CEN/TS 12977-2:2010

SLOVENSKI STANDARD
01-september-2010
1DGRPHãþD
SIST ENV 12977-2:2002
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Thermal solar systems and components - Custom built systems - Part 2: Test methods
for solar water heaters and combisystems
Thermische Solaranlagen und ihre Bauteile - Kundenspezifisch gefertigte Anlagen - Teil
2: Prüfverfahren
Installations solaires thermiques et leurs composants - Installations personnalisées -
Partie 2: Méthodes d'essai pour chauffe-eau solaires et installations mixtes
Ta slovenski standard je istoveten z: CEN/TS 12977-2:2010
ICS:
27.160 6RQþQDHQHUJLMD Solar energy engineering
91.140.10 Sistemi centralnega Central heating systems
ogrevanja
91.140.65 Oprema za ogrevanje vode Water heating equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL SPECIFICATION
CEN/TS 12977-2
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
April 2010
ICS 27.160 Supersedes ENV 12977-2:2001
English Version
Thermal solar systems and components - Custom built systems
- Part 2: Test methods for solar water heaters and
combisystems
Installations solaires thermiques et leurs composants - Thermische Solaranlagen und ihre Bauteile -
Installations personnalisées - Partie 2: Méthodes d'essai Kundenspezifisch gefertigte Anlagen - Teil 2: Prüfverfahren
pour chauffe-eau solaires et installations mixtes für Solaranlagen zur Trinkwassererwärmung und solare
Kombianlagen
This Technical Specification (CEN/TS) was approved by CEN on 9 September 2008 for provisional application.

The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their
comments, particularly on the question whether the CEN/TS can be converted into a European Standard.

CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available
promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS)
until the final decision about the possible conversion of the CEN/TS into an EN is reached.

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

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2010 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 12977-2:2010: E
worldwide for CEN national Members.

Contents Page
Foreword .5
Introduction .6
1 Scope .9
2 Normative references .9
3 Terms and definitions . 10
4 Symbols and abbreviations . 10
5 System classification . 12
6 Test methods . 12
6.1 General . 12
6.1.1 Suitability for drinking water . 12
6.1.2 Water contamination . 12
6.1.3 Freeze resistance . 13
6.1.4 High-temperature protection . 13
6.1.5 Reverse circulation prevention . 13
6.1.6 Pressure resistance . 13
6.1.7 Electrical safety. 13
6.2 Materials . 13
6.3 Components and pipework . 13
6.3.1 Collector and collector array . 13
6.3.2 Supporting frame . 14
6.3.3 Collector and other loops . 14
6.3.4 Circulation pump . 14
6.3.5 Expansion vessels . 14
6.3.6 Heat exchangers . 14
6.3.7 Store . 15
6.3.8 Pipework . 15
6.3.9 Thermal insulation . 15
6.3.10 Control equipment . 15
6.4 Safety equipment and indicators . 15
6.4.1 Safety valves . 15
6.4.2 Safety lines and expansion lines . 16
6.4.3 Blow-off lines . 16
6.4.4 Store shut-off valve . 16
6.4.5 Indicators . 16
6.5 Installation . 16
6.5.1 Roof tightness . 16
6.5.2 Lightning . 16
6.5.3 Snow and wind loads . 17
6.6 Initial operation, inspection and commissioning . 17
6.7 Documentation . 17
6.8 System performance (for small systems only) . 17
6.9 Water wastage (for small systems only) . 17
7 Optional performance test of small custom built solar heating systems . 17
7.1 General . 17
7.2 Test of the solar collector . 18
7.3 Test of the water store(s) . 18
7.4 Test of the control equipment . 19
7.5 Determination of the hot water comfort . 19
7.6 System simulation model . 19
7.7 Long-term performance prediction . 19
7.7.1 General . 19
7.7.2 Calculation procedure . 19
7.7.3 Prediction of yearly system performance indicators . 20
7.7.4 Calculation of the net auxiliary energy demand and fractional energy savings for
solar-plus-supplementary systems . 20
7.7.5 Calculation of the solar fraction for solar-only and preheat systems . 23
7.7.6 Calculation of the parasitic energy (for all system types) . 25
7.8 Presentation of performance indicators . 25
8 Performance test report . 26
Annex A (normative) Reference conditions for performance prediction . 28
A.1 General . 28
A.2 Pipe diameter and insulation thickness . 30
A.3 Calculation of mains water temperature at reference location . 30
A.4 Space heating heat load . 31
A.4.1 General . 31
A.4.2 Stockholm . 31
A.4.3 Davos . 32
A.4.4 Würzburg . 33
A.4.5 Athens . 35
Annex B (normative) Additional information regarding the calculation of the fractional energy
savings . 37
B.1 Definition of a conventional reference water heating system . 37
B.2 Calculation of fractional energy savings for other conditions . 37
Annex C (informative) Short-term system testing . 39
C.1 General . 39
C.2 Instrumentation, data acquisition and processing . 39
C.2.1 General . 39
C.2.2 Accuracy and calibration of sensors . 41
C.2.3 Data acquisition and processing . 41
C.3 Check of short-term system performance . 41
C.3.1 Principle. 41
C.3.2 Measurement of the system energy gain . 42
C.3.3 Criteria for termination of the test . 43
C.3.4 Simulation of the system useful energy gain using components data . 43
C.3.5 Comparison of measured with simulated data . 43
C.3.6 Test report . 44
C.4 Short-term test for long-term system performance prediction . 44
C.4.1 General . 44
C.4.2 Principle. 45
C.4.3 Measurements . 45
C.4.4 Criteria for termination of the test . 46
C.4.5 Identification of collector array parameters . 47
C.4.6 Criteria for the acceptance of the test results . 47
C.4.7 Test report . 49
C.4.8 Prediction of the yearly system gain . 49
Annex D (informative) Long-term monitoring . 51
D.1 General . 51
D.2 Evaluation chart . 52
D.3 Monitoring equipment . 52
D.4 Data analysis . 52
Annex E (informative) Determination of water wastage . 53
Bibliography . 54

Figures
Figure 1 — Energy balance for one store and two stores solar plus supplementary systems. 21
Figure 2 — Comparison of the gross auxiliary energy demand of the solar heating system, Q , to the
aux
gross energy demand of the conventional heating system, Q . 22
conv
Figure 3 — Energy balance for solar only systems . 24
Figure 4 — Energy balance for solar preheat systems . 25
Figure C.1 — Principle of the short term system performance check: Check and intercomparison of
useful energy gain . 41
Figure C.2 — Principle of the short term test and of the subsequent long term system performance
prediction . 45
Figure C.3 — Example of the predicted performance dependence on load level and irradiation for a
solar domestic hot water heating system (see [8]) . 50

Tables
Table 1 — Division for factory made and custom built solar heating systems . 7
Table 2 — Presentation of system performance indicators for solar-plus-supplementary systems . 26
Table 3 — Presentation of system performance indicators for solar-only and solar preheat systems . 26
Table A.1 — Reference conditions for performance presentation . 28
Table A.2 — External pipe diameter and insulation thickness for forced-circulation systems . 30
Table A.3 — Data for calculation of the mains water temperature at the reference locations . 31
Table A.4 — Space heating load file for Stockholm . 32
Table A.5 — Space heating load file for Davos . 33
Table A.6 — Space heating load file for Würzburg . 34
Table A.7 — Space heating load file for Athens – Example to be updated . 36
Table C.1 — Variables to be measured and corresponding maximum sampling intervals . 43
Table C.2 — Variables to be measured during system test, and corresponding maximum sampling
intervals . 45
Table C.3 — Range of variations of the driving variables to be scanned during a test outdoors . 47
Table C.4 — Permissible standard deviation for secondary collector parameters . 48

Foreword
This document (CEN/TS 12977-2:2010) has been prepared by Technical Committee CEN/TC 312 “Thermal
solar systems and components”, the secretariat of which is held by ELOT.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes ENV 12977-2:2001.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria, Croatia, Cyprus,
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia,
Spain, Sweden, Switzerland and the United Kingdom.
Introduction
a) Drinking water quality
In respect of potential adverse effects on the quality of water intended for human consumption caused by
the product covered by this document, it should be noted that:
1) this document provides no information as to whether the product may be used without restriction in
any of the Member States of the EU or EFTA;
2) while awaiting the adoption of verifiable European criteria, existing national regulations concerning
the use and/or the characteristics of this product remain in force.
b) Factory Made and Custom Built solar heating systems
EN 12976-1, EN 12976-2 and CEN/TS 12977-1 to -5 distinguish two categories of solar heating systems:
1) Factory Made solar heating systems; and
2) Custom Built solar heating systems.
The classification of a system as Factory Made or Custom Built is a choice of the final supplier, in
accordance to the following definitions:
3) Factory Made solar heating systems are batch products with one trade name, sold as complete and
ready to install kits, with fixed configurations. Systems of this category are considered as a single
product and assessed as a whole.
If a Factory Made Solar Heating System is modified by changing its configuration or by changing one
or more of its components, the modified system is considered as a new system. Requirements and
test methods for Factory Made solar heating systems are given in EN 12976-1 and EN 12976-2.
4) Custom Built solar heating systems are either uniquely built, or assembled by choosing from an
assortment of components. Systems of this category are regarded as a set of components. The
components are separately tested and test results are integrated to an assessment of the whole
system. Requirements for Custom Built solar heating systems are given in CEN/TS 12977-1, test
methods are specified in CEN/TS 12977-2 to -5. Custom Built solar heating systems are subdivided
into two categories:
i) Large Custom Built systems are uniquely designed for a specific situation. In general they are
designed by HVAC engineers, manufacturers or other experts;
ii) Small Custom Built systems offered by a company are described in a so-called assortment file,
in which all components and possible system configurations, marketed by the company, are
specified. Each possible combination of a system configuration with components from the
assortment is considered as one Custom Built system.
Table 1 shows the division for different system types.
Table 1 — Division for factory made and custom built solar heating systems
Factory Made solar heating systems Custom built solar heating systems
(EN 12976-1, -2) (CEN/TS 12977-1, -2, -4, -5 and EN 12977-3)
Integral collector-storage systems for domestic hot
Forced-circulation systems for hot water preparation
water preparation
and/or space heating/cooling, assembled using
components and configurations described in a
Thermosiphon systems for domestic hot water
documentation file (mostly small systems)
preparation
Uniquely designed and assembled systems for hot
Forced-circulation systems as batch product with
water preparation and/or space heating/cooling
fixed configuration for domestic hot water preparation
(mostly large systems)
NOTE 1 Forced circulation systems can be classified either as Factory Made or as Custom Built, depending on the
market approach chosen by the final supplier.
NOTE 2 Both Factory Made and Custom Built systems are performance tested under the same set of basic reference
conditions as specified in EN 12976-2:2006, Annex B and in CEN/TS 12977-2:2010, Annex A. In practice, the installation
conditions may differ from these reference conditions.
c) Test methods and procedures for the analysis of large custom built solar heating systems
Quality assurance is of primary importance for large custom built systems. The total investment cost for
such systems is higher than for smaller ones, although the specific investment cost (i.e., per m² collector
area) is lower. In several European countries, the potential of large custom built systems from the point of
view of conventional energy savings is much larger than for smaller ones. Moreover, the
return-on-investment is in many cases more favorable for large systems than for small ones. Hence, both
the purchasers of large custom built systems and the governments are interested in efficient, reliable and
durable systems, the thermal performance of which may be accurately predicted, checked and
supervised.
The test methods in this document provide a means of verifying the compliance of large custom built
systems with the requirements in CEN/TS 12977-1.
NOTE Within the framework of the EU ALTENER Programme the project "Guaranteed Solar Results" (GSR)
was addressing similar objectives in respect of quality assurance (see [7], [8]). Similar procedures and monitoring
equipment were used as described in Annexes C and D. It might be necessary to update Annexes C and D later on
in a revision of this document when more experience is available.
As large custom built systems are by definition unique systems, only general procedures on how to check
and supervise them may be given. An additional difficulty in the formulation of procedures is the fact that
they have to be adapted to the dimension of the large custom built system considered, which may vary
2 2
from typically 30 m to 30 000 m of collector area. Therefore, several possible levels of analysis are
included (Annexes C and D).
The objective of the two short-term system tests presented in Annex C is the characterization of system
performance and/or the estimation of the ability of the system to deliver the energy claimed by the
designer. In principle, two approaches for short-term system testing are referred to in this Technical
Specification:
1) A simplified check of short-term system performance, carried out by intercomparison of the
measured solar system heat gain with the one predicted by simulation, using the actual weather and
operating conditions as measured during the short-term test.
2) A short-term test for long-term system performance prediction. The performance of the most relevant
components of the solar heating system is measured for a certain time period while the system is in
normal operation. More detailed measurements encompass:
i) energy gain of collector array(s); and
ii) energy balance over storage vessel(s).
Intercomparison of the observed and simulated energy quantities provides the indirect validation of
collector and storage design parameters. The measured data within the collector array are also used
for direct identification of the collector array parameters. As far the component parameters are
verified, the long-term prediction of the system gain as well as the detection of possible sources of
system malfunctioning are possible.
Annex D describes a procedure for long-term monitoring as a part of the supervision of a large custom
built solar heating system. The objectives of supervision may be:
3) the early recognition of possible failures of system components, in order to get the maximum benefit
from the initial solar investment as well as to minimize the consumption of non-solar energy and the
resulting environmental impact;
4) the measurement of system performance (solar gains or other system indicators), if requested by a
contractual clause, e.g. guaranteed results.
The long-term monitoring in Annex D is limited to the solar energy specific aspects, especially to the
determination of the solar contribution to the total heat load. Instrumentation used in the long-term
monitoring should be an integrating part of the system, a part included from the very beginning of the
design process. If adequately foreseen, it may also be used for system adjustment at start time.
1 Scope
This Technical Specification applies to small and large custom built solar heating systems with liquid heat
transfer medium for residential buildings and similar applications, and gives test methods for verification of the
requirements specified in CEN/TS 12977-1.
This document also includes a method for thermal performance characterization and system performance
prediction of small custom built systems by means of component testing and system simulation.
Furthermore, this document contains methods for thermal performance characterization and system
performance prediction of large custom built systems.
This document applies to the following types of small custom built solar heating systems:
 systems for domestic hot water preparation only;
 systems for space heating only;
 systems for domestic hot water preparation and space heating;
 others (e.g. including cooling).
This document applies to large custom built solar heating systems, primarily to solar preheat systems, with
one or more storage vessels, heat exchangers, piping and automatic controls and with collector array(s) with
forced circulation of fluid in the collector loop.
This document does not apply to:
 systems with a store medium other than water (e.g. phase-change materials);
 thermosiphon systems;
 integral collector-storage (ICS) systems.
2 Normative references
The following referenced documents are indispensable for the application 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.
EN 307, Heat exchangers — Guidelines to prepare installation, operating and maintenance instructions
required to maintain the performance of each type of heat exchangers
EN 806-1, Specifications for installations inside buildings conveying water for human consumption — Part 1:
General
EN 809, Pumps and pump units for liquids — Common safety requirements
EN 1151-1, Pumps — Rotodynamic pumps — Circulation pumps having a rated power input not exceeding
200 W for heating installations and domestic hot water installations — Part 1: Non-automatic circulation
pumps, requirements, testing, marking
EN 1991-1-3, Eurocode 1: Actions on structures — Part 1-3: General actions — Snow loads
EN 1991-1-4, Eurocode 1: Actions on structures — Part 1-4: General actions — Wind actions
EN 12975-1:2006, Thermal solar systems and components — Solar collectors — Part 1: General
Requirements
EN 12975-2:2006, Thermal solar systems and components — Solar collectors — Part 2: Test methods
EN 12976-1:2006, Thermal solar systems and components — Factory made systems — Part 1: General
requirements
EN 12976-2:2006, Thermal solar systems and components — Factory made systems — Part 2: Test methods
CEN/TS 12977-1:2010, Thermal solar systems and components — Custom built systems — Part 1: General
requirements for solar water heaters and combisystems
EN 12977-3:2008, Thermal solar systems and components — Custom built systems — Part 3: Performance
test methods for solar water heater stores
CEN/TS 12977-4:2010, Thermal solar systems and components — Custom built systems — Part 4:
Performance test methods for solar combistores
CEN/TS 12977-5:2010, Thermal solar systems and components — Custom built systems — Part 5:
Performance test methods for control equipment
EN 60335-1, Household and similar electrical appliances — Safety — Part 1: General requirements
EN ISO 9488:1999, Solar energy — Vocabulary (ISO 9488:1999)
ISO 9459-5:2007, Solar heating — Domestic water heating systems — Part 5: System performance
characterization by means of whole system tests and computer simulation
ISO/TR 10217, Solar energy — Water heating systems — Guide to material selection with regard to internal
corrosion
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 12975-1:2006, EN 12976-1:2006,
CEN/TS 12977-1:2010, EN 12977-3:2008, CEN/TS 12977-4:2010, CEN/TS 12977-5:2010, ISO 9459-5:2007
and EN ISO 9488:1999 apply.
4 Symbols and abbreviations
Symbol Definition Unit
heat loss coefficient at (ϑ – ϑ ) = 0
a m a W/m K
A reference area of collector m²
c
C effective thermal capacity of collector or collector array J/K
c
Day day number of the year
Ds shift term for the calculation of mains water temperature at reference
location
f fractional energy savings %
sav
f solar fraction %
sol
G diffuse solar irradiance on tilted plane W/m²
d
Symbol Definition Unit
G global solar irradiance on horizontal plane W/m²
g
G hemispherical solar irradiance on tilted plane W/m²
h
H hemispherical solar irradiance on collector plane W/m²
c
K incidence angle modifier
ατ
Q gross auxiliary energy demand of the solar heating system MJ
aux
Q net auxiliary energy demand of the solar heating system delivered by the MJ
aux,net
auxiliary heater to the store or directly to the heat distribution system
Q gross energy demand of the conventional heating system MJ
conv
Q net energy demand of the conventional heating system MJ
conv,net
Q heat demand MJ
d
Q energy delivered at the outlet of the solar heating system MJ
L
Q store heat losses of the solar heating system MJ
l
Q store heat losses of the store heated by auxiliary energy (in case of a two- MJ
l,a
store-solar-plus-supplementary system)
Q store heat losses of the store heated by solar energy (in case of a two- MJ
l,s
store-solar-plus-supplementary system)
Q store heat losses of the conventional heating system MJ
l,conv
Q heat diverted from the store as active overheating protection, if any MJ
ohp
Q parasitic energy (electricity) for the collector loop pump(s) and control unit MJ
par
Q energy savings due to the solar heating system MJ
sav
Q energy delivered by the collector loop to the store MJ
sol
ϑ yearly average mains water temperature on reference location °C
average
ϑ collector ambient or surrounding air temperature °C
a
ϑ store ambient air temperature °C
S,amb
ϑ collector or collector array inlet/outlet fluid temperature °C
ci/co
ϑ mains water temperature °C
cw
ϑ desired hot water temperature °C
d
ϑ mean collector fluid temperature; ϑ = (ϑ + ϑ)/2 °C
m m ci co
ϑ fluid temperature at circulation loop inlet °C
rci
ϑ fluid temperature at circulation loop outlet °C
rce
θ required temperature for sensor high-temperature resistance °C
req
ϑ storage draw-off temperature °C
S
θ sensor temperature °C
sens
ϑ temperature for which controller operation starts/stops °C
start/stop
ϑ temperature of the storage tank °C
tank
T* reduced temperature difference; T* = (ϑ – ϑ )/G m K/W
m a h
Symbol Definition Unit
(UA) heat transfer capacity rate of a heat exchanger W/K
hx
(UA) heat loss capacity rate of the store of the solar heating system W/K
S
W/K
(UA) heat loss capacity rate of the store of the conventional heating system
S,conv
W/m²K
U overall heat loss coefficient of a collector or collector array
L
V demanded (daily) load volume l/d
d
V store volume of the conventional heating system l
S,conv
&
V volume flow rate in collector loop l/h
c
&
V volume flow rate in circulation loop l/h
rc
&
V volume draw-off flow rate from storage l/h
s
m/s
v surrounding air speed
∆ϑ temperature difference °C
∆ϑ average amplitude of seasonal mains water temperature variations on °C
amplit
reference location
η zero-loss collector efficiency (efficiency at T* = 0)
η overall generation efficiency of the auxiliary heater of the solar heating
aux
system
η overall generation efficiency of the heater of the conventional heating
conv
system
∆η drop in system efficiency induced by a heat exchanger %
∆ϑ average temperature difference induced by a heat exchanger °C

5 System classification
See CEN/TS 12977-1:2010, Clause 5.
6 Test methods
Subsequent test methods refer to the requirements given in CEN/TS 12977-1.
6.1 General
6.1.1 Suitability for drinking water
See EN 806-1.
6.1.2 Water contamination
Check the design of all circuits to avoid water contamination for backflow from all circuits to drinking main
supplies.
6.1.3 Freeze resistance
See EN 12976-2:2006, 5.1.
6.1.4 High-temperature protection
6.1.4.1 Scald protection
If the temperature of the domestic hot water in the system can exceed 60 °C, check the design plan or the
system documentation to see whether the system is provided with an automatic cold water mixing device or
any other device to limit the maximum tapping temperature to 60 °C.
6.1.4.2 High-temperature protection of materials
Ensure by checking the hydraulic scheme and/or by calculation and taking into account the most adverse
conditions for the materials of all parts of the system, that the maximum temperatures which may occur do not
exceed the maximum permissible temperatures for the respective materials, taking into account also pressure
conditions if relevant.
NOTE Both transients (high-temperature peaks of short duration) and stagnation of longer duration may create
adverse conditions for the respective material.
6.1.5 Reverse circulation prevention
Check the hydraulic scheme included in the documentation (see 6.7) to ensure that no unintentional reverse
circulation will occur in any hydraulic loop of the system.
6.1.6 Pressure resistance
In case that it is not documented that the store(s) and the heat exchanger(s) withstand at least 1,5 times the
manufacturer's stated maximum individual working pressures, the procedures specified in EN 12976-2:2006,
5.3 should be applied on the store(s) and the heat exchanger(s).
NOTE EN 12976-2:2006, 5.3 specifies a pressure resistance test method for a complete solar thermal system. For
the purpose of this clause this method should be applied on the store(s) and heat exchanger(s) principally.
Check if the system documentation for the installer describes a pressure resistance test procedure for the
collector loop of the system.
6.1.7 Electrical safety
See EN 60335-1.
6.2 Materials
Check if the documentation for the installer includes information about the durability of the materials exposed
to weathering with regard to UV radiation and other weather conditions.
Check if the materials used in the collector loop comply with ISO/TR 10217 concerning internal corrosion.
6.3 Components and pipework
6.3.1 Collector and collector array
The collector should be tested according to EN 12975-2.
The design of the collector array should be checked with regard to flow distribution.
6.3.2 Supporting frame
Check the calculation proving the resistance of the frame to snow and wind loads in accordance with
EN 1991-1-3 and EN 1991-1-4 where applicable.
6.3.3 Collector and other loops
With regard to the collector loop check if the requirements listed in CEN/TS 12977-5:2010, Table 10 are
fulfilled.
6.3.4 Circulation pump
See EN 809, EN 1151-1 and CEN/TS 12977-5.
6.3.5 Expansion vessels
6.3.5.1 General
For systems without a separate expansion vessel (e.g. drain-back systems) check both by calculation and the
hydraulic scheme to see whether the integrated expansion facility is able to fulfil its task.
6.3.5.2 Open expansion vessels
Check the volume and design of the open expansion vessel by calculation and by checking the hydraulic
scheme.
In addition, check the connection of the vessel to the atmosphere, the spill line and the expansion lines on the
hydraulic scheme.
6.3.5.3 Closed expansion vessels
For small custom built systems only: Check the fulfilment of the requirements given in CEN/TS 12977-1:2010,
6.3.5.2, by calculation and by visual check of the hydraulic scheme and operating instruction.
6.3.6 Heat exchangers
Apart from the tests in compliance with EN 307, check the design of the heat exchanger(s) with respect to
scaling or the availability of cleaning facilities.
In addition, the drop in system efficiency ∆η induced by a heat exchanger in the collector loop of a small
custom built system should be estimated by Equation (1):
η A a
0 c 1
∆η = 100 % (1)
(UA)
hx
For small systems (UA) is delivered by the store performance test of EN 12977-3 or CEN/TS 12977-4
hx
((UA) to be chosen for store temperatures of 20 °C, an average temperature difference of 10 K and a flow
hx
rate similar to the one used for the determination of the collector parameters). For large systems (UA) is
hx
taken from the heat exchanger performance data sheet provided by the manufacturer.
NOTE 1 In the latter case, since performance data of external heat exchangers (which are mostly used in large custom
built systems) are generally quite reliable, no additional measurements are needed.
For heat exchangers in other loops (e.g. a load side heat exchanger), the average temperature difference on
the primary side ∆ϑ which is induced by the presence of the heat exchanger should be estimated by
calculation. The drop in efficiency may then be
...