prEN ISO 6781-1
(Main)Performance of buildings - Detection of heat air and moisture irregulartites in buildings by infrared methods - Part 1 General Procedures
Performance of buildings - Detection of heat air and moisture irregulartites in buildings by infrared methods - Part 1 General Procedures
This part of ISO 6781 specifies the general procedures for thermography of residential, commercial and instituional / industrial buildings and superseds and replaces ISO 6781:1983.
The standard (Part1) provides up-to-date general procedures, guidelines and criteria covering the applicability of IRT techniques for builidngs, customer responsibilities, qualification of IRT personnel, equpiment requirments, IRT techniques, field and baseline measurement requirments for buildings, data collection, diagnosis and prognosis from results, safety considerations and test reports. Example thermograms of heat, air and moisture irregualrities are provided.
This standard (Part 1) is independent and stand-alone of all other parts of the 6781 standard. Other parts of the standard provide specific details for specific thermographic applications for practicioners.
Verhalten von Gebäuden - Feststellung von Heißluft- und Schimmelauffälligkeiten in Gebäuden anhand von Infrarotmethoden - Teil 1: Allgemeine Grundsätze
Dieses Dokument legt Anforderungen und Methoden für infrarot-thermographische Dienstleistungen für den Nachweis von wärme-, luft- und feuchtebezogene Unregelmäßigkeiten in Gebäude fest, die dem Anwender dabei helfen, (i) den Umfang der erforderlichen thermographischen Dienstleistungen, (ii) die Art und den Zustand der zu verwendenden Ausrüstung, (iii) die Qualifikationen der Ausrüstungsbetreiber, Bildanalytiker und Berichtsautoren sowie der Personen, die Empfehlungen aussprechen, (iv) die Anforderungen an die Berichterstattung über die Ergebnisse festzulegen und zu verstehen, und die ihm (v) einen Leitfaden an die Hand geben, wie die sich aus der Bereitstellung von thermographischen Dienstleistungen ergebenden Endergebnisse zu verstehen und zu nutzen sind.
Dieser Teil von ISO 6781 gilt für die allgemeinen Vorgehensweisen für infrarot-thermographische Verfahren, die auf Wohngebäude, Geschäftsgebäude und öffentliche & Spezialgebäude angewendet werden dürfen.
Performance des bâtiments - Détection d'irrégularités de chaleur, air et humidité dans les bâtiments par des méthodes infrarouges - Partie 1: Modes opératoires généraux
Značilnosti stavb - Zaznavanje nepravilnosti toplote, zraka in vlage v stavbah z infrardečimi metodami - 1. del: Splošni postopki (ISO/DIS 6781-1:2022)
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
oSIST prEN ISO 6781-1:2020
01-december-2020
Toplotne značilnosti stavb - Kvalitativno zaznavanje toplotnih nepravilnosti v
ovoju zgradbe - Infrardeča metoda (ISO/DIS 6781:2020)
Thermal performance of buildings - Qualitative detection of thermal irregularities in
building envelopes - Infrared method (ISO/DIS 6781:2020)
Wärmetechnisches Verhalten von Gebäuden - Qualitativer von Gebäuden - Qualitativer
Nachweis von Wärmebrücken in Gebäudehüllen - Infrarot-Verfahren (ISO/DIS
6781:2020)
Performance thermique des bâtiments - Détection qualitative des irrégularités
thermiques sur les enveloppes de bâtiments - Méthode infrarouge (ISO/DIS 6781:2020)
Ta slovenski standard je istoveten z: prEN ISO 6781-1
ICS:
91.120.10 Toplotna izolacija stavb Thermal insulation of
buildings
oSIST prEN ISO 6781-1:2020 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN ISO 6781-1:2020
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oSIST prEN ISO 6781-1:2020
DRAFT INTERNATIONAL STANDARD
ISO/DIS 6781-1
ISO/TC 163/SC 1 Secretariat: DIN
Voting begins on: Voting terminates on:
2020-09-11 2020-12-04
Performance of buildings — Detection of heat, air and
moisture irregularities in buildings by infrared methods —
Part 1:
General procedures
ICS: 91.120.10
IMPORTANT — Please use this updated version dated 2020-09-18,
and discard any previous version of this DIS. Note that the project is
now being processed as ISO/CEN parallel processing.
THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 6781-1:2020(E)
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. ISO 2020
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oSIST prEN ISO 6781-1:2020
ISO/DIS 6781-1:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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oSIST prEN ISO 6781-1:2020
ISO/DIS 6781-1:2020(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 General terms . 2
3.2 Thermography terms. 4
3.3 Definitions used in thermography . 6
4 Symbols (and abbreviated terms) . 7
5 Example applications of use of thermography in building assessments .7
6 Customer preparation . 8
7 Qualification of personnel . 9
7.1 Personnel – General Guidance . 9
7.2 Application specific requirements .10
7.2.1 Residential and small buildings - qualification requirements .10
7.2.2 Commercial buildings - qualification requirements .10
7.2.3 Institutional / industrial buildings - qualification requirements .10
8 Equipment requirements for thermographic examination of residential,
commercial and institutional buildings .11
8.1 Equipment – General Requirements' .11
8.2 Equipment – Specific Requirements .11
8.3 Calibration and checking of equipment . .11
9 Safety .12
10 Thermography techniques .12
10.1 Comparative thermography . .12
10.1.1 General.12
10.1.2 Technique .13
10.2 Comparative qualitative thermography .13
10.3 Comparative quantitative thermography.13
10.3.1 Comparative quantitative thermography - Limitations .14
11 Non-contact infrared radiometry (spot radiometry) using infrared thermography
cameras .14
12 Air Leakage and mass transfer .14
12.1 Air leakage .14
12.2 Mass Transfer - Moisture .15
13 .15
13.1 Conductivity test method - Moisture detection .15
13.2 Capacitance test method - Moisture detection .15
13.3 Phase change test method - Moisture detection .16
14 Baseline measurements for building maintenance and condition monitoring .16
15 Data collection .16
16 Field measurements of reflected temperature and emissivity, and attenuating media .17
17 Comparative assessment criteria – severity .17
18 Diagnosis and prognosis .18
18.1 Survey intervals .18
18.2 Image interpretation .18
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18.3 Fault identification process .18
19 Test report .18
19.1 General information .18
19.2 Building-specific information .19
19.3 Qualitative Inspections .20
19.4 Quantitative Inspections .21
19.5 Reporting of unsafe conditions .21
Annex A (informative) Pro-forma safety rules and guidelines .22
Annex B (normative) Field measurements of reflected apparent temperature and emissivity .23
Annex C (informative) Examples of buildings heat, air and moisture faults, failures and
anomalies detected by infrared thermography (IRT) .27
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Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO's adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is Technical Committee ISO/TC 163, Thermal Performance
and Energy Use in the Built Environment, Subcommittee SC1, Test and measurement methods, Working
Group 15, Thermography of buildings and industrial installations.
ISO 6781-1 cancels and replaces the first edition of ISO 6781:1983 which was a single-part document.
ISO 6781 consists of the following parts, (some of which are presently in development as indicated)
under the general title Performance of buildings — Detection of heat, air and moisture irregularities in
buildings by infrared methods:
— Part 1: General procedures
— Part 2: Equipment requirements (Under development)
— Part 3: Qualifications of equipment operators, data analysts and report writers (Under development)
— Part 4: Conducting Thermographic Inspections and Reporting of Results - Residential and small
buildings (Under development)
— Part 5: Conducting Thermographic Inspections and Reporting of Results – Commercial Buildings (Under
development)
— Part 6: Conducting Thermographic Inspections and Reporting of Results – Institutional and special
purpose buildings (Under development)
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Introduction
Infrared building thermography provides a tool to qualitatively identify the presence of energy-
wasting defects and anomalies within building structures. These defects and anomalies can include,
for example, thermal insulation defects, moisture content, and / or unwanted air movement or leakage
within the building enclosure.
Building thermography is carried out by means of an infrared thermography camera, which produces
an image based on the apparent radiance temperature of the target surface area. The thermal radiation
(infrared radiation density) from the target area is converted by the infrared thermography camera to
produce a thermal image (thermogram). This image (thermogram) represents the relative intensity of
thermal radiation from different parts of the surface. The radiation intensity indicated by the image is
related directly to (i) the surface temperature and distribution, (ii) the characteristics of the surface,
(iii) the ambient conditions, and (iv) the sensor itself.
As a result, surface temperature distribution can be a key parameter for monitoring the performance of
building components, building enclosure and the diagnostics of problems. In use, via analysis of surface
temperature distributions, irregularities in the heat and moisture properties of building enclosures and
components, and air movement within the building enclosure, can be indicated. These irregularities
can be due to, for example, thermal insulation defects, moisture content, air leakage within components
or through assemblies, or incorrect installation of components which comprise the construction of the
building.
To realize its full utility as an initial qualitative screening technique, or in-depth diagnostic technique,
thermography must often be supported and/or validated by other methods. These methods include, but
are not limited to, infrared photosensitive tracer gas methods, fan pressurization of the building enclosure,
heat-flow meters, smoke diffusion, anemometry, moisture metres, relative humidity sensors, etc.
Infrared building thermography inspection methodologies can be used for either new-construction
quality control applications, or in existing buildings as ongoing condition monitoring for periodic or
specific building-condition reporting. The latter applications may be accompanied with visual fault
symptoms, while the former may not necessarily present symptoms via visual faults.
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oSIST prEN ISO 6781-1:2020
DRAFT INTERNATIONAL STANDARD ISO/DIS 6781-1:2020(E)
Performance of buildings — Detection of heat, air and
moisture irregularities in buildings by infrared methods —
Part 1:
General procedures
1 Scope
This document specifies requirements and methodologies for infrared thermographic services for
detection of heat, air and moisture irregularities in buildings that help users to specify and understand
(i) the extent of thermographic services required, (ii) the type and condition of equipment that must
be used, (iii) the qualifications of equipment operators, image analysts, and report authors and
those making recommendations (iv) the requirements for reporting results, and (v) have a guide to
understanding and utilizing the final results stemming from provision of the thermographic services
This part of ISO 6781 is applicable to the general procedures for infrared thermographic methods as
may be applied to residential, commercial, and institutional & special use buildings.
2 Normative references
The following documents, in whole or part, are indispensable for the application of this international
standard. For dated references, only the edition cited applies. For undated references, the latest
edition of the referenced document (including any amendments) applies. Member Bodies of ISO and IEC
maintain registers of currently valid International Standards.
ISO 6781-3, Performance of buildings — Detection of heat, air and moisture irregularities in buildings by
infrared methods — Part 3: Qualifications of equipment operators, data analysts and report writers
ISO/DIS 9972, Thermal performance of buildings — Determination of air permeability of buildings — Fan
pressurization method
ISO/FDIS 10878, Nondestructive testing – Infrared thermography – Vocabulary
ISO/FDIS 12569, Thermal performance of buildings and materials — Determination of specific airflow rate
in buildings — Tracer gas dilution method
ISO 9869-1, Thermal insulation — Building elements — In-situ measurement of thermal resistance and
thermal transmittance — Part 1: Heat flow meter method
ISO 7345, Thermal performance of buildings and building components — Physical quantities and definitions
ISO 9288, Thermal insulation — Heat transfer by radiation — Physical quantities and definitions
ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 9288 and the following apply:
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3.1 General terms
3.1.1
system
regularly interacting or interdependent group of associated entities (components, factors, members,
parts, etc) forming an integrated whole and delineated by its spatial and temporal boundaries
Note 1 to entry: One or more of the associated entities define the boundary of the system.
3.1.2
analysis
careful scrutiny of constituent parts of a system (3.1.1) in order to thoroughly understand the whole
3.1.3
function
functional purpose of the building, building component or building system (3.1.1)
Note 1 to entry: The function is the activity assigned to, required of, or expected of the system.
3.1.4
small / residential building
building meeting the parameters defined in local building codes as small / residential building and as
agreed with customer receiving thermographic services
3.1.5
parameter
numerical or other measurable factor forming one of a set that sets the conditions for measurement, or
defines the system and its operation
3.1.6
performance
behaviour, characteristics and efficiency of a building, building component or building system (3.1.1)
3.1.7
sign
characteristic parameter of a signal, which shows information about a state
3.1.8
symptom
perception, made by means of human observations and measurements (descriptors), which may
indicate the presence of one or more faults (3.1.12) with a certain probability
3.1.9
syndrome
group of signs (3.1.7) or symptoms (3.1.8) that collectively indicate or characterize an abnormal
condition
3.1.10
anomaly
something that deviates from what is standard, normal or expected, and irregularity or abnormality
(3.1.11) in a system (3.1.1)
3.1.11
abnormality
deviation from a standard condition
3.1.12
Irregularity
a condition which significantly departs from the operational norm
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3.1.13
fault
a condition that occurs when a building or one of its components or assemblies degrades or exhibits
abnormal behaviour, which may lead to the failure (3.1.14) to perform in accordance with its design intent.
Note 1 to entry: A fault may be the result of a failure, but can exist without a failure.
Note 2 to entry: Planned actions or lack of external resources are not a fault.
3.1.14
fault progression
characterization of the change in severity of a fault (3.1.12) over time
3.1.15
failure
termination of the ability of an item to perform a required function (3.1.4)
Note 1 to entry: Failure is an event as distinguished from fault (3.1.12), which is a state.
3.1.16
failure mode
effect by which a failure (3.1.14) is observed
3.1.17
diagnostics
examination of symptoms (3.1.8) and syndromes (3.1.9) to determine the nature of faults (3.1.12) or
failures (3.1.14) (i.e.: kind, situation, extent)
3.1.18
root cause
set of conditions and/or actions that occur at the beginning of a sequence of events and result in the
initiation of a failure mode (3.1.15)
3.1.19
root cause failure analysis - RCFA
after a failure, the logical systematic examination of an item, its construction, application and
documentation in order to identify the failure mode (3.1.15) and determine the failure mechanism and
its basic cause
Note 1 to entry: Root cause failure analysis is often used to provide a solution to chronic problems.
3.1.20
risk assessment
process of balancing risk with cost, schedule and other management considerations
Note 1 to entry: Risk assessment consists of identifying risks, assessing those risks, determining a course of
action and tracking the effectiveness of the decision.
3.1.21
prognostics
analysis of the symptoms of faults (3.1.12) to predict a future condition and remaining useful life
3.1.22
prognosis
result of the prognostics process
3.1.23
qualitative
relating to measuring, or measured by the quality of something, rather than its quantity
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3.1.24
quantitative
relating to measuring, or measured by the quantity of something, rather than its general qualities
3.2 Thermography terms
3.2.1
Infrared
IR
that portion of the electromagnetic spectrum extending from the red visible wavelength, 0,75 μm to 1 mm
Note 1 to entry: Because of instrument design and infrared transmission characteristics of the atmosphere, most
infrared measurements are made between 0,75 μm and 15 μm wavelengths.
3.2.2
thermography
representation of the temperature distribution of a surface , in a thermal image
3.2.3
Thermographic analysis
interpretation and determination of the casual mechanisms producing variations and irregularities in
the thermal image
3.2.4
quantitative thermographic examination
examination of whole buildings, structures or components using thermographic methods with the
objective of providing quantitative (3.1.22) output
Note 1 to entry: Reporting requirements for both qualitative and quantitative examinations are specified in
clause 19 of this document.
3.2.5
infrared thermography camera
IRT camera
instrument that collects the infrared radiant energy from a target surface and produces a monochrome
(black and white) or colour image, where the grey shades (monochrome) or colour hues are related to
the target surface apparent temperature
3.2.6
thermal image
image which is produced by an infrared thermography camera and which represents the apparent
radiance temperature distribution over the target surfaces
Note 1 to entry: Such images are sometimes called infrared thermograms.
3.2.7
Isotherm
enhancement feature applied to an image, which marks an interval of equal apparent
temperature
3.2.8
Isotherm
region on an IR display consisting of points, lines or areas having the same infrared
radiation density
3.2.9
isotherm image
output from a infrared thermography camera showing isotherms (3.2.7 & 3.2.8)
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3.2.10
ironbow image
image comprising a colour palette running from black through blue, magenta, orange, yellow to white
that creates best contrast, in particular in regard to edges and shapes
3.2.11
image processing
converting an image to digital form and enhancing the image to prepare it for computer or visual
analysis
Note 1 to entry: In the case of a thermal image or thermogram this could include temperature scaling, spot
temperature measurements, thermal profiles, image manipulation, subtraction and storage.
3.2.12
apparent temperature
uncompensated reading from an infrared thermography camera containing all radiation incident on
the detector, regardless of its source
3.2.13
attenuating media
windows, filters, atmospheres, external optics, materials or other media that attenuate the infrared
radiation emitted from a source
3.2.14
black body
ideal perfect emitter and absorber of thermal radiation at all wavelengths. The emissivity 3.2.14 of a
black body is 1… ε = 1
Note 1 to entry: This is described by Planck's law.
3.2.15
emissivity
ε
ratio of a target surface’s radiance to that of a black body at the same temperature and over the same
spectral Interval
3.2.16
total radiance
radiant heat flow rate divided by the solid angle around the direction ∆ and the projected area normal
to this direction.
Note 1 to entry: Radiance includes emitted radiation from a surface as well as reflected and transmitted radiation.
3.2.17
apparent radiance temperature
temperature determined from the measured total radiance
Note 1 to entry: This temperature is the equivalent black body temperature which would produce the same total
radiance.
3.2.18
reflectivity
ρ − the ratio of the total reflected energy from a surface to total incident energy on that surface
Note 1 to entry: ρ = 1 – ε - τ ; for a mirror,
...
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