ISO 29464:2011

Cleaning equipment for air and other gases — Terminology

ISO 29464:2011 establishes a terminology for the air filtration industry and comprises terms and definitions together with, in some cases, symbols and units. ISO 29464:2011 is applicable to both particulate and gas phase air filters and cleaners used for the general ventilation of inhabited enclosed spaces. Air inlet filters for static or seaborne rotary machines are included. ISO 29464:2011 does not apply 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.

Séparateurs aérauliques — Terminologie

General Information

• Status: Withdrawn
• Publication Date: 24-Aug-2011
• Withdrawal Date: 24-Aug-2011
• ICS: 01.040.91 - Construction materials and building (Vocabularies)
• ICS: 91.140.30 - Ventilation and air-conditioning systems
• Technical Committee: ISO/TC 142 - Cleaning equipment for air and other gases
• Drafting Committee: ISO/TC 142 - Cleaning equipment for air and other gases
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 28-Aug-2017

Relations

• Revised: ISO 29464:2017 - Cleaning of air and other gases — Terminology
• Effective Date: 22-Sep-2012
• Revises: ISO 3649:1980 - Cleaning equipment for air or other gases — Vocabulary
• Effective Date: 18-Jul-2009

Standards Content (Sample)

INTERNATIONAL ISO

STANDARD 29464

First edition
2011-09-01
Cleaning equipment for air and other
gases — Terminology
Séparateurs aérauliques — Terminologie




Reference number
ISO 29464:2011(E)

©
ISO 2011

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ISO 29464:2011(E)



COPYRIGHT PROTECTED DOCUMENT


©  ISO 2011
The reproduction of the terms and definitions contained in this International Standard is permitted in teaching manuals, instruction
booklets, technical publications and journals for strictly educational or implementation purposes. The conditions for such reproduction are:
that no modifications are made to the terms and definitions; that such reproduction is not permitted for dictionaries or similar publications
offered for sale; and that this International Standard is referenced as the source document.
With the sole exceptions noted above, no other part of this publication may be reproduced or utilized in any form or by any means,
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Published in Switzerland

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ISO 29464:2011(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 29464 was prepared by Technical Committee ISO/TC 142, Cleaning equipment for air and other gases.
This first edition of ISO 29464 cancels and replaces ISO 3649:1980, which has been technically revised.

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INTERNATIONAL STANDARD ISO 29464:2011(E)

Cleaning equipment for air and other gases — Terminology

1 Scope
This International Standard establishes a terminology for the air filtration industry and comprises terms and
definitions together with, in some cases, symbols and units.
This International Standard is applicable to both particulate and gas phase air filters and cleaners used for the
general ventilation of inhabited enclosed spaces. Air inlet filters for static or seaborne rotary machines are
included.
It does not apply 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
The following referenced documents are indispensable for the application 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.
ISO 29463-1, High-efficiency filters and filter media for removing particles in air — Part 1: Classification,
performance testing and marking
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1 Particulate filters
3.1.1
aerosol
system of solid or liquid particles suspended in gas
NOTE In general, one divides the atmospheric aerosol into three size categories: the ultrafine range x  0,1 µm, the fine
range 0,1 µm  x  1 µm and the coarse range x  1 µm, whereby x is the particle diameter.
3.1.2
monodisperse aerosol
aerosol, the width of whose distribution function, described by the geometric standard deviation g, is less
than 1,15 µm
3.1.3
polydisperse aerosol
aerosol, the width of whose distribution function, described by the geometric standard deviation g, exceeds
1,5 µm
3.1.4
quasi-monodisperse aerosol
aerosol, the width of whose distribution function, described by the geometric standard deviation g, lies
between 1,15 µm and 1,5 µm
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ISO 29464:2011(E)
3.1.5
test aerosol
aerosol used for determining filter performance and for calibrating particle measurement devices
3.1.6
agglomerate
collection of solid particles adhering to each other
3.1.7
agglomeration
action leading to the formation of agglomerates
3.1.8
agglutination
action of joining, by impact, solid particles coated with a thin adhesive layer or of trapping solid particles by
impact on a surface coated with adhesive
3.1.9
aggregate
relatively stable assembly of dry particles, formed under the influence of physical forces
3.1.10
filter media area
A
fm
area of media contained in the filter
3.1.11
effective filter media area
area of the media contained in the filter (without adhesive spaces or ligament) and passed by air during
operation
3.1.12
exposed filter area
A
exp
area of filter medium in a filter effective for particle capture
3.1.13
nominal filter face area
A
nff
frontal face area of the filter including the header frame which determines the nominal filter face velocity
3.1.14
arrestance
A
measure of the ability of a filter to remove a standard test dust from the air passing through it, under given
operating conditions
NOTE This measure is expressed as a weight percentage.
3.1.15
average arrestance
A
m
ratio of the total amount of loading dust retained by the filter to the total amount of dust fed up to final test
pressure differential
3.1.16
initial arrestance
value of arrestance determined after the first loading cycle in a filter test
NOTE 1 For example, in EN 14799 procedure for the first 30 g of test dust.
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ISO 29464:2011(E)
NOTE 2 This measure is expressed as a weight percentage.
3.1.17
ash
solid residue of effectively complete combustion
3.1.18
fly ash
ash entrained by combustion gases
3.1.19
dust holding capacity
DHC
C
d
amount of loading dust retained by the filter up to final pressure differential
3.1.20
capture
extraction of particles, liquid particles or gases, close to their sources for purposes of collection or sampling
3.1.21
classification
allocation of filters into groups and classes according to relevant aspects of their filtration performance
3.1.22
cleaning (after clogging)
removal of the deposit of solid or liquid particles which has produced clogging
3.1.23
clogging
deposition, progressive or otherwise, of solid or liquid particles on or within a filter medium, causing the flow to
be obstructed
3.1.24
coalescence
action by which liquid particles in suspension unite to form larger particles
3.1.25
concentration
content
quantity of a solid, liquid or gaseous material expressed as a proportion of another material in which it is
contained in the form of a mixture, a suspension or a solution
3.1.26
correlation ratio of sampling points
downstream particle concentration divided by the upstream particle concentration (measured without filter)
3.1.27
particle counter
device for detecting and counting numbers of discrete airborne particles present in a sample of air
3.1.28
condensation particle counter
CPC
type of optical particle counter (3.1.29) in which very fine airborne particles are enlarged by condensation to
a size which may readily be counted by other particle counting methods
NOTE 1 It can provide data on particle numbers but not the original size distribution.
NOTE 2 The ISO committee dealing with CPC is TC 24/SC 4.
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ISO 29464:2011(E)
3.1.29
optical particle counter
OPC
particle counter which functions by illuminating airborne particles in a sample flow of air, converting the
scattered light impulses to electrical impulse data capable of analysis to provide data on particle population
and size distribution
NOTE See ISO 21501-4.
3.1.30
border zone error
with an optical limitation of the measuring volume or by means of the Gaussian distribution of the light
intensity in the laser beam, the particles passing the border of the sensing zone are less illuminated than the
ones passing the centre of the sensing zone
NOTE 1 The border zone error is device- and particle-size-dependent and has a direct effect on the size resolution.
NOTE 2 Due to the border zone error, the particle size is underestimated.
NOTE 3 The larger the particle to be measured, the larger the border zone error.
3.1.31
sizing accuracy
(x)
(x) determined by the function:
xx
measured reference
(x)100
x
reference
3.1.32
sizing resolution
R(x)
indicates which particle sizes can be differentiated by a particle measuring instrument
NOTE The sizing accuracy can be evaluated for any particle size as follows:
22
()xx ()
measured reference
Rx( )100, geometric standard deviation
x
reference
3.1.33
lower size limit
smallest particle diameter with a counting efficiency of 0,5  0,15 (50 %  15 %)
3.1.34
upper size limit
largest particle diameter with a counting efficiency of 0,5  0,15 (50 %  15 %)
3.1.35
sampling flow rate
volumetric flow rate through the instrument
NOTE Any error in the volume flow will affect the reported particle number concentration.
3.1.36
calibration curve
graph depicting the relationship between scattered light intensity and particle size
NOTE For the clear particle size and quantity determination, an unambiguous, monotonically increasing calibration curve
offers advantages. This enables narrower size intervals to be chosen.
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ISO 29464:2011(E)
3.1.37
calibrate
to compare readings from the instrument to be calibrated with those from a reference device
3.1.38
calibration particle
mono-disperse spherical particle with a known mean particle size, e.g. polystyrene latex (PSL) particle, that is
traceable to an international standard of length, and where the standard uncertainty of the mean particle size
is equal to or less than  2,5 %
NOTE The refractive index of (PSL) calibration particles is close to 1,59 at a wavelength of 589 nm (sodium D line).
[ISO 21501-3:2007, definition 2.1]
3.1.39
reference device
primary device possessing accurately known parameters used as a standard for calibrating secondary devices
3.1.40
coagulation losses
particle losses due to collision and adhesion of particles
NOTE Coagulation affects the measured particle parameters as follows: the particle number concentration decreases,
the particle mass concentration remains the same and the particle size increases.
3.1.41
counting rate
N
number of counting events per unit time
3.1.42
zero count rate
N
z
number of counts registered per unit time by the particle counter when air, which is free of particles, is passed
through the measuring volume
3.1.43
cyclone
dust separator or droplet separator utilizing essentially the centrifugal force derived from the motion of the gas
3.1.44
DEHS
DiEthylHexylSebacate
liquid used for generating the DEHS test aerosol
3.1.45
equivalent diameter
diameter of a spherical particle which will give behaviour equivalent to that of the particle being examined
3.1.46
count median diameter of aerosol
number median diameter of aerosol
CMD
d
m
50th percentile of the number distribution of the aerosol
NOTE 50 % of the particles are smaller than the count median diameter and 50 % are larger than the count median
diameter.
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ISO 29464:2011(E)
3.1.47
count mean particle diameter
number mean particle diameter
d
pm
geometric average of the lower and upper limit of the size range
3.1.48
dispersion
operation as a result of which solid particles or liquid particles are distributed in a fluid
NOTE 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”, e.g. DOP (Dioctyl phthalate) liquid, or liquids with similar physical
properties, are dispersed in air to generate a test aerosol.
3.1.49
downstream
area or region into which fluid flows on leaving the filter
3.1.50
droplet
liquid particle of small mass, capable of remaining in suspension in a gas
NOTE In some turbulent systems, for example clouds, its diameter can reach 200 µm.
3.1.51
dust
airborne solid particles which settle by gravity in calm conditions
3.1.52
test dust capacity
TDC
amount of loading dust held by the filter at final test pressure differential
3.1.53
dust control
whole of the processes for the separation of solid particles from a gas stream in which they are suspended
NOTE By extension this also includes the activities involved in the construction and commissioning of a dust separator.
3.1.54
loading dust
synthetic dust formulated specifically for determination of the test dust capacity and arrestance of air filters
NOTE A number of loading dusts are currently used, e.g. ISO fine test dust, ASHRAE dust and JIS-11.
3.1.55
efficiency
E
fraction of contaminant entering the filter which is retained
3.1.56
average efficiency
E
av
value of efficiency which results from averaging the efficiencies determined over a number of discrete intervals
up to the final pressure differential
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ISO 29464:2011(E)
3.1.57
collection efficiency
ratio of the quantity of particles retained by a separator to the quantity entering it with regard to filters, dust
separators and droplet separators
NOTE It is generally expressed as a percentage.
3.1.58
conditioned efficiency
efficiency of the conditioned filter media operating at an average media velocity corresponding to the test air
flow rate in the filter
3.1.59
counting efficiency
E
c
ratio, expressed as a percentage, of detected number concentration of particles divided by the actual number
concentration of particles in a given size or range of sizes
3.1.60
dust loaded efficiency
efficiency of the filter operating at test flow rate and after dust loadings up to final test pressure differential
3.1.61
fractional efficiency
ability of an air cleaning device to remove particles of a specific size or size range
NOTE The efficiency plotted as a function of particle size gives the particle size efficiency spectrum.
3.1.62
initial efficiency
E
i
efficiency of the air cleaning device operating at the test air flow rate
NOTE Expressed in % for each selected size of particle.
3.1.63
integral efficiency
efficiency, averaged over the whole superficial face area of a filter under given operating conditions
3.1.64
local filter efficiency
E
local
efficiency at a specific point of a filter element under given operating conditions
3.1.65
minimum filter efficiency
E
min
minimum value of the filter efficiency curve under given operating conditions
3.1.66
effluent
fluid discharged from a given source into the external environment
NOTE This is a general term describing any fluid discharged from a given source. In this context the discharged fluid
may be liquid or gaseous and may contain associated liquid and/or particulate contaminants.
3.1.67
filter element
filtering material in a preformed shape being a part of a complete filter
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ISO 29464:2011(E)
3.1.68
elutriation
method of separating a mixture of particles according to their settling velocities within a fluid
3.1.69
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 The coincidence error leads to a measured number concentration which is too low and a value for the particle
diameter which is too high.
3.1.70
air filter
apparatus for separating solid or liquid particles or gaseous contaminants from a gas stream
NOTE The apparatus is generally formed of a layer or layers of porous, fibrous or granular material.
3.1.71
brush filter
air filter in which the medium consists of a screen of intermeshing brushes
3.1.72
cartridge filter
compact filter often of cylindrical design
3.1.73
cellular filter
replaceable filter insert which is or may be installed in a multiple bank or wall structure
NOTE Examples of these are HEPA filters, rigid bags and panels.
3.1.74
ceramic filter
filter with a medium consisting of ceramic fibres or sintered porous ceramic
3.1.75
charged filter
filter in which the medium is electrostatically charged or polarized
3.1.76
filter class
range of filtration performances clearly defined by lower and upper limit values
3.1.77
cleanable filter
filter designed to enable the removal of collected dust by application of an appropriate technique
NOTE The removal of collected dust is usually partial.
3.1.78
disposable filter
filter which is not intended to be cleaned or regenerated for re-use
3.1.79
effective filtering area
area of filter medium in the filter which collects dust
3.1.80
electret filter
filter with an electrostatically charged medium
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ISO 29464:2011(E)
3.1.81
efficient particulate air filter
EPA filter
filter with performance complying with requirements of filter class ISO 15 – ISO 30 as per ISO 29463-1
3.1.82
fabric filter
filter medium manufactured either from woven or non-woven textile or a combination of both
NOTE The term is most often applied to dust collectors. In these devices the filtering is effectively carried out by a bed of
deposited dust, the textile providing a supporting substrate.
3.1.83
filter face area
frontal face area of the filter including the header frame
3.1.84
filter face velocity
air flow rate divided by the filter face area
3.1.85
fibrous filter
filter comprising a medium consisting of a mass of fibres, including fine and very fine fibres
NOTE 1 The efficiency of these filters is derived from the presence of very fine fibres which are supported by coarser
fibres in a relatively open structure.
NOTE 2 Fibrous filters are usually disposable.
3.1.86
final filter
air filter used to collect the loading dust passing through or shedding from the filter under test
3.1.87
group of filters
filters of more than one adjacent class within a performance spectrum
3.1.88
HEPA filter
filters with performance complying with requirements of filter class ISO 35 - ISO 45 as per ISO 29463-1
3.1.89
filter insert
replaceable part of a filter which contains the filter medium but which can only operate mounted inside a frame
3.1.90
filter medium
material used for filtering
NOTE The part of a filter on or within which the particles are retained.
3.1.91
metal filter
filter with a medium consisting of metal mesh(es), fibres or sintered porous metal
3.1.92
filter pack
filtering material in a preformed shape being a part of a complete filter
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ISO 29464:2011(E)
3.1.93
panel filter
shallow parallel-faced filter element or cell
3.1.94
particulate air filter
filter designed to remove suspended particles from air flowing through it
3.1.95
pocket filter
bag filter
filter in which the medium is formed into pockets or bags
3.1.96
renewable media filter
filter in which the medium can be replaced
3.1.97
roll filter
filter incorporating a means for advancing new medium
NOTE For example, from a roll.
3.1.98
self-cleaning filter
filters having an inbuilt mechanism for removing collected contaminants
3.1.99
filter type
designation of the structure and test regime of a filter
3.1.100
ULPA filter
filters with performance complying with requirements of filter class ISO 55 - ISO 75 as per ISO 29463-1
3.1.101
nominal air volume flow rate
q
v,nom
air volume flow rate specified by the manufacturer
3.1.102
rated flow
q
vr
gas flow rate through a separator, either as stated by the manufacturer for defined conditions of use, or as
agreed between the interested parties for a particular installation
3.1.103
sampling volume flow rate
representative partial flow rate used for the determination of airborne particle characteristics
3.1.104
service flow
gas flow rate through a separator under given service conditions
3.1.105
test flow
gas flow rate through a separator during a rig test or a site test
NOTE This flow, which can differ from the rated flow, shall be specified or, failing this, agreed between the interested
parties.
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ISO 29464:2011(E)
3.1.106
test volume flow rate
q
vt
volumetric air flow rate used for testing
3.1.107
header frame
integral rigid frame of a filter enabling it to be fastened and sealed against the holding frame
3.1.108
holding frame
rigid structural frame, part of an air handling system into which filters are fastened and sealed
3.1.109
fume
aerosol of solid particles, usually from metallurgical processes, generated by condensation from the gaseous
state generally after volatilization from melted substances and often accompanied by chemical reactions such
as oxidation
NOTE In popular usage, this is referred to as gaseous effluent, often unpleasant and malodorous, which may arise from
chemical processes.
3.1.110
grit
airborne solid particles in the atmosphere or flues
NOTE In the UK, of size greater than 75 µm [see “dust” (3.1.51)].
3.1.111
hood
inlet device for extraction system
3.1.112
housing
device used to hold filter
3.1.113
impact
collision of two particles with each other, or of a particle with a solid or liquid surface
3.1.114
impaction
inertial separation due to mass and velocity of a particle causing divergence from the airflow stream lines onto
individual filter fibres
3.1.115
KCl
solid potassium chloride particles generated from an aqueous solution and used as test aerosol
3.1.116
porous layer
permeable layer of solid material in any form having interstices of small size, generally known as “pores”
3.1.117
leak
point in a filter at which the local penetration exceeds a given value
3.1.118
mist
suspension of droplets in a gas
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ISO 29464:2011(E)
3.1.119
neutralization
action of bringing the aerosol to a Boltzmann charge equilibrium distribution with bipolar ions
NOTE This process is more often described as “discharging”.
3.1.120
particle
small discrete mass of solid or liquid matter
3.1.121
particle bounce
behaviour of particles that impinge on the filter without being retained
3.1.122
mean particle diameter
geometric mean of the upper and lower border diameters in a size range
3.1.123
particle number
N
p
number of particles present in a defined group
3.1.124
particle number concentration
C
N
number of particles per unit of volume of air
3.1.125
particle production rate
Q
number of particles produced per unit of time by an aerosol generator
3.1.126
particle size
d
p
geometric diameter (equivalent spherical, optical or aerodynamic, depending on context) of the particles of an
aerosol
3.1.127
particle size analysis
technique used to measure the size distribution of an assembly of particles
3.1.128
particle size distribution
presentation, in the form of tables of numbers or of graphs, of the experimental results obtained using a
method or an apparatus capable of measuring the equivalent diameter of particles in a sample or capable of
giving the proportion of particles for which the equivalent diameter lies between defined limits
3.1.129
most penetrating particle size
MPPS
d
mpps
particle size at which the minimum of the particle size efficiency curve occurs under test conditions
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ISO 29464:2011(E)
3.1.130
penetration
P
ratio of particle concentration detected downstream versus the particle concentration upstream
NOTE In some industries, the reciprocal of the penetration is known as the “decontamination factor” (DF).
3.1.131
pollutant
contaminant
undesirable solid, liquid or gaseous matter in a gaseous or liquid medium
3.1.132
pollution
contamination
introduction of pollutants into a liquid or gaseous medium, or any undesirable modification of the composition
of a liquid or gaseous medium
3.1.133
precipitation
operation in which particles are separated from a gas stream in which they are suspended
NOTE For example, by the action of an electrical field or a thermal gradient.
3.1.134
electrostatic precipitator
device in which particles become charged and are precipitated on the collecting surface
NOTE Also referred to as electrostatic collector, electrical separator or electrostatic separator.
3.1.135
burst pressure
p
b
value of differential pressure across a filter, above which damage/destruction of the filter media or the
structure occurs
3.1.136
differential pressure
D
p
difference in absolute (static) pressure between two points in a system
3.1.137
mean differential pressure
D
pM
arithmetical mean value of the measured number of differential pressures
3.1.138
final differential pressure
D
pf
differential pressure up to which the filtration performance is measured for classification purposes
3.1.139
recommended final differential pressure
D
pfr
maximum operating differential pressure of the filter as recommended by the manufacturer
3.1.140
initial differential pressure
D
pi
differential pressure of the clean filter operating at its test air flow rate
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ISO 29464:2011(E)
3.1.141
purification
total or partial removal of unwanted constituents from a gaseous medium
3.1.142
re-entrainment
release to the air flow of particles previously collected on the filter
3.1.143
sampling duration
t
sd
time period during which the particles in the sample are counted upstream and downstream
3.1.144
isokinetic sampling
technique for air sampling such that the probe inlet air velocity is the same as the velocity of the air
surrounding the sampling point
3.1.145
scan test
test procedure by which local efficiency or penetration values are determined by sampling filtered air at the
downstream filter face according to a specified grid pattern
3.1.146
sedimentation
separation of particles from the fluid in which they are suspended, by the action of gravity
3.1.147
separator
apparatus for separating solid or liquid particles or gases from a gaseous stream in which they are suspended
or mixed
3.1.148
droplet separator
apparatus for separating suspended liquid particles from a gas stream
3.1.149
dust separator
apparatus for separating suspended solid particles from a gas stream
3.1.150
shedding
release to the air flow of particles due to particle bounce and re-entrainment effects and to the release of
fibres or particulate matter from the filter or filtering material
3.1.151
smoke
visible aerosol resulting from combustion
3.1.152
soot
deposits of agglomerated carbonaceous particles formed by incomplete combustion
3.1.153
suspension
two-phase system in which one phase, the disperse phase, is distributed throughout the other, known as the
continuous phase
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ISO 29464:2011(E)
3.1.154
transmission
ratio of the quantity of particles leaving a filter, dust separator or a droplet separator, to the quantity entering it
3.1.155
upstream
region in a process system traversed by a flowing fluid before it enters that part of the process under
consideration
NOTE The part of the process under consideration in the context of this International Standard will normally be a filter.
3.1.156
filter face velocity
average velocity of the air through the filter face area
3.1.157
filter medium face velocity
u
fm
volume flow rate divided by the effective filter medium area of the filter element
3.1.158
washer
dust separator, droplet separator or gas purifier that depends on a liquid acting as a collecting medium for its
operation
3.2 Gas phase filters
3.2.1
absorption
transport and dissolution of a sorbate into an absorbent to form a homogeneous mixture having the
characteristics of a solution
3.2.2
activated alu
...