The rate of flow is adjusted to the maximum value showed on “Water heater load profile” chosen to
perform the appliance during the tapping cycle.
T [°C] is the water temperature, without withdrawal of water, measured with a thermocouple placed
set
inside the upper section of the tank. For metal tanks the thermocouple may be placed on the outer
surface of the tank as well. This value is the water temperature measured after the last cut-out of the
thermostat during the “Re-stabilization at zero-load” step.
θ [°C] is the average temperature of inlet cold water during the test.
c
θ' [°C] is the average temperature of outlet water and its normalized value is named θ [°C]; it is to be
p p
calculated in according to the following formula:
 
 
θ' −θ
 
p c
 
θ [°C]=(T −10)× +10
(6)


set  
p
T −θ 
 set c

NOTE Temperature readings are preferable taken continuously. Alternatively, they may be taken at equal intervals evenly
spread over the discharge, for example every 5 litres (maximum). If there is a sharp drop in temperature, additional readings
may be necessary in order to correctly calculate the average value θ’ .
p
Outlet water temperature shall always be ≥ 40 °C which is to be taken into account for the calculation
of θ .
p
The volume V [litres] which corresponds to the quantity of water delivered at least 40 °C is to be
40_exp
considered.
Quantity of hot water V [litres] delivered with a temperature of at least 40 °C will be calculated by the
40
following equation:
(θ −10)
p
V [litres]=V ⋅ (7)
40 40exp
30

14

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SIST EN 50440:2016
EN 50440:2015 (E)

9.2 Smart Control Test procedure
9.2.1 Measurement procedure
The Smart Control test procedure is based on two periods of test; they are named “reference period”
and “smart period”. During the first period, “reference period”, the smart control does not influence the
heating procedure and the appliance us
...

SLOVENSKI STANDARD
oSIST prEN 50440:2014
01-junij-2014
1DGRPHãþD
SIST EN 60379:2005
8þLQNRYLWRVWJRVSRGLQMVNLKHOHNWULþQLKDNXPXODFLMVNLKJUHOQLNRYYRGH
Efficiency of domestic electrical storage water heaters
Wirkungsgrad von elektrischen Warmwasserspeichern für den Hausgebrauch
Efficacité des chauffe-eau électriques à accumulation
Ta slovenski standard je istoveten z: prEN 50440:2014
ICS:
91.140.65 Oprema za ogrevanje vode Water heating equipment
oSIST prEN 50440:2014 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN 50440:2014

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oSIST prEN 50440:2014

EUROPEAN STANDARD DRAFT
prEN 50440
NORME EUROPÉENNE

EUROPÄISCHE NORM

May 2014
ICS 91.140.65 Will supersede EN 60379:2004
English Version
Efficiency of domestic electrical storage water heaters and
testing methods
Efficacité des chauffe-eau électriques à accumulation et Effizienz von elektrischen Warmwasserspeichern für den
méthodes d'essai Hausgebrauch
This draft European Standard is submitted to CENELEC members for enquiry.
Deadline for CENELEC: 2014-10-10.

It has been drawn up by CLC/TC 59X.

If this draft becomes a European Standard, CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which
stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CENELEC in three official versions (English, French, German).
A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to
the CEN-CENELEC Management Centre has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.



European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2014 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Project: 16330 Ref. No. prEN 50440:2014 E

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prEN 50440:2014 - 2 -

1 Content
2 Foreword . 3
3 1 Scope . 4
4 2 Normative references . 4
5 3 Terms and definitions . 4
6 4 Symbols and Units . 5
7 5 Calculation of the electrical energy efficiency (η ) . 6
elecwh
8 6 Measured parameters . 6
9 7 General conditions for measurements . 6
10 8 Reference Conditions . 7
11 9 Test procedures . 9
12 9.1 Standard Test Procedure . 9
13 9.2 Smart Control Test procedure .14
14 10 Data Report .17
15 Annex ZZ (informative) Coverage of Essential Requirements of EC Directives .18
16 ZZ.1 Scope .18
17 ZZ.2 Symbols and Units .18
18 ZZ.3 Calculation of the specific energy efficiency (ηwh) and of the Annual Consumption of
19 electric energy .18
20 ZZ.4 Data Report .20
21 Bibliography .21
22
23

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24 Foreword
25 This document [prEN 50440:2014] has been prepared by CLC/TC 59X "Performance of household
26 and similar electrical appliances".
27 This document is currently submitted to the Enquiry.
28 This document will supersede EN 60379:2004.
29 This document has been prepared under a mandate given to CENELEC by the European Commission
30 and the European Free Trade Association, and supports essential requirements of EU Directive(s).
31 For the relationship with EU Directive(s) see informative Annex ZZ, which is an integral part of this
32 document.

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33 1 Scope
34 This European Standard specifies methods for measuring the performance of electric storage water
35 heaters for the production of sanitary hot water for household and similar use.
36 The object is to state and define the principal performance characteristics of electric storage water
37 heaters and to describe the test methods for measuring these characteristics.
38
39 NOTE 1 This standard does not apply to;
40 − storage water heaters that use electricity as a secondary source of heating the water;
41 − storage water heaters that do not use a tank to storage hot water
42 − electric storage water heaters that do not meet the minimum (or maximum) output performance of the smallest (or biggest)
43 load profile, as defined in Table 4.
44 NOTE 2 This standard does not specify performance or safety requirements. For safety requirements see EN 60335-1 in
45 conjunction with EN 60335-2-21.
46 2 Normative references
47 The following documents, in whole or in part, are normatively referenced in this document and are
48 indispensable for its application. For dated references, only the edition cited applies. For undated
49 references, the latest edition of the referenced document (including any amendments) applies.
50 EN 60379 Methods for measuring the performance of electric storage water-heaters for household
51 purposes
52 3 Terms and definitions
53 For the purposes of this document, the following terms and definitions apply.
54 3.1
55 storage water heater
56 water heater that uses electric heating elements as the means of heating water for long-term storage
57 in a thermally insulated container and provided with a device to control the water temperature
58 3.2
59 primary function
60 to heat water for the production of hot water for household and similar needs
61 3.3
62 energized storage water heater
63 storage water heater that is designed to supply hot water and energised for 24h per day
64 3.4
65 off-peak storage water heater
66 storage water heater that is designed to supply hot water whilst only being supplied with electrical
67 energy at off-peak/low tariff periods
68 Note 1 to entry: The off-peak storage water heater is required to fulfil the requirements of the tapping pattern between 7:00h
69 and 22:00h without external energy supply, e.g. to enable operation at off-peak/low-tariff periods and/or to operate in conditions
70 of insecurity of energy supply. A product qualifies as “off-peak” if it is only energized for a maximum of 8 consecutive hours
71 anywhere between 22:00h and 7:00h during the test with the 24h tapping pattern.

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72 3.5
73 load profile
74 means the output performance (in terms of flow-rates, temperatures, tapping pattern, etc.) of a storage
75 water heater when fulfilling its primary function under specific ambient conditions (see Tables 3 and 4),
76 as declared by the manufacturer
77 3.6
78 energy efficiency
79 means the ratio between the delivered energy in the sanitary hot water for its load profile and the
80 consumed electrical energy
81 3.7
82 storage volume
83 rated quantity of water stored in the appliance
84 Note 1 to entry: This is declared in litres.
85 3.8
86 smart control
87 device that automatically adapts the water heating process to individual usage conditions with the aim
88 of reducing energy consumption
89 4 Symbols and Units
90 Table 1 – Symbols
Unit Description
Symbol
[%] Energy efficiency of a storage water heater.
η
elecwh
Q [kWh] Delivered energy for the 24h tapping pattern for the load profile of the water
ref
heater.

Q [kWh] Electricity consumption with the relevant 24h tapping pattern.
elec
[°C]
θ´ mean water temperature for the determination of θ , measured at the outlet
p p
f [l/min] Minimum flow rate to be reached during tapping.
T [°C] Temperature at which hot water starts contributing to reference energy that’s
m
to say temperature from which counting of useful energy content starts.
T [°C] Minimum (peak) temperature to be achieved during tapping.
p
Q [kWh] Electricity consumption over 24h test (step 4).
testelec
Q Sum of energy contents of n draw-off.
[kWh]
H2O
full−drawing
Sum of quantity of hot water totally delivered during the tapping period.
[litres]
V
water
V [litres] Measured volume delivered at the mean water temperature.
40_exp
o
V Mixed water quantity delivered at 40 C.
[litres]
40
C [litres] Actual capacity of Water Heater
act
m [kg] Actual weight of water contained inside the tank of the Water Heater
act
smart Presence or not of smart control (value shall be 0 or 1).
SCF Efficiency gain by smart control function.
91

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92 5 Calculation of the electrical energy efficiency (η )
elecwh
93 The electrical energy efficiency (η ) of a storage water heater is the ratio between the delivered
elecwh
94 energy in the hot water for the tapping pattern of its load profile and the consumed energy. The
95 consumed energy is the result of the test of the water heater with adjustments for:
96 − smart control that can reduce the energy consumption;
97
98 The electrical energy efficiency of a storage water heater shall be calculated as (Equation 1):
Q
ref
η =
99 (Eq. 1)
elecwh
Q (1−SCF⋅smart)
elec
100 where:
101 − Q is the delivered energy for the 24 h tapping pattern for the load profile of the water heater, in
ref
102 kWh;
103 − Q is the consumption of electric energy with the relevant 24h tapping pattern, in kWh;
elec
104 − smart indicates the presence of smart control and is yes = 1, no = 0;
105 NOTE SCF=0 in case no smart control is detected during testing (9.2).
106 For electric storage water heaters the declared electric energy efficiency shall be:
107 (Eq. 2)  η ≤ 100%
elecwh
108 which is a necessary condition to apply because the formula (Eq. 1) could give a higher efficiency for
109 electric storage water heaters with smart control.
110 6 Measured parameters
111 The parameters below shall be established following the measurement methods described in following
112 Paragraph 7 and 9:
113 a) Electricity consumption [kWh/d];
114 b) Electrical energy efficiency [%];
115 c) Storage volume [litre].
116 7 General conditions for measurements
117 Measurements shall be carried out with a supply of:
118 Table 2 – Electricity
Permissible
Uncertainty of
deviation
Measured quantity Unit Value measurement Notes
(average over
(accuracy)
test period)
Electricity
Power W  ± 2 %
energy kWh  ± 2 %
voltage, test-period > 48 h V 230/ 400 ± 4 % ± 0,5 %
voltage, test-period < 48h V 230/ 400  ± 2 % ± 0,5 %
electric current A  ± 0,5 %
frequency Hz 50 ± 1 %

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119
120 The next table gives additional test conditions and tolerances for test outputs (i.e. thermal energy).
Table 3 – Test conditions and outputs. Set values and tolerances
Permissible
Permissible
deviations Uncertainty
deviation
of of
Measured quantity Unit Value (average Notes
individual measurement
over test
measured (accuracy)
period)
values
Time
Time s  ± 0,1 s
Maximum sample rate (during the
s 3 s   ± 0,2 %
deliver of hot water)
Maximum sample rate (during the
s 60 s  ± 0,2 %
no-deliver of hot water)
Sanitary water
cold water temperature °C/ K 10 °C ± 2 K ± 2 K ± 1 K

cold water pressure MPa 0.3 MPa  ± 5 %

a,b
hot water temperature °C/ K pattern  ± 1 K
volume flowrate l / min pattern  ± 1 %
volume measurements l   ± 0,5 %
± 2 % ± 2 % ± 2 %
c
thermal energy kWh pattern
(overall) (or ±10Wh) (or ±10Wh)
Ambient air
Temperature °C/ K 20 °C ± 2 K  ± 1 K
a To be measured by "rapid response thermometer", meaning an instrument that registers within 1 s. at least 90% of the final
temperature rise from 15 to 100 °C when the sensor is plunged in still water.
b Thermocouple with a maximum diameter of 0,5mm, centred in stream, directly at outlet
c Apart from the maximum deviation a correction factor Qref/QH2O is applied, whereby Qref is taken from Table 4 and QH2O
is the energy content of the useful water actually delivered during the test. "Useful water" is water with a temperature higher
than a threshold value Tm for tappings in a profile specified in Table 4.
121
122 All other installation requirements are made according to the manufacturer’s instructions.
123 8 Reference Conditions
124 Table 4 specifies the tapping patterns for the chosen Load Profile. Parameters in the Table are:
125 a. Load Profile [XXS-4XL, in header row of table];
126 b. h hour [hh:mm] starting at 0:00 h;
127 c. Q [kWh] useful energy content of water withdrawal to be achieved in the draw-off;
tap
128 d. f [l/min] minimum flow rate to be reached during tapping;
129 e. T [°C] temperature from which counting of useful energy content starts;
m
130 f. T [°C] minimum (peak) temperature to be achieved during tapping;
p
131 g. Q [kWh/d] daily (24h) useful energy content of all water draw-offs, effectively the sum of all
ref
132 Q .
tap
133
134 For all tests a cold water temperature of 10 ± 2 ºC shall be used.
135 As much as possible, the test method uses a ‘black-box’ approach, i.e. largely technology
136 independent. This means amongst others that the laboratory uses the original appliance thermostat, in
137 the position specified by manufacturer, and at the factory settings. If the product requires manual
138 thermostat operation to obtain the temperatures in Table 4, this shall be done during the test.

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139 Table 4 – Water heater load patterns (reference test tapping patterns)
XXS XS S  M L XL  XXL 3XL 4XL
Qtap f Tm Tp Qtap f Tm Tp Qtap f Tm Tp  Qtap f Tm Tp Qtap f Tm Tp Qtap f Tm Tp  Qtap f Tm Tp Qtap f Tm Tp Qtap f Tm Tp
l/mi l/mi
h h
h kWh ºC ºC kWh l/min ºC ºC kWh l/min ºC ºC kWh l/min ºC ºC kWh l/min ºC ºC kWh l/min ºC ºC kWh l/min ºC ºC kWh l/min ºC ºC kWh ºC ºC
n n
07.00 0, 105 2 25   0,105 3 25  07.00 0,105 3 25 0,105 3 25 0,105 3 25  07.00 0,105 3 25 11,2 48 40  22,4 96 40
07.05        07.05 1,400 6 40 1,400 6 40    07.05
      1,820 1,820
07.15   07.15    6 40  07.15 6 40
07.26       07.26     0,105 3 25  07.26 0,105 3 25
07.30 0, 105 2 25 0,525 3 35 - 0,105 3 25  07.30 0,105 3 25 0,105 3 25    07.30
07.45       07.45   0,105 3 25 4,420 10 10 40 07.45 6,240 16 10 40
08.01        08.01 0,105 3 25   0,105 3 25  08.01 0,105 3 25 5,04 24 25  10,08 48 25
08.05       08.05   3,605 10 10 40   08.05
08.15       08.15 0,105 3 25   0,105 3 25  08.15 0,105 3 25
08.25       08.25   0,105 3 25    08.25
08.30 0, 105 2 25   0,105 3 25  08.30 0,105 3 25 0,105 3 25 0,105 3 25  08.30 0,105 3 25
08.45       08.45 0,105 3 25 0,105 3 25 0,105 3 25  08.45 0,105 3 25
09.00       09.00 0,105 3 25 0,105 3 25 0,105 3 25  09.00 0,105 3 25 1,68 24 25  3,36 48 25
0,105 0,105 0,105 0,105 0,105 0,105
09.30 2 25   3 25  09.30 3 25 3 25 3 25  09.30 3 25
10.00       10.00     0,105 3 25  10.00 0,105 3 25
10.30       10.30 0,105 3 10 40 0,105 3 10 40 0,105 3 10 40 10.30 0,105 3 10 40 0,84 24 10 40 1,68 48 10 40
11.00       11.00     0,105 3 25  11.00 0,105 3 25
11.30 0, 105 2 25   0,105 3 25  11.30 0,105 3 25 0,105 3 25 0,105 3 25  11.30 0,105 3 25
11.45 0, 105 2 25   0,105 3 25  11.45 0,105 3 25 0,105 3 25 0,105 3 25  11.45 0,105 3 25 1,68 24 25  3,36 48 25
0,105
12.00 2 25     12.00      12.00
12.30 0, 105 2 25      12.30       12.30
12.45 0,105 2 25 0,525 3 35 - 0,315 4 10 55 12.45 0,315 4 10 55 0,315 4 10 55 0,735 4 10 55 12.45 0,735 4 10 55 2,52 32 10 55 5,04 64 10 55
14.30       14.30 0,105 3 25 0,105 3 25 0,105 3 25  14.30 0,105 3 25
15.00       15.00     0,105 3 25  15.00 0,105 3 25
15.30        15.30 0,105 3 25 0,105 3 25 0,105 3 25  15.30 0,105 3 25 2,52 24 25  5,04 48 25
16.00       16.00     0,105 3 25  16.00 0,105 3 25
16.30        16.30 0,105 3 25 0,105 3 25 0,105 3 25  16.30 0,105 3 25
17.00       17.00     0,105 3 25  17.00 0,105 3 25
18.00 0, 105 2 25   0,105 3 25  18.00 0,105 3 25 0,105 3 25 0,105 3 25  18.00 0,105 3 25
18.15 0, 105 2 25   0,105 3 40  18.15 0,105 3 40 0,105 3 40 0,105 3 40  18.15 0,105 3 40
18.30 0, 105 2 25      18.30 0,105 3 40 0,105 3 40 0,105 3 40  18.30 0,105 3 40 3,36 24 25  6,72 48 25
19.00 0, 105 2 25      19.00 0,105 3 25 0,105 3 25 0,105 3 25  19.00 0,105 3 25
19.30 0, 105 2 25      19.30       19.30
20.00 0, 105 2 25      20.00       20.00
20.30   1,050 3 35 - 0,420 4 10 55 20.30 0,735 4 10 55 0,735 4 10 55 0,735 4 10 55 20.30 0,735 4 10 55 5,88 32 10 55 11,76 64 10 55
20.45 0, 105 2 25      20.45       20.45
   4,420 6,240
20.46      20.46    10 10 40 20.46 16 10 40
21.00 0, 105 2 25      21.00   3,605 10 10 40   21.00
21.15 0, 105 2 25      21.15 0,105 3 25   0,105 3 25  21.15 0,105 3 25
 0,525 1,400 0,105 4,420 6,240 12,04 24,08
21.30    5 45  21.30 6 40 3 25 10 10 40 21.30 16 10 40 48 40  96 40
21.35 0,105 2 25      21.35       21.35
21.45 0, 105 2 25      21.45       21.45
2,100 2,100 2,100 5,845 11,655 19,070 24,530 46,760 93,520
Qref      Qref     Qref

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140 9 Test procedures
141 9.1 Standard Test Procedure
142 9.1.1 Introduction
143 The following paragraphs describe the test procedure to establish the electricity consumption Q
elec
144 during a 24h test.
145 9.1.2 Installation
146 Install product in test environment according to manufacturer’s instructions. Designated floor-standing
147 appliances are to be placed on a floor with low thermal leakage (e.g. 20mm thick medium density
148 fibreboard could be placed under the test object at a distance of 100mm above the floor of the test
149 room).
150 Wall-mounted products shall be mounted on a panel at least 150 mm from any structural wall with a
151 free space of at least 250 mm above and below the product and at least 700 mm to the sides.
152 Products designated to be built-in shall be mounted according to manufacturer’s instructions.
153 Products with declared Load Profiles 3XL and/or 4XL may be tested on-site, provided test conditions
154 are equivalent, possibly with correction factors, to the ones referenced here.
155
156
Position of the thermocouples for
Vertical and Horizontal models (   ).
157
158
159
160
161
162
Thermocouple or
5 cm
probe position for
163
reference thermostat
h/2
h
164
165
166
167 Circular
Position of thermocouple
welding
or reference probe for
reference thermostat
168
b) For horizontal water heater
169
For the horizontal devices, the reference temperature is probed on
the higher generator of the tank, at 5 cm of the circular welding on
170
the cylindrical part and opposed to the heater.
a) For vertical water heater
171 Figure 1 – Position of the thermocouples for Vertical and Horizontal models

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172
173 Key
174 1 thermocouple outlet temperature
175 2 thermocouple cold water temperature
176 3 measurement flow rate 4: valve bypass
177 5 safety valve
178 6 valve tapping
179 NOTE Distance between the cold water inlet of the water heater and the position of the thermocouple measuring cold water
180 shall be lower or equal to 100mm.
181 Figure 2 – hydraulic connection (unvented products)
182 9.1.3 Stabilisation
183 Keep product at ambient conditions (test room) until all parts of the product have reached ambient
184 conditions ± 5 K (at least 24h for storage type products).

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Figure 3 – Test procedure Figure 4 – Test procedure
for “ENERGIZED APPLIANCES” for “OFF-PEAK APPLIANCES”
185 9.1.4 Storage volume
186 STEP 0 of Figures 3 and 4: the volume of the tank in a storage electric water heater is measured as
187 follows.
188 The empty water heater is to be weighted; the weight of taps on inlet and/or outlet pipes shall be
189 considered.
190 Then the storage water heater is filled with cold water in accordance with the manufacturer’s
191 instruction at cold water pressure. The water supply is then cut off.
192 The filled water heater is to be weighted.
193 The difference of the two weights (m ) is to be converted into the volume in litres.
act
m
act
194 (Eq. 3) C = [l]
act
0.9997
195 This volume is to be reported in litres to the nearest one-tenth litres. The measured value (actual
196 value) shall not be more than 2% lower than the rated value.
197 9.1.5 Filling and heat-up
198 STEP 1 of Figures 3 and 4: products with storage-facilities shall be filled with cold water (10 ± 2 °C);
199 Filling stops at the applicable cold water pressure (see Table 4).
200 STEP 2 of Figures 3 and 4: the product is energized to reach “out-of-the-box” factory settings, e.g. for
201 storage temperature. The product’s own means of control (thermostat) shall be used. The next stage
202 starts at thermostat cut out.

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oSIST prEN 50440:2014
prEN 50440:2014 - 12 -

203 9.1.6 Stabilisation at zero-load
204 STEP 3 of Figures 3 and 4: keep the product at normal operating conditions as specified by the
205 manufacturer without draw-offs during at least 12 h. This stage ends - and next stage starts - at the
206 first thermostat cut-out after 12h.
207 9.1.7 Tapping
208 STEP 4 of Figures 3 and 4: for the selected Load Profile, draw-offs are made in accordance with the
209 specifications of the appropriate 24h tapping pattern in Table 4. Tapping pattern starts directly after
210 thermostat cut out from stabilisation part with the first tapping at 7:00h time-value as implied in Table
211 4. The tapping period ends 24h later. The required useful energy content of the hot water is the total
212 Qref [in kWh] in Table 4.
213 During the tapping stage technical parameters (power, temperature, etc.) are established in
214 accordance with specifications in Table 4. During draw-offs the recommended maximum sample rate
215 is 3s (see Table 3). Recorded values shall be part of the technical test report.
216 Electricity consumption over the 24h test Qtestelec [kWh electricity] will be measured over 24h (i.e. t -
5
217 t ).
3
218 Useful energy content of the hot water drawn-off QH2O [kWh] is determined as described below:
219 • follows from average in-/outlet temperature difference during the useful tapping period in [K],
-3
220 the tapped useful water volume in litre. and the specific heat of water cw (1,163x10 kWh/(litre
221 x K)):
222
223 (Eq. 4) Q [i]=∆T[i]×V[i]×c
H 2O w
224
225 where:
226
227 • QH2O[i] is the "Energy content" of one draw-off in [kWh];
228 • ΔT[i] is the average in-/outlet temperature difference during the useful tapping period in [K];
229 • V[i] is the tapped useful water volume [litres];
-3
230 • cw (1,163x10 kWh/(litre x K)) is the specific heat of water.
231
232
233 For all the n draw-offs of one tapping profile the energy content is the sum:
234
235 (Eq. 5) Q = Q [i] for i= 1to n
H 2O ∑ H 2O
236
237 This formula can have many formats, e.g. more dynamic formats using flowrate and instantaneous
238 temperature differences, but it comes down to the same result.
239 Products to be classified as “Off-peak” appliances shall be energized for a maximum period of 8
240 consecutive hours (t -t ) during 22:00h and 7:00h of the 24h tapping pattern as specified in Table 4.
5 4
full−drawing
241 In addition V [litres] will be recorded; it is the sum of quantity of hot water totally delivered
water
242 during the tapping period.
243 9.1.8 Reporting of Qelec
244 Qtestelec shall be corrected for any energy surplus or deficit outside the strict 24h tapping period, i.e.
245 a possible energy difference before and after the tapping cycle is taken into account. Furthermore, any
246 surplus or deficit in the delivered useful energy content of the hot water is taken into account in the
247 following equations for Qelec.

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oSIST prEN 50440:2014
- 13 - prEN 50440:2014

Q
  1,163×C ×(T(t )−T(t ))
 
ref
act 3 3 5 5
248 (Eq. 6) Q = × Q + [kWh]
elec  testelec 
 
Q 1000
 
 H 2O
249 where T and T are water temperatures measured at the dome of water heater, respectively at t and
3 5 3
250 t .
5
251 9.1.9 Re-stabilisation at zero-load
252 STEP 5 of Figures 3 and 4: keep product at nominal operating conditions without draw-offs during at
253 least 12 h. For products with storage-facilities subject to a control cycle this stage ends at the first
254 thermostat cut-out after 12h.
255 9.1.10 Mixed water quantity delivered at 40 °C
256 STEP 6 of Figures 3 and 4: quantity of water at 40 °C, which has the same heat content (enthalpy) as
257 the hot water which is delivered above 40 °C at the output of the water heater.
258 Immediately following measurement according to “Re-stabilization at zero-load” (STEP 5), the water
259 heater is switched off after the last cut-out of the thermostat.
260 Then a quantity of water equal to the rated capacity is withdrawn through the outlet at a constant rate
261 of flow by supplying cold water; the flow of water from open outlet water-heaters is controlled by the
262 inlet valve. The flow in any other type of water-heaters is kept constant by means of a valve fitted in
263 the outlet or the inlet.
264 The rate of flow is adjusted to the maximum value showed on “Water heater load pattern” chosen to
265 perform the appliance during the tapping cycle.
266
267 T [°C] is the water temperature, without withdrawal of water, measured with a thermocouple placed
set
268 inside the upper section of the tank. For metal tanks the thermocouple may be placed on the outer
269 surface of the ta
...

SLOVENSKI oSIST prEN 50440:2005

PREDSTANDARD
november 2005
Učinkovitost gospodinjskih električnih akumulacijskih grelnikov vode
Efficiency of domestic electrical storage water heaters
ICS 91.140.65 Referenčna številka
oSIST prEN 50440:2005(en)
©  Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

---------------------- Page: 1 ----------------------
DRAFT
EUROPEAN STANDARD prEN 50440
NORME EUROPÉENNE
EUROPÄISCHE NORM August 2005

ICS Will supersede EN 60379:2004


English version


Efficiency of domestic electrical storage water-heaters


Efficacité des chauffe-eau électriques à Wirkungsgrad von elektrischen
accumulation Warmwasserspeichern für den
Hausgebrauch


This draft European Standard is submitted to CENELEC members for CENELEC enquiry.
Deadline for CENELEC: 2006-02-24

It has been drawn up by Technical Committee CENELEC TC 59X.

If this draft becomes a European Standard, CENELEC members are bound to comply with the
CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the
status of a national standard without any alteration.

This draft European Standard was established by CENELEC in three official versions (English, French,
German). A version in any other language made by translation under the responsibility of a CENELEC
member into its own language and notified to the Central Secretariat has the same status as the official
versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden,
Switzerland and United Kingdom.

Warning : This document is not a European Standard. It is distributed for review and comments. It is
subject to change without notice and shall not be referred to as a European Standard.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels


© 2005 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Project: 16330 Ref. No. prEN 50440:2005 E
Draft for Enquiry

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prEN 50440:2005 – 2 –
Foreword
This draft European Standard was prepared by the Technical Committee CENELEC TC 59X, Consumer
information related to household electrical appliances. It is submitted to the CENELEC enquiry.
This European Standard will supersede EN 60379:2004, Methods for measuring the performance of electric
storage water-heaters for household purposes.
__________

Draft for Enquiry

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– 3 – prEN 50440:2005
Content
1 Scope .4
2 Normative references .4
3 Symbols and definitions .4
3.1 Symbols. 4
3.2 Definitions. 5
4 Appliances categories.6
5 List of measurements.6
6 General conditions for measurements .6
7 Preparation of the storage water-heater.7
7.1 Mounting of the storage water-heater. 7
7.2 Reference thermostat. 7
8 Methods of measurement .8
8.1 Measurement of the actual capacity: C . 8
act
8.2 Energy consumption relevant to usage . 8
9 Control procedure.15
Annex A (normative) Daily tapping pattern I - 36 liters at 60 °C.19
Annex B (normative) Daily tapping pattern II - 100 liters at 60 °C.20
Annex C (normative) Daily tapping pattern III - 200 liters at 60 °C.21
Annex D (informative) Calculation method.22

Figures
Figure 1 – Position of the thermocouple of the reference thermostat .16
Figure 2 – Testing sequence for water-heaters with a rated capacity < 45 l . 17
Figure 3 – Testing sequence for storage water-heaters with a rated capacity ≥ 45 l. 18
Figure D.1 – Evolution of the relative surface dedicated to heat transfer .23

Tables
Table 1 – Results for water-heater with rated capacity < 45 l . 11
Table 2 – Tapping profile depending on the rated capacity . 12
Table 3 – Results for water-heater with a rated capacity ≥ 45 l . 15
Table D.1 – Calculation results. 24

Draft for Enquiry

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prEN 50440:2005 – 4 –
1 Scope
This European Standard applies to thermally insulated domestic storage water-heaters with 5 l or more of
rated capacity.
The purpose of this European Standard is to define the methods to be used for measuring energy
consumption of thermally insulated domestic electric storage water-heaters taking into account the efficiency
of the appliance related to standing loss and the energy consumption when withdrawing standardized
quantities of water. This European Standard is concerned neither with safety nor with performance
requirements.
2 Normative references
No normative references are given.
3 Symbols and definitions
3.1 Symbols


Water flow during draw-off cycles
[l/min]
v
η  Performance ratio of the appliance

[°C] Temperature indicated on thermostat dial
θ

[°C] Water temperature after reference thermostat cut-in (as measured
θ
in
with the thermocouple reference)
[°C] Mean water temperature after reference thermostat cut-in (as
θ
in M
measured with the thermocouple reference)
[°C] Mean water temperature without withdrawal
θ
M
[°C] Water temperature after reference thermostat cut-out (as
θ
out
measured with the thermocouple reference)
[°C] Mean water temperature after reference thermostat cut-out (as
θ
out M
measured with the thermocouple reference)
[°C]
θ´ Mean water temperature for the determination of θ , measured at
p p
the outlet
[°C] Hot water temperature before beginning of the draw-off cycle
θ
AA
(testing procedure 2)
θ [°C] Temperature of the water inside of the water-heater after the first
AH
cut out of the thermostat
[°C] Ambient temperature during the tests
θ
amb
[°C] Temperature of inlet cold water
θ
C
[°C] Mean water temperature at the outlet
θ
p
[°C] Water temperature during measurement, measured at the outlet
θ
S
A [°C] or [K] Deviation of dial calibration
C [ l ] Actual capacity
act
C [ l ] Rated capacity
R
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– 5 – prEN 50440:2005
E [kWh/24 h] Energy consumption per 24 h
E [kWh] Measured value of standing loss
1
E [kWh] Calculated energy consumption for a 8 hours period when
2
maintaining hot conditions with test conditions [kWh]
E [kWh] Calculated corrected energy E according to required design
3 2
temperature for test.
E [kWh] Corrected energy consumption during test according to tapping
ab
cycle n° [1, 3]
E [kWh] Energy added to the water-heater by reheating after the water
HEAT
withdrawal  [kWh]
E [kWh] Corrected E according to required design temperature
HEAT corr HEAT
E [kWh] Measured energy consumption when maintaining water-heater in
v
hot conditions after heating up (8.2.1.4)
E [kWh] Measured energy consumption during 24 h cycle for small
v_small
appliances (8.2.1.4)
E [kWh] Thermal energy withdrawn during 24 h cycle
WATER
Q [kWh/24 h] Standing loss per 24 h and temperature difference 45 °C
pr
Q [kWh] Standing loss per 24 h, calculated from E
pr_cal 1
t [s] Measurement time
t [s] Time to fill the water-heater
0
t [s] Start up measurement time of heating (Step 2)
1
t [s] Start-up measurement time of Step 3
2
t [s] Start-up measurement time of Step 4
3
t [s] Start-up measurement time of Step 5
4
t [s] Start-up measurement time of Step 6
5
t [s] Start-up measurement time of Step 7
6
t [s] Start-up measurement time of Step 8
7
t [s] Correction value for heating up duration according to experimental
h
data
t [s] Measured duration for heating up
h_exp
t [s] Reheating-time
R
V [ l ]
40_exp Measured volume delivered at a mean water temperature of θ
p
V
[ l ] Mixed water quantity delivered at 40 °C
40
W
[ l ] Quantity of water used during the 24 h cycle
u
(8.2.1.4.2 or 8.2.2.4.2)

3.2 Definitions
3.2.1
storage water-heater
appliance intended for heating water in a thermally insulated container, for the long-term storage of heated
water and provided with a device to control the water temperature
Draft for Enquiry

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prEN 50440:2005 – 6 –
3.2.2
rated capacity (C )
R
water capacity assigned to the water-heater by the manufacturer and marked on it
3.2.3
actual capacity (C )
act
water capacity determined by measurement
3.2.4
standing loss per 24 h (Q )
PR
energy consumption of a filled water-heater, when connected to the electrical supply, after steady state
conditions have been reached, during any 24 h period when no water is withdrawn
3.2.5
mixed water quantity delivered at 40 °C (V )
40
quantity of water at 40 °C which has the same heat content (enthalpy) as the content of the storage water-
heater at a water temperature of 65 °C
3.2.6
reference thermostat
device used to increase precision of the measurement of stand-by loss
4 Appliances categories
Category 1: Rated capacity from 5 l to < 45 l
Category 2: Rated capacity of 45 l or more than 45 l
5 List of measurements
• measurement of the actual capacity C
act
• standing loss per 24 h Q
pr
• mixed water output V
40
• electric consumption relevant to the usage E
HEAT corr
• energy loss per cycle E
3
• duration for heating up [s] t
h_exp
• water used during the 24 h cycle W
u
6 General conditions for measurements
Unless otherwise specified measurements are carried out on the water-heater operating
• in a substantially draught-free room,
• at an ambient temperature θ = (20 ± 2) °C.
amb
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– 7 – prEN 50440:2005
The ambient temperature is calculated from measurements at a number of locations half-way between the
water-heater and the walls of the room or 1 m distant from the water-heater, whichever is less, and at half
the height of the water-heater.
Measurements shall be carried out with a supply voltage of 230/400 V ± 2 %.
The water is supplied at a temperature θ = (15 ± 2) °C and provided from a source having a substantially
C
steady pressure.
All other installation requirements are made according to the manufacturer’s instructions.
7 Preparation of the storage water-heater
7.1 Mounting of the storage water-heater
Wall-mounted water-heaters are mounted on a panel situated at least 150 mm from any structural wall.
There shall be a clear space of at least 250 mm above and below the heater and at least 700 mm at the
sides and front.
Floor-mounted water-heaters are placed on the floor or on any stand supplied with them. A false floor may
be used to facilitate measurements.
Water-heaters for building-in are built in according to the manufacturer's instructions.
The water-heater is connected to the water system by means of a pressure hose.
7.2 Reference thermostat
7.2.1 Role of reference thermostat
The role of this device is to manage the repetition of the course of the heating cycles in order to ensure their
stability. The substitution of the original thermostat by this device makes it possible to become free from the
random behaviour of the thermostat which often significantly influences the results of the test.
7.2.2 Properties of reference thermostat
7.2.2.1 Function of reference thermostat
To ensure the switching on- and off-level of the heater.
7.2.2.2 Position of reference thermostat
The position of the temperature probe of the reference thermostat is indicated in Figure 1.
7.2.2.3 Tests where the reference thermostat is used
For standing loss per 24 h (Q ) see 8.2.1.5 and 8.2.2.7.
pr
For hot water output and mixed water output (V ) see 8.2.1.6 and 8.2.2.8.
40
Draft for Enquiry

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prEN 50440:2005 – 8 –
7.2.2.4 Reference thermostat characteristics
The characteristics of the reference thermostat are as follows:
– switch-on at a reference temperature of 65 °C -0/+1 °C;
– switch-off at a reference temperature of 60 °C -0/+1 °C.
7.2.2.5 Application of reference thermostat
The device may be carried out with various techniques. For instance the reference thermocouple, already
used for the measurement of the heating thresholds of release and interlocking (Figure 1), can be associated
with software designed to detect these thresholds in order to manage the heating periods.
8 Methods of measurement
8.1 Measurement of the actual capacity: C
act
The water-heater is disconnected from the water mains.
The water-heater is filled in accordance with the manufacturer’s instructions. It is then emptied through the
water inlet or – if not possible – through the drain plug opening. Alternatively the actual capacity can be
calculated from the difference of weights of the empty and the filled appliance.
For measurements of capacity water from separate feed cisterns is not taken into account. The actual
capacity measured is recorded as C to the nearest one-tenth litre and shall not be less than the rated
act
capacity C as stated by the manufacturer.
R
8.2 Energy consumption relevant to usage
8.2.1 Water-heaters with a rated capacity < 45 l (testing sequence see Figure 2)
8.2.1.1 Step 1: Filling
Water-heater is filled with water of a temperature of 15 ± 2 °C.
The time to fill the water-heater t is recorded.
0
8.2.1.2 Step 2: Heating up
t : time the water-heater is powered ON (t - t ) < 15 min
1 1 0
t : time when the thermostat cuts off the first time
2
Result of Step 2 : heating up time t
h
Initial temperature of the water inside of the water-heater: θ [°C]
C
[°C]
Water temperature at the first cut out of the thermostat: θ
AH
Heating up time: t = t – t
h_exp 2 1
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– 9 – prEN 50440:2005
t is calculated with Equation (1):
h
65 − 15
t = ⋅ (t ) (1)
h h_exp
Θ − Θ
AH C
8.2.1.3 Step 3: Stabilisation of the system
The system remains energised for at least 12 h to stabilise the temperature (t – t > 12 h).
3 2
t : time when the thermostat cuts off the first time after 12 hours.
3
Thermostat settings: thermostat cut off θ = (65 -0/+1 °C)
out M
The difference between thermostat cut in and thermostat cut off shall be lower than 5 K.
8.2.1.4 Step 4: Withdrawal of water
8.2.1.4.1 Choice of tapping profile
The tapping cycle used is determined according to Annex A.
The appliance remains energised during Step 4.
8.2.1.4.2 Withdrawal of water and 24-h-cycle as given in Figure 2
t : time when the tapping cycle starts (corresponds to 07:00 according to the tables of daily profile in
3
Annex A).
Flow rate for rated capacities of < 10 l: 2 l/min
Flow rate for rated capacities of 10 to < 45 l: 5 l/min
Results: Thermal energy withdrawn: E  [kWh]
WATER
Energy consumption: E  [kWh]
v_small
n
 
− 5
 
E = 1,9184 ⋅10 ⋅ν& θ -θ ⋅ t − t (2)
∑    
WATER
i i ()i -1
Ci  
 Si 
i = 1
This procedure stops when the thermostat cuts off after at least 24 h from starting with Step 4 (t - t ≥ 24 h).
6 3
The energy E corresponds to the electrical energy consumption of the water-heater between times t
v_small 5
and t as the sum of E and of the energy necessary to reheat the appliance and maintain it in hot
3 WATER
condition.
A calculation is necessary to adapt (E – E ) to duration of 24 h and to the design temperature
v  small WATER
(output: 65 °C / input: 15 °C).
The figure (E – E ) corresponds to the energy consumption and shall be corrected to E for
V _small WATER HEAT
duration of 24 h according Equation (3):
 
24
E =()E −E ×  (3)
HEAT V_small WATER
 
t −t
 5 3 
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prEN 50440:2005 – 10 –
The thermostat cut-off temperatures at the beginning of the testing periods draw-off cycle and heat loss in
daily cycle (θ respectively θ ) shall be compared with the finishing θ respectively θ and corrected
AA out 1 out 1 out n
accordingly and the temperature difference between θ and θ shall be adjusted to 45 K.
amb M
The adjustment shall be done with the following Equations (4) and (5):
1,16×C × (Θ − Θ )
act out n out 1A
E =E + (4)
HEAT corr HEAT
1000
Result of Step 4: Energy needed to maintain the water-heater in hot condition E [kWh] and water used
ab
during the test W [ l ].
u
45
E =
...

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