SIST-TP CWA 16975:2017

SLOVENSKI STANDARD
SIST-TP CWA 16975:2017
01-november-2017
Eko učinkovite postaje za daljinsko ogrevanje
Eco-efficient Substations for District Heating
Öko-effiziente Unterstationen
Ta slovenski standard je istoveten z: CWA 16975:2015
ICS:
27.010 Prenos energije in toplote na Energy and heat transfer
splošno engineering in general
91.140.10 Sistemi centralnega Central heating systems
ogrevanja
SIST-TP CWA 16975:2017 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST-TP CWA 16975:2017

---------------------- Page: 2 ----------------------
SIST-TP CWA 16975:2017


CEN
CWA 16975

WORKSHOP
December 2015

AGREEMENT


ICS 27.010; 91.140.10
English version


Eco-efficient Substations for District Heating
This CEN Workshop Agreement has been drafted and approved by a Workshop of representatives of interested parties, the
constitution of which is indicated in the foreword of this Workshop Agreement.

The formal process followed by the Workshop in the development of this Workshop Agreement has been endorsed by the
National Members of CEN but neither the National Members of CEN nor the CEN-CENELEC Management Centre can be held
accountable for the technical content of this CEN Workshop Agreement or possible conflicts with standards or legislation.

This CEN Workshop Agreement can in no way be held as being an official standard developed by CEN and its Members.

This CEN Workshop Agreement is publicly available as a reference document from the CEN Members National Standard Bodies.

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



EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2015 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members.


Ref. No.:CWA 16975:2015 E

---------------------- Page: 3 ----------------------
SIST-TP CWA 16975:2017
CWA 16975:2015 (E)
Contents
Page
European Foreword .4
1 Scope .5
2 Conformance .5
3 Technical Part.8
3.1 Introduction.8
3.2 Terms and definitions.8
3.3 Eco-efficient substation (EES) definition .10
3.3.1 General.10
3.3.2 Marking of EES.11
3.3.3 Commissioning, service and maintenance of EES.11
3.3.4 Choice of materials .11
3.4 Connection principles and standardized schemes .12
3.4.1 General Scheme of a substation .12
3.4.2 Parallel connection.12
3.4.3 Two step connection .12
3.5 Efficiency of Substation .13
3.5.1 Temperature and pressure levels in DH network.13
3.5.2 Low temperature system .14
3.5.3 Pressure drop .14
3.5.4 Efficiency of heat exchangers .15
3.5.5 Procedure to determine heat exchanger return temperature (T12).15
3.6 Domestic hot water system.16
3.6.1 Functionalities.16
3.6.2 Choice of materials .17
3.6.3 Temperatures, Environmental and Health Requirements for the domestic hot water .17
3.6.4 Dimensioning .17
3.7 Heating systems.17
3.7.1 Dimensioning of Heat Exchangers for heating services.17
3.7.2 Temperature levels for heating systems .18
3.8 Control system and communication.18
3.8.1 General.18
3.8.2 Delivered heat control .18
3.8.3 DHW control system .18
3.8.4 Accuracy of control system .19
3.8.5 Advanced features.19
3.9 Substation components -including heat exchanger, pump, safety equipment, valves .20
3.9.1 Generalities about the components.20
3.9.2 Filter .21
3.9.3 Control valve .21
3.9.4 Piping .21
3.9.5 Sensors.21
3.9.6 Pumps:.22
3.10 Insulation: .22
2

---------------------- Page: 4 ----------------------
SIST-TP CWA 16975:2017
CWA 16975:2015 (E)
4 Environmental Part .22
4.1 Environmental part General .22
4.2 Heat losses in substation.23
4.3 Pressure losses in secondary side heating .24
4.4 Cooling of the return temperature .24
4.4.1 General.24
4.4.2 Demands to Space Heating .25
4.4.3 Demands to DHW.26
4.5 Energy saving functions .27
4.5.1 General.27
4.5.2 Control and limitation of max capacity / primary flow.27
4.5.3 Indoor temperature data .27
4.5.4 Remote monitoring and control .28
4.5.5 Eco function.28
4.6 Labelling system.29
4.6.1 Eco-efficient substation labelling system and summary of rating points in case of
DHW and spice heating side(s).29
4.6.2 Eco-efficient substation labelling system and summary of rating points in case of
only spice heating side(s) .30
5 Testing and certification part.31
5.1 Certification process.31
5.1.1 Introduction.31
5.1.2 Object .31
5.1.3 General rules .31
5.1.4 Administration, Organisation .32
5.1.5 Certification procedure.32
5.1.6 Conditions for certification and quality marking .34
5.2 Testing procedures.37
5.2.1 Assumption and preparations .37
5.2.2 Test methods .44



3

---------------------- Page: 5 ----------------------
SIST-TP CWA 16975:2017
CWA 16975:2015 (E)
European Foreword
CWA 16975 is a technical agreement, developed and approved by an open, independent Workshop
structure within the framework of the CEN-CENELEC system. CWA 16975 reflects the agreement only
of the registered participants responsible for its content, and was developed in accordance with the
CEN-CENELEC rules and practices for the development and approval of CEN/CENELEC Workshop
Agreements. CWA 16975 does not have the status of a European Standard (EN) developed by CEN and
its national Members. It does not represent the wider level of consensus and transparency required for
a European Standard (EN) and is not intended to support legislative requirements or to address issues
with significant health and safety implications. For these reasons, CEN are not accountable for the
technical content of CWA 16975 or for any possible conflicts with national standards or legislation. The
Workshop participants who drafted and approved CWAWS 73 are indicated in the Foreword. The
copyright in CWA VW 73 is owned exclusively by CEN. Copies of CWA VS 73 are available from the
[national standards bodies of the following countries: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
Foreword
CWA 16975 was developed in accordance with CEN-CENELEC Guide 29 “CEN/CENELEC Workshop
Agreements – The way to rapid agreement” and with the relevant provisions of CEN/CENELEC Internal
Regulations - Part 2. It was agreed on 2015-09-11 in a Workshop by representatives of interested
parties, approved and supported by CEN following a public call for participation made on 2015-09-11. It
does not necessarily reflect the views of all stakeholders that might have an interest in its subject
matter.
The final text of CWA 16975 was submitted to CEN for publication on 2015-11-19. It was developed and
approved by: Paolo Arrus - Giacomini, Anna Boss - SP Swedish National Testing and Research Institut,
Aleš Cjuha - Energetika Ljubljana, Daniele Delboca - Giacomini, Mieczyslaw Dzierzgowski - OPEC
Gdynia, Bertrand Guillemot- Dalkia France, Niklas Jeppsson - SWEP International, Markus Köfinger -
AIT, Alexander Midtsjø - Hafslund Varme, Gunnar Nilsson - Svensk Fjärrvärme, Timo Peltola-Ouman,
Igor Radovic - Grundfos Holding, Fabrice Renaude - Gylergie Cofely's Research Center, Henrik Rietz -
SWEP International, Marko Riipinen - Helsinki Energy, Janusz Rozalski - OPEC Gdynia, Jaroslaw
Szczechowiak - OPEC Gdynia, Jan Eric Thorsen – Danfoss, Jonas Wallenskog - Svensk Fjärrvärme, Wim
Wolfs- Giacomini, Teijo Aaltonen - Alfa Laval Nordic.
It is possible that some elements of CWA 16975 will be subject to patent rights. The CEN-CENELEC
policy on patent rights is set out in CEN-CENELEC Guide 8 “Guidelines for Implementation of the
Common IPR Policy on Patents (and other statutory intellectual property rights based on inventions)”.
CEN shall not be held responsible for identifying any or all such patent rights.
The Workshop participants have made every effort to ensure the reliability and accuracy of the
technical and non-technical content of CWA 16975, but this does not guarantee, either explicitly or
implicitly, its correctness. Users of CWA 16975 should be aware that neither the Workshop participants,
nor CEN can be held liable for damages or losses of any kind whatsoever which may arise from its
application. Users of CWA 16975 do so on their own responsibility and at their own risk.


4

---------------------- Page: 6 ----------------------
SIST-TP CWA 16975:2017
CWA 16975:2015 (E)
1 Scope
The target is to describe what is an eco-efficient substation (EES), how this eco-efficient substation is
considered, tested and certified. EES concept includes as much substation efficient design as possible,
without trying to cover an exhaustive point of view. The scope of the EES is to focus on a reachable
future, realistic compliance with the existing system and ways of handling substation issues in a
harmonized manner across Europe.
The proposed standard is compliable with the expected development in Europe in the future such as:
• New buildings with less demand for energy and more demands for lower temperatures.
• The connection systems should be standardized in order to make the substation replacement
as easy as possible.
The aim is to consider the whole life of the system, including all seasons and not only the peak load
operation. The most important period to consider, is the long duration time with both heating and
domestic hot water demands.
EES should be certified, and marked according to certification that is given according to testing result
and environmental ranking. Only EES with capacity up to 500kW per heat exchanger for heating and
domestic hot water respectively, can be certified. Small substations intended for single-family houses or
flats, shall not be certified. A certificate can include one specific substation or a series of substations.
This document contains 3 main parts:
Technical: Describes the main and optional components of the EES
Environmental: Describes the various parameter and components that give the efficiency to the
substation, how these are ranked and the marking procedure
Testing and certification: The testing and certification procedures.
2 Conformance
All DH equipment and the system as a whole shall be approved in accordance with international,
European Union and national laws, regulations, building codes and standards. In addition, all laws and
rules from the national health and environmental authorities shall be taken into consideration.
National DH organizations and Euroheat & Power should make efforts towards harmonizing such rules
and standards throughout the EU, in order for these rules and standards to be as much as possible in
line with the characteristics of DH. The aforementioned organizations may also issue technical
recommendations themselves.
The following EU directives and standards are relevant for this document:
• Directive 2012/27/EU (EED directive): Energy efficiency directive introduces a framework of
measures to use energy more efficiently at all stages of energy chain. The directive is especially
focused on energy efficiency improvements in households, industry and transport sector.
• Directive 2010/31/EU (EPBD directive): Energy performance of buildings directive introduces
the new methodology for calculating the energy efficiency of buildings, minimum requirements
for energy efficiency of new and renovated buildings, minimum requirements for energy
5

---------------------- Page: 7 ----------------------
SIST-TP CWA 16975:2017
CWA 16975:2015 (E)
efficiency of building equipment, plans for implementing more nearly zero energy buildings,
regular inspections of heating and air conditioning systems in buildings and implementation of
energy performance certificates for buildings.
• Directive 2010/30/EU: Directive establishes a framework for labelling and introducing
general product information on consumption of energy and other energy-related products.
• Directive 2009/125/EC: Directive represents a framework for minimum Eco design
requirements of product that use energy and water (light bulbs, refrigerators, heat Owen,
insulation materials, etc.).
• Regulation No. 641/2009 with amending regulation No. 622/2012 and regulation No.
547/2012: Regulations present eco-design requirements for water pumps.
• Directive 2004/22/EC (MID directive): Measuring instrument directive specifies
methodology and requirements for measuring instruments such as heat, water, gas and electric
energy meters, exhaust gas analysers, taximeters, etc.
• Directive 98/83/EC (DWD directive): Drinking water directive sets the minimum standards for
quality of drinking water in distribution systems, regarding microorganisms and chemical
parameters.
• Directive 97/23/EC (PED directive): Pressure equipment directive presents requirements for
design and fabrication of pressure equipment such as pressure vessels, piping, safety valves and
other components subjected to pressure load.
• Regulation EC 66/2010 (ECO labelling): Regulation presents rules for application of voluntary
environmental labelling system for eco-friendly products.
• European standard EN 1434 (Heat meters standard): Standard specifies minimum
requirements for heat meters regarding construction, data exchange, testing, verification,
installation, commissioning, monitoring and maintenance.
• European standard EN 13445 (Pressure vessels standard): Standard specifies requirements for
design, construction, inspection and testing of unfired pressure vessels made from steel, cast
iron and aluminium.
• European standard EN 1148:1998, EN 1148:1998/A1:2005 (Heat exchangers standard):
Standard specifies test procedures for establishing the performance data of water to water heat
exchangers for district heating.
• European standard EN 247:1997 (Heat exchangers standard): Standard specifies heat
exchangers terminology.
• European standard EN 12828:2012 (Heating systems in buildings standard): Standard specifies
the design of water based heating systems.
• European standard EN 14336:2004 (Heating systems in buildings standard): Standard specifies
the installation and commissioning of water based heating systems.
6

---------------------- Page: 8 ----------------------
SIST-TP CWA 16975:2017
CWA 16975:2015 (E)
• European standard EN 15316 series (Heating systems in buildings standard): Standard
specifies methods for calculation of system energy requirements and system efficiencies; with
special focus on Part 4-5 'Space heating generation systems, the performance and quality of
district heating and large volume systems.
All electrical components of the EES shall be electrically protected according to the applicable rules.
7

---------------------- Page: 9 ----------------------
SIST-TP CWA 16975:2017
CWA 16975:2015 (E)
3 Technical Part
3.1 Introduction
The aim of this part is to describe the technical specifications that a substation has to fulfil to be
regarded as an Eco-efficient substation.
3.2 Terms and definitions
Here is a simplified drawing of a substation that gives the location of the various components described
in the definition.

District Heating
Customer side
T T
11 42
DH supply

DHW supply T° DHW
T° supply
∆P
T DHW
31
T
41 T
Pressure Supply PS 61
DHW Circulation (T° C)
T
51
Cold water (T° CW)
∆P
DH
SUBSTATION
T22
Heating supply
DH return T° HS
∆P
Heating
T
12 T
21
T° return
PR Pressure return Heating return
T
32
T° HR

Figure 1 - Definition drawing
DHW: Domestic Hot Water: Water heated for sanitary use.
DHW circulation loop: Piping where DHW continuously flows in order to keep the system active and the
temperature on such a level that both comfort and health requirements are delivered to the customer.
Cold Water: Is the fresh water coming from the water services that feed the DHW system.
DH: District Heating Network.
ΔP: Pressure difference between supply and return pipes.

8

---------------------- Page: 10 ----------------------
SIST-TP CWA 16975:2017
CWA 16975:2015 (E)

Definition of variables in a counter-flow heat exchanger
T Primary supply temperature from DH,
11 :
T Heating supply temperature, to customer,
22:
T Primary return temperature to DH,
12:
T21: Heating return temperature, from customer,
T DHW: Primary supply temperature from DH,
31:
T DHW supply temperature to customer,
42:
T DHW Primary return temperature to DH,
32:
Figure 2 - Variables in a heating counter-flow
heat exchanger
T DHW cold water and circulation loop temperature,
41:
ΔΤ2 Temperature difference secondary side,
T51: Cold Water temperature,
T61: Circulation loop return temperature,
ϑ Temperature difference heating (T12–T21) or DHW
1
side (T32– T41),
ϑ2 Temperature difference Primary side (T11–T22) or (T31–
T ).
42

Figure 3 - Variables in a DHW counter-flow heat

exchanger

9

---------------------- Page: 11 ----------------------
SIST-TP CWA 16975:2017
CWA 16975:2015 (E)
In this document, the following verbal forms are used:
• “Shall” indicates a requirement
• “Should” indicates a recommendation;
• “May” indicates a permission;
• “Can” indicates a possibility or a capability.
3.3 Eco-efficient substation (EES) definition
3.3.1 General
The purpose of this document is to describe what an Eco-efficient substation is. The substation is the
system in a district heating network, that connects the customer or group of customers to the network.
It complies with European and local regulations. Many various system designs are existing and this
document will describe those that provide the best ratio between energy efficiency, life cycle cost, the
most common use and new services that the substation might provide.
The EES provides both heat service (HS) and domestic hot water production (DHW) or the systems
might be considered separately if just one of the two is needed. It is suitable to consider Rehva request
and/or bacteriological risks according to national regulations when DHW is planned and installed.
To be efficient the Eco-efficient Substation (EES) shall deliver a reasonably low return temperature to
the network and create a reasonably low pressure drop across the system on the secondary side.
The EES shall be equipped to provide the customer and the district heating company with a secure,
energy effective and economically reliable connection to the DH-network. To achieve this target, the
EES shall include at least:
• One efficient heat exchanger per service such as brazed heat exchanger or any other
technology that provide the similar efficient service.
• Each heat exchanger shall be insulated.
• Control valve to control the energy delivered and control the temperature delivered to the
customer in an as efficient manner as possible. A control valve for temperature control
acts on the primary side for each service, heating and DHW.
• Filter should be installed on primary side
• Heat meter should be mounted according to EN 1434.
The number, quality and range of the devices shall be adjusted to the size of the substation. EES shall be
insulated to prevent heat losses, risk of injury and high ambient temperature in the substation room.
Other components can increase the scope of the services of the EES, but as they are strongly linked to
where they have to be implemented in the sizing and design, they are not in the scope of this document.
These compo
...