oSIST prEN ISO 29464:2023
(Main)Cleaning of air and other gases - Terminology (ISO/DIS 29464:2023)
Cleaning of air and other gases - Terminology (ISO/DIS 29464:2023)
ISO 29464:2017 establishes a terminology for the air filtration industry and comprises terms and definitions only.
ISO 29464:2017 is applicable to particulate and gas phase air filters and air cleaners used for the general ventilation of inhabited enclosed spaces. It is also applicable to air inlet filters for static or seaborne rotary machines and UV-C germicidal devices.
It is not applicable to cabin filters for road vehicles or air inlet filters for mobile internal combustion engines for which separate arrangements exist. Dust separators for the purpose of air pollution control are also excluded.
Reinigung von Luft und anderen Gasen - Terminologie (ISO/DIS 29464:2023)
Dieses Dokument legt die Terminologie für die Luftfilterindustrie fest und enthält lediglich Begriffe und Definitionen.
Dieses Dokument gilt für Partikel- und Gasphasen-Luftfilter sowie Luftreiniger für die allgemeine Belüftung bewohnter umschlossener Räume. Darüber hinaus gilt das Dokument für Luftansaugfilter von stationären oder im Offshore-Bereich installierten Turbinen und Verdichtern sowie UV-C-Entkeimungseinrichtungen.
Das Dokument gilt nicht für Kabinenfilter für Straßenfahrzeuge oder Lufteinlassfilter für mobile Innenraum-Verbrennungsmotoren, für die separate Vorschriften bestehen. Staubabscheider zur Minderung der Luftverschmutzung sind ebenfalls ausgeschlossen.
Épuration de l'air et autres gaz - Terminologie (ISO/DIS 29464:2023)
ISO 29464:2017 établit une terminologie destinée aux industries de la filtration de l'air et comprend uniquement des termes et des définitions.
ISO 29464:2017 s'applique aux épurateurs et filtres d'air pour particules et phases gazeuses utilisés pour la ventilation générale des espaces clos habités. Elle s'applique également aux filtres d'admission d'air destinés aux machines rotatives statiques ou maritimes, ainsi qu'aux dispositifs germicides UV-C.
Elle ne s'applique ni aux filtres de cabine de véhicules routiers, ni aux filtres d'admission d'air de moteurs mobiles à combustion interne qui font l'objet de dispositions différentes. Les séparateurs de poussière employés pour le contrôle de la pollution de l'air sont également exclus.
Čiščenje zraka in drugih plinov - Terminologija (ISO/DIS 29464:2023)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
oSIST prEN ISO 29464:2023
01-julij-2023
Čiščenje zraka in drugih plinov - Terminologija (ISO/DIS 29464:2023)
Cleaning of air and other gases - Terminology (ISO/DIS 29464:2023)
Reinigung von Luft und anderen Gasen - Terminologie (ISO/DIS 29464:2023)
Épuration de l'air et autres gaz - Terminologie (ISO/DIS 29464:2023)
Ta slovenski standard je istoveten z: prEN ISO 29464
ICS:
01.040.13 Okolje. Varovanje zdravja. Environment. Health
Varnost (Slovarji) protection. Safety
(Vocabularies)
13.040.99 Drugi standardi v zvezi s Other standards related to air
kakovostjo zraka quality
23.120 Zračniki. Vetrniki. Klimatske Ventilators. Fans. Air-
naprave conditioners
oSIST prEN ISO 29464:2023 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN ISO 29464:2023
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oSIST prEN ISO 29464:2023
DRAFT INTERNATIONAL STANDARD
ISO/DIS 29464
ISO/TC 142 Secretariat: UNI
Voting begins on: Voting terminates on:
2023-04-27 2023-07-20
Cleaning of air and other gases — Terminology
Épuration de l'air et autres ga — Terminologie
ICS: 91.140.30; 01.040.91
This document is circulated as received from the committee secretariat.
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
ISO/CEN PARALLEL PROCESSING
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
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STANDARDS MAY ON OCCASION HAVE TO
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WHICH REFERENCE MAY BE MADE IN
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NATIONAL REGULATIONS.
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NOTIFICATION OF ANY RELEVANT PATENT
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PROVIDE SUPPORTING DOCUMENTATION. © ISO 2023
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oSIST prEN ISO 29464:2023
ISO/DIS 29464:2023(E)
DRAFT INTERNATIONAL STANDARD
ISO/DIS 29464
ISO/TC 142 Secretariat: UNI
Voting begins on: Voting terminates on:
Cleaning of air and other gases — Terminology
Épuration de l'air et autres ga — Terminologie
ICS: 91.140.30; 01.040.91
This document is circulated as received from the committee secretariat.
COPYRIGHT PROTECTED DOCUMENT
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© ISO 2023
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IN ADDITION TO THEIR EVALUATION AS
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NATIONAL REGULATIONS.
Website: www.iso.org ISO/DIS 29464:2023(E)
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PROVIDE SUPPORTING DOCUMENTATION. © ISO 2023
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oSIST prEN ISO 29464:2023
ISO/DIS 29464:2023(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 General, applicable to both particle and gas-phase air cleaners . 1
3.2 Particulate matter filters (including general ventilation, EPA, HEPA and ULPA
filters) . 6
3.3 Air intake particle filters for rotary machines . 22
3.4 Cleanable particle filter degradation . 23
3.5 Gas phase air cleaners (GPAC) . 25
3.6 UVC devices . 33
3.7 Stand-alone electrically-powered air cleaners . 37
Bibliography .39
Index .41
iii
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oSIST prEN ISO 29464:2023
ISO/DIS 29464:2023(E)
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 of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 142, Cleaning Equipment for air and other
gases.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
This third edition of ISO 29464 cancels and replaces the second edition (ISO 29464:2017), which has
been technically revised.
iv
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oSIST prEN ISO 29464:2023
DRAFT INTERNATIONAL STANDARD ISO/DIS 29464:2023(E)
Cleaning of air and other gases — Terminology
1 Scope
This document establishes a terminology for the air filtration industry and comprises terms and
definitions only.
This document is applicable to particulate matter and gas phase air filters and air cleaners used for
the general ventilation of inhabited enclosed spaces. It is also applicable to air inlet filters for static or
seaborne rotary machines and UV-C germicidal devices.
It is not applicable to cabin filters for road vehicles or air inlet filters for mobile internal combustion
engines for which separate arrangements exist. Dust separators for the purpose of air pollution control
are also excluded.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purpose of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at https:// www .electropedia .org/
— ISO Online browsing platform: available at https:// www .iso .org/ obp
3.1 General, applicable to both particle and gas-phase air cleaners
3.1.1
air cleaner
device for removing contaminants (3.1.12) from air in a ventilation system, building or other enclosed
space
3.1.2
robotic air cleaner
air cleaner that operates and changes its physical location autonomously without user intervention
Note 1 to entry: The robotic air cleaner can consist of a part that houses the air cleaning function and can have
a docking station and/or other accessories to assist its operation.
[SOURCE: IEC 63086-1:2020]
3.1.3
fresh-air air cleaner
air cleaner connected to the external environment, which provides pollutant-reduced outdoor air into
an indoor space
Note 1 to entry: The fresh-air air cleaner can also include other auxiliary functions, such as heat exchange.
[SOURCE: IEC 63086-1:2020]
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oSIST prEN ISO 29464:2023
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3.1.4
air velocity
rate of air movement
Note 1 to entry: It is expressed in m/s (fpm).
3.1.5
bypass
air cleaner bypass
sneakage
proportion of the challenge air stream (3.5.13) that passes around or through an air cleaner (3.1.1)
without interacting with the air cleaner
3.1.6
calibrate
to compare readings from the instrument to be calibrated with those from a reference device
3.1.7
capture
removal of contaminants from an air stream
3.1.8
classification
allocation of air cleaners into groups and classes according to relevant aspects of their air cleaning
performance
3.1.9
clean side
downstream side of an air cleaner element
[SOURCE: ISO 22031:2021]
3.1.10
combination product
air cleaner that includes a secondary function besides air cleaning within the same housing, such as
humidifying, dehumidifying, heating, or air conditioning
[SOURCE: IEC 63086-1:2020]
3.1.11
concentration
quantity of one substance dispersed in a defined amount of another
3.1.12
contaminant
pollutant
substance (solid, liquid or gas) that negatively affects the intended use of a gas
3.1.13
contamination
pollution
presence of a substance that negatively affects the intended use of a gas
3.1.14
decontamination factor
ratio of the contaminant (3.1.12) concentration or particle number upstream of an air cleaner to the
contaminant concentration (3.1.11) or particle number downstream of the air cleaner
Note 1 to entry: The decontamination factor can also be expressed as 1/(1 – overall efficiency) or as 1/penetration.
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3.1.15
dirty side
upstream side of an air cleaner element
[SOURCE: ISO 22031:2021]
3.1.16
downstream
area or region into which air flows on leaving an air cleaner
3.1.17
removal efficiency
air cleaner removal efficiency
filter removal efficiency
fraction or percentage of a challenge contaminant (3.1.12) that is removed by an air cleaner
3.1.18
average removal efficiency
value of removal efficiency which results from averaging the removal efficiencies determined over a
number of discrete intervals up to the end of an efficiency test
3.1.19
effluent
gas or liquid discharged from a given source into the external environment
Note 1 to entry: This is a general term describing any gas or liquid discharged from a given source; in this context,
the discharged liquid or gas may contain associated gaseous, liquid and/or particulate contaminants (3.1.12).
3.1.20
face velocity
filter face velocity
air cleaner face velocity
volumetric air flow rate divided by the nominal air cleaner face area (3.1.23)
Note 1 to entry: air cleaner face velocity is expressed in m/s (fpm).
3.1.21
filter
air filter
device for separating solid or liquid particles or gaseous contaminant (3.1.12) from an air stream
passing through the device
Note 1 to entry: The device is generally formed of a layer or layers of porous, fibrous or granular material.
Note 2 to entry: Air being cleaned by a filter must pass through the filter, whereas an air cleaner (3.1.1) can
reduce air contamination (3.1.13) by any method.
3.1.22
filter face area
air cleaner face area
cross-sectional face area of the air cleaner through which air flows into the device calculated using
exact dimensions
3.1.23
nominal filter face area
nominal air cleaner face area
cross-sectional face area of the air cleaner through which air flows into the device calculated using
dimensions rounded up to the nearest integer
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oSIST prEN ISO 29464:2023
ISO/DIS 29464:2023(E)
3.1.24
filter insert
replaceable part of a filter which contains the filter medium but which can only operate mounted inside
a frame
3.1.25
filter medium
material separating contaminants from air and characterized by its separating structure and its
structural and/or textile-technological characteristics
3.1.26
filter medium area
area of filter medium (3.1.25) contained in the filter
Note 1 to entry: For filters with pleats or folds, the filter medium area may be much larger than the filter face area
(3.1.22).
3.1.27
effective filter medium area
effective filtering area
exposed filter area
area of the filter medium (3.1.25) contained in the filter through which air passes during operation
Note 1 to entry: This excludes areas covered by sealant, spacers, struts, etc.
2 2
Note 2 to entry: Effective filter medium area is expressed in m (ft ).
3.1.28
filter medium velocity
media velocity
medium velocity
volumetric air flow rate divided by the effective filter medium area (3.1.27) of the filter
Note 1 to entry: Filter medium velocity is expressed in m/s (fpm).
Note 2 to entry: In devices where the filter medium surface area has been increased by use of pleats, folds or
bags, the filter medium velocity may be much less than the filter face velocity (3.1.20).
3.1.29
flow rate
air flow rate
volume of air flowing through an air cleaner per unit time
3.1.30
design flow rate
design air flow rate
air flow rate specified by the manufacturer
3.1.31
user air flow rate
user volume air flow rate
volume air flow rate specified by the user, at which an air cleaner is used or tested in situ
Note 1 to entry: This flow rate may be different from the one specified by the manufacturer.
[SOURCE: ISO 16170:2016]
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oSIST prEN ISO 29464:2023
ISO/DIS 29464:2023(E)
3.1.32
air flow rate, test
test air flow rate
test flow
test flow rate
test volume flow rate
air flow rate used for testing
3
Note 1 to entry: The flow rate is usually expressed in volumetric units (m /h (cfm)).
Note 2 to entry: Test flow rate may differ from the manufacturer’s specified flow through the air cleaner.
3.1.33
rated flow
flow rate through an air cleaner, either as stated by the manufacturer for defined conditions of use or as
agreed between the interested parties for a particular installation
Note 1 to entry: The manufacturer’s rated flow may differ from the test air flow rate (3.1.32).
3.1.34
gas
substance whose vapour pressure is greater than the ambient pressure (3.5.52) at ambient temperature
3.1.35
header frame
integral rigid frame of an air cleaner with a flange extending beyond the dimensions of the frame walls,
enabling it to be fastened and sealed against the holding frame (3.1.36)
3.1.36
holding frame
rigid structural frame, part of an air handling system into which an air cleaner is fastened and sealed
3.1.37
housing
device used to hold an air cleaner
3.1.38
hood
inlet device for an air extraction system
3.1.39
integrity test
in-situ test procedure for quantifying the unfiltered leakage of the system
[SOURCE: ISO 16170:2016]
3.1.40
leak
point in a filter at which the local penetration exceeds a given value
3.1.41
penetration
breakthrough
ratio of contaminant concentration downstream of an air cleaner to the upstream (challenge)
concentration (3.1.11)
Note 1 to entry: Sometimes expressed as a percentage.
Note 2 to entry: Penetration (P) is related to removal efficiency (E) by the expression: E = (1 – P) × 100 %.
Note 3 to entry: Penetration is related to the decontamination factor (DF) (3.1.14) by the expression: DF = 1/
penetration.
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oSIST prEN ISO 29464:2023
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3.1.42
reference device
primary device possessing accurately known parameters used as a standard for calibrating secondary
devices
Note 1 to entry: Reference particle filters are laboratory tested for removal efficiency by particle size (3.2.142)
and/or resistance to air flow.
3.1.43
resistance to air flow
differential pressure
pressure differential
pressure drop
difference in absolute (static) pressure between two points in an air flow system
Note 1 to entry: Resistance to air flow is expressed in Pa (inches of water).
3.1.44
test air
air being used for testing purposes
3.1.45
test device
device under test
DUT
air cleaner that is being subjected to performance testing
3.1.46
upstream
area or region from which air flows as it enters an air cleaner
3.1.47
washer
dust separator (3.2.153), droplet separator (3.2.152) or gas purifier (3.5.40) that depends on a liquid
acting as a collecting medium for its operation
3.2 Particulate matter filters (including general ventilation, EPA, HEPA and ULPA
filters)
3.2.1
aerosol
solid or liquid particles suspended in a gas
Note 1 to entry: Based on EU and EPA information, atmospheric aerosol is divided into four size categories: the
ultrafine range x < 0,1 µm, the fine range 0,1 µm ≤ x ≤ 2,5 µm, the coarse range 2,5 µm < x ≤ 10 µm, and the large
coarse range x > 10 µm, whereby x is the particle diameter (3.2.107).
3.2.2
liquid phase aerosol
liquid particles suspended in a gas
3.2.3
monodisperse aerosol
aerosol, the width of whose distribution function, described by the geometric standard deviation σg, is
less than 1,15 µm
3.2.4
aerosol neutralisation
action of bringing the aerosol to a Boltzmann charge equilibrium distribution with bipolar ions
Note 1 to entry: Neutralization should not be confused with discharging.
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oSIST prEN ISO 29464:2023
ISO/DIS 29464:2023(E)
3.2.5
aerosol photometer
instrument that measures the light-scattering properties of an aerosol sample
3.2.6
polydisperse aerosol
aerosol, the width of whose distribution function, described by the geometric standard deviation σg,
exceeds 1,5 µm
3.2.7
quasi-monodisperse aerosol
aerosol, the width of whose distribution function, described by the geometric standard deviation σg, is
between 1,15 µm and 1,5 µm
3.2.8
reference aerosol
defined approved aerosol for test measurement within a specific size range
3.2.9
solid phase aerosol
solid particles suspended in a gas
3.2.10
test aerosol
aerosol used for determining the particle removal efficiency performance of the device being tested or
for calibrating particle measurement devices
3.2.11
agglomerate
collection of solid particles adhering to each other
3.2.12
agglomeration
action leading to the formation of agglomerates (3.2.11)
3.2.13
agglutination
action of joining, by impact (3.2.86), solid particles coated with a thin adhesive layer or of trapping solid
particles by impact on a surface coated with adhesive
3.2.14
aggregate
relatively stable assembly of dry particles, formed under the influence of physical forces
3.2.15
arrestance
gravimetric arrestance
measure of the ability of a filter to remove a standard test dust from the air passing through it under
given operating conditions
Note 1 to entry: This measure is expressed as a mass percentage.
3.2.16
average arrestance
average gravimetric arrestance
ratio of the total mass of a standard test dust retained by the filter to the total mass of dust fed up to
final test pressure differential
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ISO/DIS 29464:2023(E)
3.2.17
initial arrestance
initial gravimetric arrestance
ratio of the mass of a standard test dust retained by the filter to the mass of dust fed after the first
increment of dust load
Note 1 to entry: This measure is expressed as a mass percentage.
Note 2 to entry: For example, in ISO 29461-1 or ISO 16890-3 procedure.
3.2.18
ash
solid residue of effectively complete combustion
3.2.19
fly ash
ash entrained by combustion gases
3.2.20
bioaerosol
particles of biological origin with an aerodynamic diameter of up to 100 μm suspended in a gaseous
medium
Note 1 to entry: Bioaerosol particles include viruses, bacteria, fungi, pollen, plant debris, fragments of these and
their derivatives such as endotoxins, glucans, allergens and mycotoxins.
3.2.21
burst pressure
value of differential pressure across a filter, above which damage/destruction of the filter medium
(3.1.20) or the structure occurs
3.2.22
calibration particle
mono-disperse spherical particle with a known mean particle size, e.g. polystyrene latex (PSL) particle
traceable to an international standard of length where the standard uncertainty of the mean particle
size is equal to or less than ±2,5 %
Note 1 to entry: The refractive index of (PSL) calibration particles is close to 1,59 at a wavelength of 589 nm
(sodium D line).
3.2.23
dust holding capacity
DHC
dust loading capacity
test dust capacity
TDC
total mass of loading dust captured by an air-cleaning device up to the final test resistance to air flow
3.2.24
cleaning
removal of the deposit of solid or liquid particles which has produced clogging
3.2.25
clogging
deposition, progressive or otherwise, of solid or liquid particles on or within a filter medium (3.1.25),
causing the flow to be obstructed
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ISO/DIS 29464:2023(E)
3.2.26
coagulation losses
particle losses due to collision and adhesion of particles
Note 1 to entry: Coagulation affects the measured particle parameters as follows: the particle number
concentration (3.2.114) decreases, the particle mass concentration (3.1.11) remains the same and the particle size
(3.2.118) increases.
3.2.27
coalescence
action by which liquid particles in suspension (3.2.156) unite to form larger particles
3.2.28
coefficient of variation
CV
standard deviation of a group of measurements divided by the mean
3.2.29
coincidence error
error which occurs because at a given time more than one particle is contained in the measurement
volume of a particle counter
Note 1 to entry: The coincidence error leads to a measured number concentration (3.1.11) which is too low and a
value for the particle diameter (3.2.107) which is too high.
3.2.30
correlation ratio
measure of bias between the upstream and downstream sampling systems
Note 1 to entry: This is expressed as the downstream particle concentration divided by the upstream particle
concentration measured without filter in place.
3.2.31
counting efficiency
ratio of detected number concentration (3.1.11) of particles to the real number concentration of particles
in a given size or range of sizes
Note 1 to entry: This is usually expressed as a percentage
Note 2 to entry: The counting efficiency depends on the particle size (3.2.118) and decreases progressively in the
proximity of the lower detection limit of the particle counter.
3.2.32
counting rate
number of counting events per unit time
3.2.33
cyclone
dust separator (3.2.153) or droplet separator (3.2.152) utilizing essentially the centrifugal force derived
from the motion of the gas
3.2.34
DiEthylHexylSebacate
DEHS
liquid used for generating the DEHS test aerosol (3.2.10)
3.2.35
equivalent diameter
diameter of a spherical particle which will give behaviour equivalent to that of the particle being
examined
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3.2.36
median diameter
diameter of the particle for which the cumulated volume fraction is equal to 50 % on a cumulated
volume particle size distribution curve
3.2.37
count median diameter
number median diameter
CMD
50th percentile of the number distribution of an aerosol
Note 1 to entry: 50 % of the particles are smaller than the count median diameter and 50 % are larger than the
count median diameter.
3.2.38
diluter
dilution system
system for reducing the sampled concentration (3.1.11) to avoid coincidence error in the particle counter
3.2.39
dispersion
operation as a result of which solid particles or liquid particles are distributed in a gas
Note 1 to entry: Also applied to a two-Phase System in which one phase, known as the “disperse phase”, is
distributed throughout the other, known as the “continuous medium”. For example, Dioctyl phthalate (DOP)
liquid or liquids with similar physical properties, are dispersed in air to generate a test aerosol (3.2.10).
3.2.40
D.O.P.
dispersed oil particles
3.2.41
DOP
dioctyl phthalate
3.2.42
droplet
liquid particle of small mass, capable of remaining in suspension (3.2.156) in a gas
Note 1 to entry: In some turbulent systems, for example clouds, its diameter can reach 200 μm.
3.2.43
dust
airborne solid particles which settle by gravity in calm conditions
3.2.44
dust control
whole of the processes for the separation of solid particles from a gas stream in which they are
suspended
Note 1 to entry: By extension, also the activities involved in the construction and commissioning of a dust
separator (3.2.153).
3.2.45
dust feeder
device which is used to distribute test dust to the filter
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© ISO 2023 – All rights reserved
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oSIST prEN ISO 29464:2023
ISO/DIS 29464:2023(E)
3.2.46
loading dust
synthetic test dust
synthetic dust formulated specifically for determination of the test dust capacity and arrestance of air
filters (3.1.21)
Note 1 to entry: A number of loading dusts are currently in use. Some of them are defined in ISO 15957:2015.
3.2.47
collection efficiency
ratio of the quantity of particles retained by a separator (3.2.151) to the quantity entering it with regard
to filters (3.1.21), dust separators (3.2.153) and droplet separators (3.2.152)
Note 1 to entry: This measure is normally expressed as a percentage.
3.2.48
elutriation
method of separating a mixture of particles according to their settling velocities within a gas
3.2.49
superficial face area
cross-sectional area of the filter element (3.2.60) through which the air flow passes
3.2.50
brush filter
air filter (3.1.21) in which the medium consists of a screen of intermeshing brushes
3.2.51
cartridge filter
compact filter often of cylindrical design
3.2.52
cellular filter
replaceable filter insert (3.1.24) which is or may be installed in a multiple bank or wall structure
Note 1 to entry: Examples of these are HEPA filters (3.2.67), rigid bags and panels.
3.2.53
ceramic filter
filter with a medium consisting of ceramic fibres or sintered porous ceramic
3.2.54
charged filter
electret filter
filter with an electrostatically charged medium
3.2.55
filter class
range of filtration performances clearly defined by lower and upper limit values
3.2.56
cleanable filter
filter designed to permit the removal of collected dust by application of an appropriate technique
3.2.57
coarse filter
filtration device with particle removal efficiency (3.5.54) < 50 % in
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