SIST EN 16863:2023

SLOVENSKI STANDARD
01-november-2023
Toplotnoizolacijski proizvodi za stavbe - Tovarniško narejeni odsevni izolacijski
proizvodi (RI) - Specifikacija
Thermal insulation products for buildings - Factory made reflective insulation (RI)
products - Specification
Wärmedämmstoffe für Gebäude - Werkmäßig hergestellte reflektierende
Wärmedämmstoffe - Spezifikation
Produits isolants thermiques pour le bâtiment - Produits d'isolation réfléchissants
manufacturés - Spécification
Ta slovenski standard je istoveten z: EN 16863:2023
ICS:
91.100.60 Materiali za toplotno in Thermal and sound insulating
zvočno izolacijo materials
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 16863
EUROPEAN STANDARD
NORME EUROPÉENNE
June 2023
EUROPÄISCHE NORM
ICS 91.100.60
English Version
Thermal insulation products for buildings - Factory made
reflective insulation (RI) products - Specification
Produits isolants thermiques pour le bâtiment - Wärmedämmstoffe für Gebäude - Werkmäßig
Produits d'isolation réfléchissants manufacturés - hergestellte reflektierende Wärmedämmstoffe -
Spécification Spezifikation
This European Standard was approved by CEN on 17 April 2023.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

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, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 16863:2023 E
worldwide for CEN national Members.

Contents Page
European foreword . 6
Introduction . 7
1 Scope . 8
2 Normative references . 8
3 Terms, definitions, symbols, units and abbreviated terms .10
3.1 Terms and definitions .10
3.2 Symbols, units and abbreviated terms .12
4 Characteristics .13
4.1 Reaction to fire .13
4.2 Propensity to undergo continuous smouldering combustion .13
4.3 Water permeability .14
4.3.1 Short-term water absorption .14
4.3.2 Long term water absorption .14
4.3.3 Water penetration .14
4.4 Water vapour diffusion resistance .14
4.5 Micro-biological growth (for products containing vegetable or animal fibre layers) -
Mould and biological resistance .14
4.6 Release of dangerous substances to the indoor environment .14
4.7 Tensile strength parallel to faces .15
4.8 Resistance to tearing .15
4.9 Compressive resistance (only for load bearing application in floors) .15
4.10 Sound absorption index (only for sound insulation application) .15
4.11 Impact sound transmission index (only for sound insulation in floor application) .15
4.11.1 Dynamic stiffness .15
4.11.2 Compressibility .15
4.11.3 Air flow resistivity .15
4.12 Direct airborne sound insulation index (only for sound insulation application) .15
4.12.1 Air flow resistivity .15
4.12.2 Air flow permeability .16
4.13 Thermal resistance .16
4.13.1 Core thermal resistance .16
4.13.2 Emissivity .16
4.13.3 Thickness .16
4.14 Length .16
4.15 Width .17
4.16 Squareness (only for products supplied in form of board) .17
5 Testing, assessment and sampling methods .17
5.1 Test of reaction to fire .17
5.2 Test of continuous smouldering combustion .18
5.3 Test of water permeability .18
5.3.1 Short-term water absorption .18
5.3.2 Long-term water absorption .18
5.3.3 Water penetration .18
5.4 Water vapour transmission.18
5.5 Test of microbiological growth .18
5.5.1 General . 18
5.5.2 Mould and biological resistance . 19
5.6 Release of dangerous substances to the indoor environment . 19
5.7 Tensile strength parallel to faces . 19
5.8 Resistance to tearing . 19
5.9 Compressive resistance (for loadbearing application in floors) . 19
5.10 Sound absorption index . 19
5.11 Impact sound transmission index (only for application in floors) . 20
5.11.1 Dynamic stiffness . 20
5.11.2 Compressibility . 20
5.11.3 Air flow resistivity . 20
5.12 Direct airborne sound insulation index (only for acoustical application) . 20
5.12.1 Air flow resistivity . 20
5.12.2 Air flow permeability . 21
5.13 Thermal resistance . 21
5.13.1 Core thermal resistance . 21
5.13.2 Emissivity . 22
5.13.3 Thickness . 22
5.14 Length and tolerance . 22
5.15 Width and tolerance . 22
5.16 Squareness (only for product manufactured in board) . 23
5.17 Sampling . 23
5.17.1 General . 23
5.17.2 Conditioning . 23
5.17.3 Overview of testing conditions . 23
5.17.4 Test samples, testing and expression of results . 23
6 Assessment and verification of the constancy of performance (AVCP) . 25
6.1 General . 25
6.2 Product type determination . 25
6.3 Factory production control . 25
7 Marking and labelling . 26
Annex A (normative) Reaction to fire, products and assemblies . 27
A.1 General . 27
Annex B (normative) Determination of the declared value of thermal resistance of the core
and the declared value of emissivity . 31
B.1 Introduction . 31
B.2 Input data . 31
B.3 Declared values . 31
B.3.1 General . 31
B.3.2 Case where emissivity is declared . 31
B.3.3 Case where thermal resistance is declared . 32
Annex C (informative) Examples for the determination of thermal resistance and emissivity
................................................................................................................................................................... 34
C.1 Case for emissivity. 34
C.2 Case for core thermal resistance . 35
Annex D (informative) Determining the total thermal resistance including associated
airspace(s) .37
D.1 General .37
D.2 Calculation of thermal resistance including associated airspace(s) .37
D.3 Numerical example .38
Annex E (normative) Determination of thickness reduction level and required load of the
weighted plate to be used for thickness measurement .39
E.1 General .39
E.2 Definition .39
E.3 Determination of the thickness reduction level of a product .39
E.4 Thickness reduction level of the product and specification of the weighted plate for
thickness measurement according to EN ISO 29466:2022 .39
Annex F (informative) Installed thickness measurement .41
F.1 Purpose of this test protocol .41
F.2 Scope of the test method .41
F.3 Definitions .41
F.4 Principle of the test method .42
F.5 Reference installations .42
F.6 Apparatus .43
F.6.1 Wooden assembly .43
F.6.2 Measuring bench .43
F.6.3 Measuring lines .44
F.7 Test specimen preparation.45
F.8 Procedure.45
F.8.1 Testing procedure .45
F.8.2 Measuring procedure .45
F.8.3 Sample measuring sheet (manual measurement) .46
F.8.4 Calculation and expression of results .46
F.9 Uncertainty of the test method and the measuring apparatus .47
F.9.1 General .47
F.9.2 Case of manual measurements .47
F.9.3 Case of 3D measurement .48
F.10 Test report .48
Annex G (informative) Examples of placement: test sample into the wooden assembly .49
G.1 General .49
G.2 Step by step procedure of installation .49
Annex H (normative) Product type determination (PTD) and factory production control
(FPC) .54
H.1 General . 54
Bibliography . 58
European foreword
This document (EN 16863:2023) has been prepared by Technical Committee CEN/TC 88 “Thermal
insulating materials and products”, the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by December 2023, and conflicting national standards shall
be withdrawn at the latest by March 2025.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This standard is one of a series of standards for thermal insulation products used in buildings but this
standard can be used in other areas where appropriate. A list of all parts in a series can be found on the
CEN website.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: 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, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the United
Kingdom.
Introduction
Reflective insulation products are made from low emissive film(s) and infrared semi-transparent
material layer(s) called spacers; like waddings of synthetic or natural fibres, synthetic foam or plastic
filled with air bubbles.
Reflective (low emissivity at the appropriate wavelengths) surfaces are used to reduce the heat transfer
by thermal radiation. This may occur across the product itself when it includes air cavities or a material
that is wholly or partially transparent to infrared radiation, and/or across air gap(s) that are deliberately
created between the external reflective surface(s) of the product and the structure of the building
element.
1 Scope
This document is applicable to factory-made reflective insulation (RI) products intended for use as
thermal and acoustic insulation of buildings. The products are manufactured in the form of rolls or
boards. They are made from low emissive film(s) and infrared semi-transparent material layer(s) or air
cavities.
This document describes the methods and criteria for assessing the performance of factory-made
reflective insulation products in relation to essential product characteristics and includes the procedures
for assessment and verification of the constancy of performance.
Reflective insulation products require specific setup instruction(s) depending on their level of
compressibility.
This document does not specify the required level of a given property to be achieved by a product to
demonstrate fitness for purpose in a particular application. The levels required for a given application
can be found in regulations or non-conflicting standards.
This document does not cover:
— products intended to be used for the insulation of building equipment and industrial installations;
— products made of mineral wool, polystyrene or polyurethane foams (not inclusive) faced with
aluminium or metalized foil on one or both external surfaces (which are already covered by a
corresponding harmonized European product standard);
— membranes used as vapour control layer (VCL) or vapour-permeable roof or wall underlay (which
are already covered by a specific harmonized European product standard).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 824:2013, Thermal insulating products for building applications — Determination of squareness
EN 1928:2000, Flexible sheets for waterproofing — Bitumen, plastic and rubber sheets for roof
waterproofing — Determination of watertightness
EN 1931:2000, Flexible sheets for waterproofing — Bitumen, plastic and rubber sheets for roof
waterproofing — Determination of water vapour transmission properties
EN 12114:2000, Thermal performance of buildings — Air permeability of building components and building
elements — Laboratory test method
EN 12310-1:1999, Flexible sheets for waterproofing — Part 1: Bitumen sheets for waterproofing —
Determination of resistance to tearing (nail shank)
EN 12311-1:1999, Flexible sheets for waterproofing — Part 1: Bitumen sheets for roof waterproofing —
Determination of tensile properties
EN 13172:2012, Thermal insulation products — Evaluation of conformity
EN 13501-1:2018, Fire classification of construction products and building elements — Part 1:
Classification using data from reaction to fire tests
EN 13820:2003, Thermal insulating materials for building applications — Determination of organic
content
EN 13823:2020+A1:2022, Reaction to fire tests for building products — Building products excluding
floorings exposed to the thermal attack by a single burning item
EN 13859-1:2014, Flexible sheets for waterproofing — Definitions and characteristics of underlays —
Part 1: Underlays for discontinuous roofing
EN 15101-1:2013+A1:2019, Thermal insulation products for buildings — In-situ formed loose fill cellulose
(LFCI) products — Part 1: Specification for the products before installation
EN 15715:2009, Thermal insulation products — Instructions for mounting and fixing for reaction to fire
testing — Factory made products
EN 16012:2012+A1:2015, Thermal insulation for buildings — Reflective insulation products —
Determination of the declared thermal performance
EN 16516:2017+A1:2020, Construction products: Assessment of release of dangerous substances —
Determination of emissions into indoor air
EN 16733:2016, Reaction to fire tests for building products — Determination of a building product's
propensity to undergo continuous smouldering
EN 29052-1:1992, Acoustics — Determination of dynamic stiffness — Part 1: Materials used under floating
floors in dwellings
EN ISO 354:2003, Acoustics — Measurement of sound absorption in a reverberation room (ISO 354:2003)
EN ISO 1182:2020, Reaction to fire tests for products — Non-combustibility test (ISO 1182:2020)
EN ISO 1716:2018, Reaction to fire tests for products — Determination of the gross heat of combustion
(calorific value) (ISO 1716:2018)
EN ISO 9053-1:2018, Acoustics — Determination of airflow resistance — Part 1: Static airflow method
(ISO 9053-1:2018)
EN ISO 9229:2020, Thermal insulation — Vocabulary (ISO 9229:2020)
EN ISO 11654:1997, Acoustics — Sound absorbers for use in buildings — Rating of sound absorption
(ISO 11654:1997)
EN ISO 11925-2:2020, Reaction to fire tests — Ignitability of products subjected to direct impingement of
flame — Part 2: Single-flame source test (ISO 11925-2:2020)
EN ISO 12572:2016, Hygrothermal performance of building materials and products — Determination of
water vapour transmission properties — Cup method (ISO 12572:2016)
EN ISO 16535:2019, Thermal insulating products for building applications — Determination of long-term
water absorption by immersion (ISO 16535:2019)
EN ISO 29465:2022, Thermal insulating products for building applications — Determination of length and
width (ISO 29465:2022)
EN ISO 29466:2022, Thermal insulating products for building applications — Determination of thickness
(ISO 29466:2022)
EN ISO 29469:2022, Thermal insulating products for building applications — Determination of
compression behaviour (ISO 29469:2022)
EN ISO 29770:2022, Thermal insulating products for building applications — Determination of thickness
for floating-floor insulating products (ISO 29770:2022)
EN ISO 29767:2019, Thermal insulating products for building applications — Determination of short-term
water absorption by partial immersion (ISO 29767:2019)
3 Terms, definitions, symbols, units and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in EN ISO 9229:2020 (with the
exception of 3.7.15 and 3.7.16) and EN 16012:2012+A1:2015, and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
3.1.1
reflective insulation product
RI product
product made from low emissive film(s) incorporating infrared semi-transparent material layer(s)
and/or air cavities, of which there are three types (see Figure 1 to Figure 3)

Key
1 semi-transparent spacer
2 low emissive film
Figure 1 — Cellular reflective insulation comprising air cavities associated with low emissivity
surfaces
Key
1 semi-transparent spacer
2 low emissive film
Figure 2 — Bubble foil comprising external reflective film and one or more layers of plastic filled
with air bubbles, in single or several layers or separated by synthetic fibres, foam, quilt and/or
wadding
Key
1 semi-transparent spacer
2 low emissive film
Figure 3 — Multi-foils reflective insulation comprising internal reflective film(s) separated by
synthetic or natural fibres, foam, quilt, plastic filled with air bubbles and/or wadding that may
be faced with external reflective foil(s)
3.1.2
roll
flexible reflective insulation product, supplied rolled or flat
3.1.3
board
rigid or semi-rigid reflective insulation product of rectangular shape and cross section in which the
thickness is uniform and substantially smaller than the other dimensions
[SOURCE: EN ISO 9229:2020, 3.3.3, modified – Synonymous term and note have been omitted]
3.1.4
compressibility
measure of the relative volume change of a fluid or a solid as a response to a pressure change
3.1.5
core thermal resistance
thermal resistance of the product from face to face at the tested thickness, excluding the contribution of
any air space(s)/layer(s) adjacent to the product
3.1.6
emissivity
ratio of the energy radiated from a material’s surface to that radiated from a perfect emitter, known as a
blackbody, at the same temperature and wavelengths and under the same viewing conditions
3.2 Symbols, units and abbreviated terms
AF 2
airflow resistivity
r kPa⋅s/m
α 3 n
level of practical sound absorption coefficient
p m /(s⋅Pa )
α
level of weighted sound absorption coefficient -
w
b width mm
β* thickness difference (see thickness reduction level test in 4.13.3) mm
β thickness reduction (see 4.13.3) %
3 n
C airflow coefficient
m /(s⋅Pa )
CP level for compressibility -
CS(10\Y) declared level of compressive stress or compressive strength kPa
d thickness mm
d
thickness under a load of 2 kPa after removal of an additional load of 48 kPa mm
B
d
thickness of the product under 250 Pa mm
L
d
nominal thickness mm
N
d
thickness of the product under 3 Pa mm
3Pa
d
thickness of the product under 25 Pa mm
25Pa
ε emissivity of a surface -
ε
one test result of emissivity of a surface -
i
ε
mean of a number of test results of emissivity of a surface -
mean
ε
90 % fractile with a confidence level of 90 % for emissivity -
90/90
ε
declared value of emissivity -
D
k factor related to the number of test results -
λ
declared thermal conductivity for homogeneous products W/m∙K
D
l length mm
µ value for water vapour diffusion resistance factor -
n exponent related to air permeability -
n number of test results -
R 2
90 % fractile with a confidence level of 90 % for the thermal resistance
90/90 m ⋅K/W
R 2
declared core thermal resistance
D(core) m ⋅K/W
R 2
thermal resistance of the core
(core) m ⋅K/W
R 2
total thermal resistance with heat flow downward
(HFD) m ⋅K/W
R 2
total thermal resistance with horizontal heat flow
(HFH) m ⋅K/W
R 2
total thermal resistance with heat flow upwards
(HFU) m ⋅K/W
R 2
one test result of thermal resistance
i m ⋅K/W
R 2
mean of a number of test results for thermal resistance
mean m ⋅K/W
s' level of dynamic stiffness
MN/m
s
water vapour diffusion-equivalent air layer thickness m
d
s 2
estimate of the standard deviation of the thermal resistance
R m ⋅K/W
s
estimate of the standard deviation of emissivity -
ε
S
deviation from squareness on length and width -
b
S
deviation from squareness on thickness -
d
σ
tensile strength perpendicular to faces kPa
mt
σ
tensile strength parallel to faces kPa
t
W 2
long-term water absorption by partial immersion
lp kg/m
W 2
short-term water absorption
p kg/m
X
total thickness reduction at time t mm
t
Z water vapour resistance
m ⋅h⋅Pa/mg
4 Characteristics
4.1 Reaction to fire
The reaction to fire indicates the behaviour of the construction product in the event of fire. When tested
in accordance with the test methods given in 5.1, relevant for the claimed class, the test results shall be
expressed as a class in accordance with Annex A of this document and EN 13501-1:2018.
If a product(s) covered by this document has passed fire performance testing in accordance with the
appropriate EN test methods, the established assigned class shall apply to the product(s) without
carrying out further reaction to fire tests. If (a) product(s) covered by this document is/are made from
one or more of the materials belonging to the “No contribution to fire” category – having passed the
testing in accordance with the appropriate EN test methods – they need not be tested further.
4.2 Propensity to undergo continuous smouldering combustion
The continuous smouldering combustion is the propensity of products to undergo continuous
smouldering continuously when exposed to an open flame. When tested in accordance with 5.2, the
results are expressed either as:
— no propensity to undergo continuous smouldering, or
— propensity to undergo continuous smouldering, or
— assessment not possible.
4.3 Water permeability
4.3.1 Short-term water absorption
Short term water absorption indicates the behaviour of products when subject to a short period of
immersion in water. When tested in accordance with 5.3.1, results are expressed in kilograms per square
meter.
4.3.2 Long term water absorption
Long term water absorption indicates the behaviour of products when subject to a long period of
immersion in water. When tested in accordance with 5.3.2, results are expressed in kilograms per square
meter.
4.3.3 Water penetration
Water penetration indicates a product’s ability to prevent or limit the passage of water through it. When
tested in accordance with 5.3.3, the result is expressed as one of the “W” categories, as per Table 1.
Table 1 — Category of water penetration
Category Water penetration
W1 No water penetration
W2 Maximum 100 ml water passing through
W3 More than 100 ml water passing through

4.4 Water vapour diffusion resistance
Water vapour diffusion resistance indicates the resistance to water vapour diffusion.
When tested in accordance with 5.4, the property is expressed as the water vapour resistance, Z, or the
water vapour diffusion resistance factor, μ, or water vapour diffusion-equivalent air layer thickness, s .
d
All test results for Z, μ or s should be within the tolerance of the declared value.
d
4.5 Micro-biological growth (for products containing vegetable or animal fibre layers) -
Mould and biological resistance
Mould and biological resistance indicate the extent to which materials might be disintegrated by
microorganisms such as bacteria, algae or fungi. When tested in accordance with 5.5.2, results are
expressed either as:
— no propensity to promote the development of moulds if no mould is visible on the surface of the test
specimen under a microscope under reflected light with a magnification × 50; or
— propensity to favour the development of moulds in all cases other than the preceding; or
— evaluation not possible if less than 50 % of the surface of the comparison material is covered with
mould visible to the naked eye.
4.6 Release of dangerous substances to the indoor environment
Release of dangerous substances to the indoor environment refers to volatile organic compounds (VOCs),
which are organic chemicals with a high vapour pressure (resulting from a low boiling point) at ordinary
room temperature. This causes large numbers of molecules to evaporate or sublimate from the
compound and enter the surrounding air; a trait known as volatility. VOCs are numerous, varied, and
ubiquitous. When tested in accordance with 5.6, results are expressed as concentration in μg/m .
4.7 Tensile strength parallel to faces
A product’s tensile strength parallel to its faces in the longitudinal and transverse direction is tested in
accordance with 5.7.
4.8 Resistance to tearing
A product’s resistance to tearing indicates its ability to resist damage caused by exposed nails. When
tested in accordance with 5.8, results are expressed in N.
4.9 Compressive resistance (only for load bearing application in floors)
A product’s compressive resistance (CS) indicates the compression behaviour of test specimens as a
response to changes in pressure.
In the case of load bearing applications, it indicates the ability of the product to resist damage when
exposed to uniform compression loads. When tested in accordance with 5.9, results are expressed as:
— compressive strength and corresponding strain; or
— compressive stress at 10 % strain; or
— compression modulus of elasticity.
4.10 Sound absorption index (only for sound insulation application)
The sound absorption index indicates the coefficient of acoustic materials. When tested in accordance
with 5.10, results are expressed as a weighted sound absorption coefficient, α .
w
4.11 Impact sound transmission index (only for sound insulation in floor application)
4.11.1 Dynamic stiffness
Dynamic stiffness indicates the dynamic rigidity of material constituting resilient products and gives a
parameter by which to determine the acoustic insulation of products used in floor installations. When
tested in accordance with 5.11.1, the result, s, is expressed in level with steps of 1 MN/m .
4.11.2 Compressibility
Compressibility indicates the thickness of thermal insulating products for impact sound insulation. When
tested in accordance with 5.11.2, results are expressed as thickness d , d and d , in mm.
L F B
4.11.3 Air flow resistivity
Air flow resistivity indicates how easily air can enter a porous material and the resistance that the air
flow meets thorough the material. When tested in accordance with 5.11.3, results are expressed as AF
R
in levels with steps of 1 kPa⋅s/m .
4.12 Direct airborne sound insulation index (only for sound insulation application)
4.12.1 Air flow resistivity
See 4.11.3.
4.12.2 Air flow permeability
Air flow permeability indicates the behaviour of the product when subjected to positive or negative air
pressure differences. When tested in accordance with 5.12.2, results are expressed as coefficient C
3 n
expressed in m /(s⋅Pa ) and exponent n for appropriate pressure differences.
4.13 Thermal resistance
4.13.1 Core thermal resistance
The core thermal resistance gives the thermal behaviour of the product from face to face at the tested
thickness, excluding the contribution of any air space(s)/layer(s) adjacent to the product. When tested in
accordance with 5.13.1, results are expressed as R in m ·K/W, and declared in accordance with
(core)
Annex B. Examples of determination of the declared values of core thermal resistance, R , are given
D(core)
in Annex C.
NOTE Measurements with a guarded hot plate (METHOD A) or heat flow meter (METHOD B) permit a direct
determination of the core thermal resistance. When measured in a hot box, the core thermal resistance is deducted
from the total thermal resistance by removing the thermal performance of the two vertical low emissivity air gaps.
4.13.2 Emissivity
The emissivity is defined (see 3.1.6) as the ratio of the energy radiated from the tested material’s surface
relative to that radiated from a perfect emitter, known as a blackbody, at the same temperature and
wavelengths and under the same viewing conditions. When tested in accordance with 5.13.2, results are
expressed as ε, a dimensionless number between 0 (for a perfect reflector) and 1 (for a perfect emitter)
and declared in accordance with Annex B. Examples of determination of the declared values of emissivity,
ε , are given in Annex C.
D
NOTE 1 The thermal resistance of adjacent air spaces can be affected by ageing of the low emissive facing.
However, initial measurements already take into account the potential ageing of the low emissivity surface.
NOTE 2 Guidance and example calculations of the thermal resistance of air cavities are given in Annex D.
4.13.3 Thickness
Thickness is a proxy characteristic for thermal resistance which is based upon that thickness. The
thickness of the product is measured in accordance with 5.13.3, the result of the thickness is expressed
in mm.
Some kinds of reflective insulation products, defined as highly compressible, are unrealistically affected
by the weighted plate used for thickness measurement in that it can reduce the thickness of the product
to the extent that its core properties change. To prevent excessive stress during thickness measurements,
specific loads are specified for the weighted plate depending on the thickness reduction level (see
Annex E) of the reflective insulation product being tested.
The installed thickness of highly compressible insulations and those with non-flat surface geometries
depends on the method of installation. Annex F and Annex G describe a test method that allows a
determination of the maximum and the average installed thickness of such
...