PUBLIC REVIEW DRAFT, SEPTEMBER 2008KENYA STANDARD  KS 1855-1:2008  
ICS 27.160; 97.100.99 
  
 
 
  
 
  
 
  
 
Thermal solar systems and components — 
Custom built systems — Part 1: General 
requirements 
 
  
 
 
 
 
  
 
  
 
Public Review Draft, September 2008  
 
 
  
 
  
 
  
 
 
© KEBS 2008 Edition 1.0 
 PUBLIC REVIEW DRAFT, SEPTEMBER 2008KS 1855-1:2008 
ii © KEBS 2008 — All rights reserved  
TECHNICAL COMMITTEE REPRESENTATION 
 
The following organizations were represented on the Technical Committee 
 
Kenital Solar (K) Ltd  
ASP Solar (Kenya) Ltd  
Sollatek Ltd  
Department of Electrical & Electronic Engineering, JKUAT  
Renewable Energy Department, Ministry of Energy  
Chloride Exide Kenya Limited  
Energy Alternatives Africa Ltd  
Solarnet  
Automotive and Industrial Battery Manufacturers (AIBM) (K) Ltd 
RENCON Associates  
Telesales Solar Ltd 
Kenya Industrial Research and Development Institute, KIRDI 
Kenya Bureau of Standards — Secretariat 
 
 
 
 
  
 
 
 
 
  
REVISION OF KENYA STANDARDS 
 
In order to keep abreast of progress in industry, Kenya standards shall be regularly reviewed. Suggestions for 
improvement to published standards, addressed to the Managing Director, Kenya Bureau of Standards, are 
welcome. 
 
© Kenya Bureau of Standards, 2008 
 
Copyright. Users are reminded that by virtue of Section 25 of th e Copyright Act, Cap. 12 of 2001  of the Laws of Kenya, copyrig ht 
subsists in all Kenya Standards and except as provided under Section 26 of this Act, no Kenya Standard produced by Kenya Bureau  of 
Standards may be reproduced, stored in a retrieval system in any form or transmitted by any means without prior permission in w riting 
from the Managing Director. 
 
 
 
 
 
 
   
 
 
 
 
 
 PUBLIC REVIEW DRAFT, SEPTEMBER 2008KS 1855-1:2008 
ICS 27.160; 97.100.99  
© KEBS 2008 — All rights reserved iii  
 
 
 
 
 
 
 
 
  
 
 
Thermal solar systems and components — 
Custom built systems — Part 1: General 
requirements 
 
 
  
 
 
  
 
  
 
 
KENYA BUREAU OF ST ANDARDS (KEBS) 
 
Head  Office:  P.O. Box 54974, Nairobi-00200, Tel.: (+254  020) 605490, 602350, Fax: (+254 020)  604031 
E-Mail: info@kebs.org,  Web:http://www.kebs.org   
 
KEBS Coast Region 
P.O. Box 99376, Mombasa 80100 
Tel: (+254 041) 229563, 230939/40 Fax: (+254 041) 229448 
E-mail: kebs-msa@swiftmombasa.com
 KEBS Lake Region 
P.O. Box 2949, Kisumu 40100 
Tel: (+254 057) 23549,22396 Fax: (+254 057) 21814 E-mail: kebs-ksm@swiftkisumu.com
 KEBS North Rift Region 
P.O. Box 2138, Nakuru 20100 
Tel: (+254 051) 210553, 210555
 PUBLIC REVIEW DRAFT, SEPTEMBER 2008KS 1855-1:2008 
iv © KEBS 2008 — All rights reserved  
Foreword 
 
This Kenya standard was developed by the Renewable Energy Resources Technical Committee under the supervision of the Electrical Industry Standards Committee and is in accordance with the procedures of the 
Bureau. 
 
This Kenya Standard specifies requirements on durability,  reliability and safety of small and large custom built 
solar heating systems with liquid heat transfer medium  for residential buildings and similar applications. The 
standard contains also requirements on the design process of large custom built systems. 
 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 standard:  
a) This standard provides no information as to whether the product may be used without restriction; 
 
b) It should be noted that, while awaiting the adoption of a verifiable criteria, existing national 
regulations concerning the use and/or the characteristics of this product remain in force. 
 
Factory Made and Custom Built solar heating systems 
 
Large Custom Built systems are uniquely designed for a specific situation. In general HVAC engineers, 
manufacturers or other experts design them.  
Small Custom Built systems offered by a company are de scribed 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. PUBLIC REVIEW DRAFT, SEPTEMBER 2008KS 1855-1:2008  
© KEBS 2007 — All rights reserved v  
Contents 
 
1 Scope ....................................................................................................................... .................................. 1 
2 Normative references ........................................................................................................ ......................... 1 
3 Terms and definitions ....................................................................................................... .......................... 2 
4 Symbols and abbreviations ................................................................................................... ..................... 3 
5 System classification ....................................................................................................... ........................... 3 
5.1 Small custom built systems ................................................................................................ ............... 3 
5.2 Large custom built systems ................................................................................................ ............... 3 
6 Requirements ................................................................................................................ ............................. 4 
6.1 General ................................................................................................................... ........................... 4 
6.2 Materials ................................................................................................................. ........................... 5 
6.3 Components and pipework ................................................................................................... ............. 5 
6.4 Safety equipment and indicators ........................................................................................... ............ 8 
6.5 Installation .............................................................................................................. ............................ 9 
6.6 Initial operation and commissioning ....................................................................................... ........... 9 
6.7 Documentation ............................................................................................................. .................... 10 
6.8 System performance ........................................................................................................................ 11 
 
 
 
 
 PUBLIC REVIEW DRAFT, SEPTEMBER 2008PUBLIC REVIEW DRAFT, SEPTEMBER 2008KENYA STANDARD KS 1855-1:2008  
© KEBS 2008 — All rights reserved 1  
 
Thermal solar systems and components  — Custom built systems — Part 
1: General requirements  
 
 1 Scope 
 
This Kenya Standard specifies requirements on durability,  reliability and safety of small and large custom built 
solar heating systems with liquid heat transfer medium  for residential buildings and similar applications. The 
standard contains also requirements on the design process of large custom built systems. 
 
2 Normative references 
 
The following referenced documents are indispensable for the application of this Kenya Standard. For dated 
references, only the edition cited applies. For undated re ferences, the latest edition of the referenced document 
(including any amendments) applies.  
 
ISO 21003-1, Multilayer piping systems for hot and cold water installations inside buildings — Part 1: General  
 
ISO 21003-3, Multilayer piping systems for hot and cold water installations inside build ings — Part 3: Fittings  
 
ISO 21003-5, Multilayer piping systems for hot and cold water installations inside buildings — Part 5: Fitness 
for purpose of the system  
 
EN 806-1, Specifications for installations inside buildings conveying water for human consumption — Part 1: 
General 
 
ISO 9774, Thermal insulation for building applications  — Guidelines for selecting properties  
 
ISO 6612, Windows and door height windows — Wind resistance tests  
 
ISO 15783, Seal-less rotodynamic pumps — Class II — Specification  
 
ISO 9906, Rotodynamic pumps — Hydraulic performance acceptance tests — Grades 1 and 2  
 
EN 1717, Protection against pollution of potable water in drinking water installations and general 
requirements of devices to prevent pollution by backflow  
 
ISO 1129, Steel tubes for boilers, superheaters and heat exchangers — Dimensions, tolerances and 
conventional masses per unit length 
 
ISO 16528, Boilers and pressure vessels  
 
KS 1851-1, Thermal solar systems and components — Solar collectors — Part 1: General Requirements  
 
KS 1851-2, Thermal solar systems and components — Solar collectors — Part 2: Test methods  
 KS 1852-1, Thermal solar systems and components — Factory made systems — Part 1: General 
requirements  
 
KS 1855-2, Thermal solar systems and components — Custom built systems — Part 2: Test methods  
 
KS 1855-3, Thermal solar systems and components — Custom built systems — Part 3: Performance 
characterization of stores for solar heating systems  PUBLIC REVIEW DRAFT, SEPTEMBER 2008KS 1855-1:2008 
2 © KEBS 2008 — All rights reserved  
IEC 60335-1, Safety of household and similar electrical appliances — Part 1: General requirements  
 IEC 60335-2-21, Safety of household and similar electrical appliances — Part 2: Particular requirements for 
storage water heaters  
 
IEC 61024-1, Protection of structures against lightning — Part 1: General principles  
 ISO 9488, Solar energy — Vocabulary  
 
ISO 9459-1, Solar heating — Domestic water heating systems — Part 1: Performance rating procedure using 
indoor test methods  
 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 standard, the terms and definitions given in KS 1851-1, KS 1852-1 and ISO 9488 apply together with the following. 
 
3.1 
assortment complete list of components (collectors, stores, controllers, pumps etc.) which a company offers for its solar heating systems. For the purpose of this standard the assortment is restricted to components used for small 
custom built solar heating systems marketed by a company 
 
3.2 assortment file 
technical documentation file for small custom built systems of a company which includes: 
 
⎯ the complete assortment fo r small custom built systems 
 
⎯ the complete description of all system configurations 
 
⎯ the complete description of all marketed combinations of system configurations and components 
including the component dimensions and number of units 
 ⎯ further technical information 
 
3.3 
collector array group of collectors that are closely connected in series, in parallel or in combination of both modes, with one 
hydraulic input and one hydraulic output 
 
3.4 
expansion line 
for systems with closed expansion vessels, the connecting line between the collectors and the pressure 
expansion vessel  
For systems with open expansion vessels, the connecting line between the collector array and the open 
expansion vessel  
3.5 
large custom built system 
solar heating system for the purpose of hot water preparation and/or space heating. It is designed for a 
specific situation by combining various components to a unique system. PUBLIC REVIEW DRAFT, SEPTEMBER 2008KS 1855-1:2008 
© KEBS 2008 — All rights reserved 3  
NOTE 1 In general, large custom built systems are designed by HVAC engineers, manufacturers or other experts. 
 
NOTE 2 In general the collector area is greater than 30 m2 and the store volume is greater than 3 m3. 
 
3.6 
safety line 
systems with closed expansion vessels: connecting line between the collector array and the safety valve 
 
Systems with open expansion vessels: connecting line between the collector array and the open expansion 
vessel 
 
3.7 small custom built system 
modular solar heating system of the remote storage type for the purpose of hot water preparation and/or 
space heating. The system has a well identified configuration (see definition in 3.8). It is assembled from 
components chosen from the market and described in an assortment file prepared by a company  
NOTE 1 In general the assortment file includes the possible system configurations, the assortment of components and their possi ble 
combinations and dimensions. The 'company' may be the manufacturer of all or of parts of the components in the assortment; this  
company may also be only a consulting engineer who just produces the technical documentation and purchases the components from 
suppliers.  
NOTE 2 In general the collector area is greater than 1 m2 and less than 30 m2 and the store volume is less than 3 m3. 
 
NOTE 3 The system can be tested by experimentally testing the components and predicting the system performance for different 
combinations of components by computer simulation. 
 
3.8 
system configuration 
characteristics of a solar heating system including its hydraulic scheme (hydraulic connections between the 
collector array, the store(s) and other components) and its control concept. Systems differing by any other 
parameter, by the type or dimensions of the used components or the controller settings are considered to have the same configuration  
4 Symbols and abbreviations 
 
(UA)S,a,sb stand-by heat loss rate of the store 
 V
S store volume 
 
5 System classification 
 
5.1 Small custom built systems 
 
Small custom built systems are classified as described in clause 5 of ISO 9459-1. According to the purpose 
of these systems the following additional classification applies (see Table 2):  
Table 2 — Classes of small custom built systems according to their purpose 
 
Class 
 Purpose 
 
A  domestic hot water preparation only  
B  space heating only  
C domestic hot water preparation and space heating 
 
5.2 Large custom built systems 
 
Large custom built systems are classified in accordance with Table 3. PUBLIC REVIEW DRAFT, SEPTEMBER 2008KS 1855-1:2008 
4 © KEBS 2008 — All rights reserved  
Table 3 — Classification of large systems 
 
Class Purpose 
A A system in which the store(s) and the collector array(s) are located in one building 
for which the heat is provided. No seasonal store and no heat distribution network 
outside the building are included. 
B A system which consists of a central heating plant and one or more collector 
array(s). The heat is transported via a heat distribution network to the heating plant 
and/or to other buildings. No seasonal store is included. 
C A large custom built system which mainly consists of one or more large collector 
array(s) and in which the heat is transferred to a seasonal store or directly into a heat distribution network. 
NOTE Large systems of type A are generally used for large multi-family houses. 
 Large systems of type B are generally used for district heating systems without any seasonal store.  
Large systems of type C are generally used for large district heating systems.
 
6 Requirements 
 
Subsequent requirements refer to the test methods given in KS 1855-2. 
 
NOTE The numbering of the following clauses is kept in direct correspondence to the numbering of KS 1855-2. 
 
6.1 General 
 
6.1.1 Suitability for drinking water 
 
See EN 806-1. 
 
6.1.2 Water contamination 
 
See EN 1717. 
 
NOTE See also the introduction about water quality. 
 
6.1.3 Freeze resistance 
 
See 4.1.3 of KS 1852-1. 
 
6.1.4 Overheating protection 
 
6.1.4.1 Scald protection 
 
Systems in which the temperature of the domestic hot water delivered to the user can exceed 60 °C, shall be 
fitted with an automatic cold water mixing device or any other device to limit the temperature to at maximum 
60 °C shall be installed. 
 
6.1.4.2 Overheating protection for materials  
The design of the system shall ensure that the highest permissible temperatures to which the system 
components may be exposed are not exceeded. 
 
NOTE Care should be taken in cases where under stagnation conditions steam or hot water can enter the collector pipes, pipework , 
distribution network or heat exchanger. 
 
6.1.5 Reverse flow prevention 
 
The installation of the system as described in the hydraulic scheme shall ensure that no unintentional reverse 
flow occurs in any hydraulic loop of the system. PUBLIC REVIEW DRAFT, SEPTEMBER 2008KS 1855-1:2008 
© KEBS 2008 — All rights reserved 5  
6.1.6 Pressure resistance 
 The store tank and the heat exchangers in this tank shall comply with the requirements given in ISO 16528. 
The collector shall comply with th e requirements given in KS 1851-1. 
 Any components in the systems which are not covered by ISO 16528 or KS 1851-1 shall withstand the lower 
of the following pressures: 
 
⎯ 1.5 times the manufacturer's stated maximum working pressure, 
 
⎯ the manufacturer's stated maximum test pressure 
 
for the part of the system in which these component is used. 
 
NOTE 1 In addition collector arrays of large custom built systems should be designed in a way, that they can also withstand sho rt and 
high pressure peaks. 
 
NOTE 2 If, due to stagnation, considerable heat transfer medium quantiti es in the collector array evaporate, pressure peaks may  occur 
due to high flow velocities of steam or liquid. These pressure peaks may significantly exceed the release pressure of the safet y valve. 
 
6.1.7 Electrical safety 
 
See IEC 60335-1 and IEC 60335-2-21. 
 
6.2 Materials 
 
Any parts of the system to be mounted outdoors shall be resistant to UV radiation and other weather 
conditions over the prescribed maintenance interval. When any maintenance or replacement of system parts is required in order to maintain the system's working order over a period of 10 years, this shall be clearly 
stated in the documents for the user. 
 
All materials used in the collector loop should comply  with ISO/TR 10217 in order to avoid any internal 
corrosion. 
 
6.3 Components and pipework 
 
6.3.1 Collector and collector array 
 
The collector shall meet the requirements given in KS 1851-1.  For parts and joints of the collector array see 6.3.8. 
 
NOTE 1 Care should be taken in order to ensure long term durability and tightness of the collector joints. 
 
If the collector array includes several parallel connected rows of collectors, the maximum disparity of the 
mass flow rate per unit collector area of each row should not exceed 20 % of the nominal flow rate per unit 
collector area of the whole array. 
 
NOTE 2 In general, balanced flow can be reached by means of hydraulic adjustment of collectors and tubes. If this is not possib le, the 
flow can be controlled by suitable fittings. 
 
6.3.2 Supporting frame 
 
If part of the system is installed on an outdoor frame, the resistance of the frame to wind loads in accordance 
with ISO 6612 shall be proved by calculation with reference to the local conditions. The manufacturer shall 
specify the maximum values for vm (mean wind velocity) according to ISO 6612. The system may only be PUBLIC REVIEW DRAFT, SEPTEMBER 2008KS 1855-1:2008 
6 © KEBS 2008 — All rights reserved installed at locations, where the values of vm determined according to ISO 6612 are lower than the maximum 
values stated by the manufacturer. This shall be mentioned in the documents for the installer (see also 6.7.2). 
 
6.3.3 Collector and other loops 
 
If the collector loop is provided with a circulation pump, the pressure drop in the whole loop should remain 
acceptable. The parasitic electrical power of the pump should not exceed the values given in Table 4. 
 
Table 4 — Maximum electrical power of the pump 
 
System 
 Electrical power of the pump  
Small systems 
 50 W or 2 % of the highest heat power which can be delivered by the collector array, whichever higher  
Large systems  1% of the highest heat power which can be delivered by the collector array  
 The maximum pump power stated above excludes the power of pumps in drain-back systems that is only 
needed to refill the system after drain-back. 
 
Other possible heat transfer loops within the system should be designed by comparing the parasitic power of 
their pump(s) to the highest heat power transmitted. 
 
6.3.4 Circulation pumps 
 
See ISO 9906 and ISO 15783. 
 
6.3.5 Expansion vessels 
 
For drain-back systems, a separate expansion vessel  is not necessary, when th e drain-back facility is 
adequately designed to fulfil its task, in terms of volume, temperature and pressure resistance. 
 6.3.5.1 Open expansion vessels 
 
Each open system shall be provided with an expansion vessel, the volume of which shall be dimensioned 
such that it is capable of absorbing at least the entire expansion of the heat transfer medium between the lowest and the highest possible operating temperature. Each expansion vessel shall be provided with a 
connection to atmosphere, which cannot  be shut off, and with a spill line. 
 
6.3.5.2 Closed expansion vessels  
For small systems: 
 The expansion device of the collector loop shall be dimensioned such, that even after an interruption of the 
power supply to the circulation pump in the collector loop just when solar irradiance is maximum, operation 
can be resumed automatically after power is available again. 
 
When the heat transfer medium can evaporate under stagnation conditions this rule implies a special 
dimensioning of the expansion volume: In addition to the dimensioning as it is usual for closed space heating 
systems (expansion of the whole heat transfer medium), the expansion vessel shall be able to compensate 
for the volume of the heat transfer medium in the whole collector array including all connection pipes between the collectors plus 10 %. 
 
Alternatively, when the system does not automatically resume operation after stagnation conditions, a warning shall be added to the operating instructions. 
 PUBLIC REVIEW DRAFT, SEPTEMBER 2008KS 1855-1:2008 
© KEBS 2008 — All rights reserved 7 The manufacturer's instructions shall be followed.  
 
No requirements for large systems. 
 
6.3.6 Heat exchangers 
 If the system is intended to be used in areas with high water hardness and at temperatures above 60 °C, heat 
exchangers in contact with drinking water shall be designed such that scaling is prevented or there shall be a 
means for cleaning.  
NOTE 1 High temperature difference between the metal surface of the heat exchanger and the surrounding drinking water mainly 
causes scaling. This can be avoided by increasing the heat exchanger area. 
 
Any heat exchanger(s) between the collector loop and the hot water supply system should not reduce the collector efficiency due to an increase of the collector's operating temperature by more than the following 
criterion specifies: 
 
When the solar gain of the collector has reached its highest possible value, the reduction of the collector 
efficiency induced by the heat exchanger should not exceed 10 % (absolute). If more than one heat exchanger is installed, this value should also not be exceeded by the sum of reductions induced by each of 
them. The criterion also applies if a load-side heat exchanger is part of the system. 
 
NOTE 2 If only one heat exchanger is used between the collector loop and the store of a small custom built system, the heat tra nsfer 
rate of the heat exchanger per unit collector area should not be less than 40 W/(K m2). 
 
6.3.7 Store 
 
Stores for drinking water and parts of combined stores which are in contact with drinking water shall comply 
with the requirements in ISO 16528. 
 Stores of small custom built systems should be tested as described in KS 1855-3. 
 
The stand-by heat loss rate ( UA)
S,a,sb of stores of small custom built systems should not exceed the value 
given by equation (1): 
 
(UA)S,a,sb = 0.16SV   in W/K (1) 
 
where VS is the nominal volume of the store in litres. 
 
NOTE Equation (1) is derived from figures specified in the Swiss regulation and the Italian code for hot water stores. 
 
No requirement on the heat loss rate of stores of large custom built systems.  
6.3.8 Pipework 
 
The pipe length of the system shall be as short as possible. The pipes and fittings shall be selected from 
materials that are compatible with the components included in each loop, according to the fluid of the loop as 
specified in the ISO/TR 10217. 
 
The design of the system and the used materials shall be such that there is no possibility of clogging and lime 
deposit in its circuits which would drastically influence the system performance. 
 
The pipework for drinking water shall comply with the requirements specified in EN 806-1. The materials for pipes and fittings shall be suitable to withstand the maximum operating temperature (stagnation conditions) and pressure. The pipework shall withstand thermal expansion without any damage or detrimental 
deformation. 
 
Venting of the system shall be possible. No automatic vents shall be placed in parts of the collector loop 
where vapour can occur (e.g. the top of the collector array), except a manual valve is foreseen between the PUBLIC REVIEW DRAFT, SEPTEMBER 2008KS 1855-1:2008 
8 © KEBS 2008 — All rights reserved pipe and the automatic vent, this valve being closed during normal operation of the system, or except a 
warning is added to the operating instructions, indicating that the system does not automatically resume 
operation after stagnation conditions. 
 
6.3.9 Thermal insulation 
 
The thermal insulation of all connecting pipes and other components of the system should comply with the 
requirements given in ISO 9774. 
 
The collector loop should be insulated without any gaps between the components. Thermal bridges, e.g. 
incorrectly installed mounting clamps should be avoided. 
 
The thermal insulation of the pipework shall be from materials which are resistant to the maximum 
temperature of the circuit and deformation and which remain operative. If the insulation is installed outside, it shall be protected from solar radiation, weather conditions and animal impact. 
 
Insulated pipes for underground installation shall comply with ISO 21003.  
6.3.10 Control system 
 
6.3.10.1 Controller 
 
The controller of a small custom built system should be tested as described in 7.3 of KS 1855-2.  
No requirement for large custom built systems. 
 
6.3.10.2 Temperature sensors 
 
The collector temperature sensor shall withstand stagnation conditions as specified in KS 1851-2 without 
altering by more than 1 K. 
 
The store temperature sensor shall withstand 100 °C without altering by more than 1 K. 
 The location and installation of all temperature sensors shall ensure a good thermal contact with the part of 
which the temperature shall be measured. The temperature sensors shall be insulated against ambient. 
 
6.4 Safety equipment and indicators 
 
6.4.1 Safety valves 
 
Each section of the collector array which can be shut off shall be fitted with at least one suitable safety valve 
of suitable dimension. The safety valve shall resist the temperature conditions which it is exposed to, especially the highest temperature that can occur. The safety valve shall resist the heat transfer medium. The 
safety valve shall be dimensioned such that it can release the highest flow of hot water or steam that can 
occur. The dimension of the safety valve(s) shall be proved by suitable means.  
6.4.2 Safety lines and expansion lines 
 
The safety line shall not be capable of being shut off. 
 
The safety line and expansion line shall be dimensioned such, that for the highest flow of hot water or steam 
that can occur, at no place in the collector loop the maximum allowed pressure is exceeded due to the 
pressure drop in these lines. The dimensions of the safety line and expansion line shall be proved by suitable means. 
 The expansion line and the safety line shall be connected and laid in such a way that any accumulation of 
dirt, scale or similar impurities are avoided. 
  PUBLIC REVIEW DRAFT, SEPTEMBER 2008KS 1855-1:2008 
© KEBS 2008 — All rights reserved 9 6.4.3 Blow-off lines 
 
The blow-off lines shall be laid in such a way that they cannot freeze up and that no water can accumulate 
within these lines. The orifices of the blow-off lines shall be arranged in such a way that any steam or heat 
transfer medium issuing from the safety valves does not cause any risk for people, materials or environment. 
 6.4.4 Store shut-off valve 
 Stores of large custom built systems with a volume of more than 20 m
3 shall be fitted with shut-off valves or 
other suitable devices to stop unintentional outflow of the store content in cases of system hazards. 
 
6.4.5 Indicators 
 
6.4.5.1 Indicators for collector loop flow 
 
The system should be fitted with any indicator for the collector loop flow. This can be either a flow rate 
indicator or two thermometers which indicate the actual flow and return temperatures of the collector loop.  
 
6.4.5.2 Pressure gauge 
 
For the indication of the actual overpressure, collect or loops which are filled under overpressure shall be 
fitted with a pressure gauge at a clearly visible spot of the installed system. The range of the working 
overpressure shall be marked. 
 
6.4.5.3 Heat meter 
 No requirements for small custom built systems.  
The collector loop of large custom built systems should be equipped with a heat meter. 
 
6.5 Installation 
 
If collectors are installed on the roofs of buildings, the tightness of the roof cover shall not be impaired. 
 The components which are exposed to the effects of weather shall be weathering resistant. They shall be 
designed, constructed and fastened in such a way that they are resistant to the following hazards:  
6.5.1 Lightning 
 
The system shall meet the requirements given in IEC 61024-1. 
 
NOTE In annex F of KS 1852-2 a revised version in respect of solar heating systems of the requirements in IEC 61024-1 is given.  
 
6.5.2 Wind loads 
 
If parts of the system are installed outdoors, they shall be resistant to wind loads according to ISO 6612. The 
manufacturer shall state the maximum values for vm (mean wind velocity) according to ISO 6612. The system 
may only be installed at locations, where the values of vm determined according to ISO 6612 are lower than 
the maximum values stated by the manufacturer. This shall be mentioned in the documents for the installer 
(see also 6.7.2). 
 
6.6 Initial operation and commissioning 
 
No requirements for small custom built systems. 
 
Before initial operation of a large custom built system it shall be ensured that: 
 PUBLIC REVIEW DRAFT, SEPTEMBER 2008KS 1855-1:2008 
10 © KEBS 2008 — All rights reserved ⎯ the installed system complies with the requirements of this standard. 
 
⎯ corresponding fittings are adjusted and the adjustments are recorded. 
 
⎯ the supervisor of the system, if there is one, is instructed. 
 
Large systems should be tested as specified in Annex C of KS 1855-2 and monitored as specified in Annex D of KS 1855-2. 
 
NOTE The procedures described in Annexes C and D of KS 1855-2 are optional. 
 
6.7 Documentation 
 
The documentation of the system as described below shall be complete and understandable.  
For small systems a technical documentation describing the assortment proposed by the company having 
established the file according to 6.7.1 should be available. A documentation according to 6.7.2 shall be 
provided with each system. 
 For large systems the full documentation of the system according to 6.7.3 shall be provided. 
 6.7.1 Assortment file for small systems 
 
The documentation describing an assortment of small systems should include the following information: 
 a) All proposed system configurations including related hydraulic and control schemes and specifications to 
enable the user to understand the operating mode of the system. 
 
b) A list of all components to be included into the above system configurations, with full reference to 
dimension and type. The identification of the listed components shall be easy and unambiguous. 
 c) A reference to all required component test reports according to 6.8. 
 d) A list of proposed combinations of dimension options within each system configuration. 
 e) Diagrams or tables stating the system performance under reference conditions for each proposed 
combination of dimension options within each system configuration. The reference conditions should be completely specified including the assumptions made on heat load(s) and weather data; the heat load(s) assumed should cover the range between 0.5 and 1.5 times the design load specified by the 
manufacturer. 
 
6.7.2 Documentation for small systems 
 
All components of each small custom built system shall be provided with a set of understandable assembly and operating instructions as well as service recommendations. This documentation shall include all 
instructions necessary for assembly, installation, operation and maintenance. These instructions shall include 
all information as listed in 4.6 of KS 1852-1. 
 
The documents shall be kept at a visible place (preferably nearby the store), protected from heat, water and dust. 
 
6.7.3 Documentation for large systems 
 Each large custom built system shall be provided with a set of assembly and operating instructions as well as 
service recommendations. This documentation shall include all instructions necessary for assembly, 
installation, operation and maintenance and all records of initial operation and commissioning according to 6.6. PUBLIC REVIEW DRAFT, SEPTEMBER 2008KS 1855-1:2008 
© KEBS 2008 — All rights reserved 11  
The documents shall be kept at a visible place (preferably nearby the store), protected from heat, water and 
dust. 
 
6.7.3.1 Documents in respect of dimensioning 
 The documentation should include: 
 
a) All load assumptions made (offering a set of values in a range spanning ± 30 % around the selected 
average load); 
 b) A full reference to the weather data used;  
c) A full record of the dimensioning method used for collector area, store device(s) and heat exchanger 
including all assumptions (e. g. the desired solar fraction) and the full reference to any simulation 
programme used; 
 d) A full record of the procedures used for hydraulic dimensioning of the collector loop and its components; 
 
e) A full record of the procedures used for the prediction of the system thermal performance including the 
full reference to any simulation programme used. 
 
6.7.3.2 Documents for assembly and installation 
 
The documents shall comply with a), e) to h), j) and k) of 4.6.1 in KS 1852-1.  
The description of assembly and installation of the system shall enable a proper installation in accordance with the system drawings. 
 6.7.3.3 Documents for operation 
 
The documentation shall comply with in paragraphs a), f) and g) of 4.6.2 of KS 1852-1. 
 The documents shall also include: 
 
a) Hydraulic and electrical schemes of the system;  
b) Description of the safety system with reference to location and adjustment of the safety components;  
NOTE Guidance should be given for a check of the system before taking it into operation again after one or more safety valves 
released. 
 
c) Intended action in the case of system failure or  hazard which is specified in the safety concept; 
 
d) Description of the control concept and the control system including the location of the control components 
(e.g. sensors). The control components should be included in the hydraulic scheme of the system; 
 
e) Maintenance instruction including start-up and shut-down of the system; 
 
f) Check on function and performance.  
6.8 System performance 
 
Small systems should be performance tested as described in KS 1855-2. The test results should be listed in 
a test report in accordance with Clause 8 of KS 1855-2. 
 
No requirements for large custom built systems.