SIST EN ISO 12569:2001
(Main)Thermal insulation in buildings - Determination of air change in buildings - Tracer gas dilution method (ISO 12569:2000)
Thermal insulation in buildings - Determination of air change in buildings - Tracer gas dilution method (ISO 12569:2000)
This standard describes the use of tracer gas dilution for determining a single zone's air change as induced by weather conditions or mechanical ventilation. The procedures for tracer gas dilution include concentration decay, constant injection, and constant concentration. Tracer gas concentration is determined by a gas analyzer. Air change rate is directly calculated from the rate of change of tracer gas concentration by the tracer gas method. Airflow rate is calculated directly from the tracer gas flow rate by the constant injection or constant concentration method.
Wärmetechnisches Verhalten von Gebäuden - Bestimmung des Luftwechsels in Gebäuden - Indikatorgasverfahren (ISO 12569:2000)
Diese Norm beschreibt die Anwendung des Indikatorgasverfahrens zur Bestimmung des durch Witterungsbedingungen oder maschinelle Lüftung hervorgerufenen Luftwechsels einer einzelnen Zone. Zu den Indikatorgasverfahren gehören das Prüfverfahren mit abfallender Konzentration, das Prüfverfahren mit konstanter Injektion und das Prüfverfahren mit konstanter Konzentration. Die Konzentration des Indikatorgases wird mit Hilfe eines Gasanalysators bestimmt. Die Luftwechselrate wirdbeim Konzentrationsabklingverfahren direkt aus dem Konzentrationsabfall über die Zeit bestimmt.
Isolation thermique dans les bâtiments - Détermination du renouvellement d'air dans les bâtiments - Méthode de dilution de gaz traceurs (ISO 12569:2000)
Toplotna izolacija v stavbah - Ugotavljanje števila izmenjav zraka v stavbah - Metoda redčenja indikatorskega plina (ISO 12569:2000)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 12569:2001
01-september-2001
7RSORWQDL]RODFLMDYVWDYEDK8JRWDYOMDQMHãWHYLODL]PHQMDY]UDNDYVWDYEDK
0HWRGDUHGþHQMDLQGLNDWRUVNHJDSOLQD ,62
Thermal insulation in buildings - Determination of air change in buildings - Tracer gas
dilution method (ISO 12569:2000)
Wärmetechnisches Verhalten von Gebäuden - Bestimmung des Luftwechsels in
Gebäuden - Indikatorgasverfahren (ISO 12569:2000)
Isolation thermique dans les bâtiments - Détermination du renouvellement d'air dans les
bâtiments - Méthode de dilution de gaz traceurs (ISO 12569:2000)
Ta slovenski standard je istoveten z: EN ISO 12569:2000
ICS:
91.120.10 Toplotna izolacija stavb Thermal insulation
SIST EN ISO 12569:2001 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 12569:2001
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SIST EN ISO 12569:2001
INTERNATIONAL ISO
STANDARD 12569
First edition
2000-11-01
Thermal performance of buildings —
Determination of air change in buildings —
Tracer gas dilution method
Performances thermiques des bâtiments — Détermination du
renouvellement d'air dans les bâtiments — Méthode de dilution de gaz
traceurs
Reference number
ISO 12569:2000(E)
©
ISO 2000
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SIST EN ISO 12569:2001
ISO 12569:2000(E)
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ii © ISO 2000 – All rights reserved
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SIST EN ISO 12569:2001
ISO 12569:2000(E)
Contents Page
Foreword.iv
Introduction.v
1 Scope .1
2 Normative reference .1
3 Terms and definitions .1
4 Apparatus .2
5 Procedure .4
6 Expression of results .8
7 Accuracy.10
8 Test report .10
Annex A (informative) Tracer gas analyser accuracy.11
Annex B (informative) Tracer gas analyser calibration.13
Annex C (informative) Confidence intervals.14
Annex D (informative) Propagation of error analysis.16
Annex E (informative) How to choose the test methods.18
Annex F (informative) Types of tracer gas .19
Annex G (informative) Details on the test report .20
Bibliography.22
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SIST EN ISO 12569:2001
ISO 12569:2000(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 3.
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 International Standard may be the subject of
patent rights other than those identified above. ISO shall not be held responsible for identifying any or all such
patent rights.
International Standard ISO 12569 was prepared by Technical Committee ISO/TC 163, Thermal insulation,
Subcommittee SC 1, Test and measurement methods.
Annexes A to G of this International Standard are for information only.
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SIST EN ISO 12569:2001
ISO 12569:2000(E)
Introduction
Air change often accounts for a significant portion of the heating or air-conditioning load of a building. It also affects
the moisture and contaminant levels in the building. Moisture-laden air passing through cracks in the building
envelope under the influence of air pressure differences and through structural elements under the influence of
vapour pressure differences can condense and cause material degradation. Air flow and air change rates depend
on the size and distribution of air leakage sites, pressure differences induced by wind and temperature, mechanical
system operation, and occupant behaviour. An appropriate level of ventilation is also required in all buildings for
hygiene reasons.
This International Standard presents three test methods that use the measurement of tracer gas concentrations to
determine air change in a building or other enclosure that can be characterized as a single zone. The measurement
of tracer gas concentration, and sometimes the volume rate of flow at which the tracer gas is injected into the zone,
allows calculation of the volume rate of air flow leaving the zone. The volume rate of incoming air flow can be
inferred from this. The three test methods presented are:
a) tracer gas decay (5.4), which tracks the decay rate of tracer gas concentration after an initial injection of tracer
gas,
b) constant injection (5.5), which tracks the tracer gas concentration resulting from a known, constant injection
rate of tracer gas, and
c) constant concentration (5.6), which tracks the amount of tracer gas required to maintain it at a constant
concentration at a constant level.
Each test method employs specific tracer gas injection and sampling strategies. Other techniques exist, but are
beyond the scope of these test methods.
Because air change depends on such variable conditions as building operation, wind speed, and indoor-outdoor
temperatures, this International Standard does not provide information about building airtightness directly.
ISO 9972 should be used to measure airtightness.
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SIST EN ISO 12569:2001
INTERNATIONAL STANDARD ISO 12569:2000(E)
Thermal performance of buildings — Determination of air change
in buildings — Tracer gas dilution method
1 Scope
This International Standard describes the use of tracer gas dilution for determining the air change in a single zone
as induced by weather conditions or mechanical ventilation. The procedures for tracer gas dilution include
concentration decay, constant injection and constant concentration. Tracer gas concentration is determined by a
gas analyser. Air change rate is directly calculated from the rate of change of tracer gas concentration by the tracer
gas decay method. Air flow rate is calculated directly from the tracer gas flow rate by the constant injection or
constant concentration method.
These test methods are restricted to any single tracer gas. The associated data analysis assumes that the tracer
gas concentration can be characterized within the zone with a single value.
NOTE The constant concentration test method given in 5.6 is usually used for multiple zones and allows the measurement
of the air flow rate from the outside to each zone, if the residential zones are kept at the same concentration.
2 Normative reference
The following normative document contains provisions which, through reference in this text, constitute provisions of
this International Standard. For dated references, subsequent amendments to, or revisions of, any of these
publications do not apply. However, parties to agreements based on this International Standard are encouraged to
investigate the possibility of applying the most recent edition of the normative document indicated below. For
undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC
maintain registers of currently valid International Standards.
ISO 7345, Thermal insulation — Physical quantities and definitions.
3 Terms and definitions
For the purposes of this International Standard, the terms and definitions given in ISO 7345 and the following
apply.
3.1
air flow rate
�
V
total volume of air passing through the zone to and from the outdoors per unit of time
3 3
NOTE It is expressed in cubic metres per second or per hour (m /s, m /h).
3.2
air change rate
n
ratio of the total volume of air passing through the zone to and from the outdoors per unit of time to the volume of
the zone
NOTE It is expressed in reciprocal seconds or reciprocal hours (1/s, 1/h).
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ISO 12569:2000(E)
3.3
building envelope
boundary or barrier separating the interior volume of a building from the outside environment
3.4
single zone
space or set of spaces wherein the concentration of a tracer gas can be maintained uniformly throughout and that
only exchanges air with the outside
3.5
tracer gas
gas that can be mixed with air and measured in very small concentrations in order to study air change
NOTE The tracer gas is not used to study air movement. Rather it is used to assess air transfer, exchange or infiltration.
Types of tracer gas, measuring apparatus, limits of measurement, allowable concentration and specific gravity of the tracer
gases are given in annex F. A gas at a temperature extremely different from that of the room should not be used for the tracer
gas dilution method.
4 Apparatus
The apparatus includes means for distributing the tracer gas, means for obtaining air specimens, a gas analyser to
measure tracer gas concentration in the air specimens, and other measurement devices, as follows.
4.1 Tracer gas concentration standard
Use a source of air with a known concentration of tracer gas.
Use the tracer gas within safe limits for concentration. Avoid conditions where the amount of tracer gas that may be
absorbed onto surfaces and into subordinate enclosures is significant, compared with the amount of tracer gas in
the zone. Avoid conditions where the added amount of tracer gas is small, compared to the atmospheric
background level of that gas. The use of radioactive tracer gases should be avoided.
4.2 Tracer gas injection and distribution apparatus
Choose an apparatus from one or more of the following, as appropriate to the test method.
4.2.1 Graduated syringe, or other container of known volume with a means for controlled release of its content.
4.2.2 Compressed tracer gas supply, with a critical orifice, a critical orifice metering valve, an electronic mass
flow controller, or other tracer gas flow rate measurement and control device.
4.3 Tracer gas distribution devices
Choose an apparatus from one or more of the following, as appropriate to the test method.
4.3.1 Fans that permit good mixing within the zone of manually-injected tracer gases.
These fans are required so as not to give any influence on the air change rate.
4.3.2 Tubing networks that dispense tracer gas via manifold or switches.
All parts of the tubing network shall be clearly labelled "Tracer Gas Only" and keyed to the location that receives
the tracer gas.
NOTE Leaks in tubing networks can release tracer gas at unwanted locations and in uncontrolled unwanted
concentrations.
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4.4 Tracer gas sampling apparatus
4.4.1 Materials for sampling apparatus
Materials used in tracer gas sampling systems shall be nonabsorbent, non-reactive, and non-diffusive to the tracer
gas in use. Depending on the tracer gas, desirable materials may include glass, copper, and stainless steel. Metal
foil may be appropriate for flexible containers. Other acceptable materials may include polypropylene, polyethylene,
and polyamide. Materials that absorb tracer gas may cause major inaccuracies in the measurement.
NOTE Inappropriate materials may release substances that interfere with the tracer gas analyser. Depending on the tracer
gas, materials to avoid include soft plastics.
4.4.2 Manual samplers, including syringes, flexible bottles, or air specimen bags with a capacity of at least three
times the minimum specimen size of the gas analyser used.
Each shall have a label that may be keyed to a record of the time and location that it was used.
Manual samplers shall have an airtight seal to assure that the specimen is not diluted or contaminated. Avoid
reusing sample containers without first confirming that they are not contaminated with tracer gas.
4.4.3 Sampling network for in-situ analysis
Label all parts "Sampling only".
The sampling network may include:
a) tubing that is keyed to the location sampled;
b) manifold that connects to individual legs of the network and receives air with mutual equal air flow rates,
combines them and leads to the gas analyser;
c) selection switch that permits sampling of individual legs of the network going to the gas analyser;
d) pump that delivers air specimens through the network to the gas analyser at a rate that minimizes delays
between the time air specimens leave the zone and the time they reach the gas analyser;
e) sampling device for laboratory analysis, including, for example, syringes or bag samplers or direct to the gas
analyser that may be programmed to draw air specimens at defined time intervals.
NOTE Separate automatic samplers may be placed at different locations throughout the zone to be evaluated.
4.5 Gas analyser
The gas analyser shall be suitable for the tracer gas used and the concentrations applied to conform to the test
procedure within the zone studied. It should be properly calibrated and have a measurement uncertainty of less
than� 5 % at the concentrations employed in the tracer gas study.
4.6 Data acquisition and control system
NOTE This equipment is optional for all but the constant concentration technique.
4.6.1 Data acquisition device, with appropriate interfaces to provide indoor and outdoor temperatures, wind
speed, wind direction, and tracer gas concentration data to a computer or other machine-readable data storage
unit.
4.6.2 Process controller, i.e. a computer that uses current tracer gas concentration information to control
metering and switching equipment to deliver tracer gas to the appropriate parts of the network.
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NOTE When a feedback process controls the gas concentrations based on gas concentration measurements, an algorithm
that minimizes deviation from the target concentration is required. A digital optimal adaptive proportional control algorithm has
been used effectively for constant concentration measurements.
4.7 Portable meteorological station (optional), i.e. a device that records wind speed and direction and outdoor
temperature.
4.8 Temperature measurement sensor (optional), i.e. thermometer or recorder for the output of
thermocouples, thermistors and resistance thermal devices.
4.9 Timing device (optional), i.e. device to provide a common standard for all events relating to the
measurement procedure, including gas injection times, sampling times, and meteorological driving forces.
The time difference between events shall be determined within a 1 % uncertainty by the timing device.
5 Procedure
5.1 General
Choose the tracer gas decay method (5.4) to determine air change rate, n. To determine the air flow rate, V,
choose either the constant injection (5.5) or the constant concentration (5.6) method. If the zone configuration
makes maintaining a uniform concentration difficult for the decay (5.4) or constant injection (5.5) methods, then
choose the constant concentration (5.6) method with automated networks for tracer gas injection and for air
sampling.
5.2 Preparation of the building envelope
The preparation of the building envelope depends on the purpose of the determination of the air flow rate, as
follows.
a) When measuring only the air flow rate by infiltration into a building as the result of a corresponding weather
situation (e.g. in cases of energetic considerations), all internal doors should be opened, all windows and
external doors should be closed and the ventilation equipment (if any) shall be switched off.
b) When measuring only the air flow rate by infiltration into a room (e.g. for hygienic considerations), the internal
doors and those to the adjoining rooms should be closed (possibly sealed off) and the ventilation equipment (if
any) shall be switched off if there is no leakage interference from adjoining rooms. All windows and external
doors should be closed and the ventilation equipment (if any) shall be switched off.
c) When assessing of the natural ventilation of a building (e.g. tilted windows), the corresponding boundary
conditions shall be watched.
It should be emphasized that there is no general method of envelope preparation, because the purpose of air flow
rate measurements can have different reasons. In the case where the internal doors are closed, the constant
concentration method may be applied for air change measurement.
5.3 Ancillary measurements
Determine and record the indoor temperatures throughout the building zone. Obtain outdoor temperature, wind
speed and wind direction from a nearby meteorological station or a portable meteorology station. Determine the
status of building ventilation systems and envelope openings. Determine the volume of the zone, as required.
5.4 Tracer gas decay method
Introduce a small volume of tracer gas uniformly into the zone, sufficient to cause a concentration at the high end of
the detection limits of the gas analyser. Mix the tracer gas in the zone, so that its concentration varies by less
than 10 % from the mean value within the zone. Confirm a uniform initial concentration with simultaneous air
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ISO 12569:2000(E)
specimens taken at least at two different places in the zone. Sample the air in the zone a minimum of two known
times. As a recommended option, obtain additional air specimens at two different times to test the hypothesis that
the air change rate was constant during the test. At the end of the sampling period, again confirm that the tracer
gas concentration varies throughout the zone by less than 10 % with simultaneous air specimens. Analyse the
tracer gas concentrations of the specimens. Figure 1 gives an overview of this test method.
NOTE The use of more than two samples permits determination of whether the air change rate was constant during the
period or allows the choice of a period when the air change rate was constant.
NOTE For each step, perform the corresponding action in Table 1. The gas storage vessel should be stored outside the
building at all times during the test.
a
Recommended
b
Minimum
Figure 1 — Overview of the tracer gas decay method
Table 1 — Summary procedure for the tracer gas decay method
Step Action
1 Measure and inject tracer gas.
2 Mix tracer gas uniformly.
3 Obtain spatial samples.
4 Obtain samples a minimum of two times.
5 Obtain spatial samples.
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ISO 12569:2000(E)
5.5 Constant injection method
Inject the tracer gas uniformly into the zone at a constant rate of flow, that is known within 2 % and is sufficient to
cause a concentration within the detection limits of the gas analyser. Mix the tracer gas in the zone, so that its
concentration varies by less than 10 % within the zone. Confirm a uniform concentration with simultaneous air
samplings at diverse locations in the zone. Before the concentration measurement samples are taken, it is
essential that the concentration of tracer gas in the zone has approached equilibrium for the prevailing weather
conditions, not just an even distribution within the zone. Sample the air in the zone a minimum of two known times.
As a recommended option, obtain additional air specimens at two different times to test the hypothesis that the air
change rate was constant during the test. With the end of the sampling period, again confirm that the tracer gas
concentration varies throughout the zone by less than 10 % by collecting simultaneously air specimens at the
diverse locations with simultaneous air specimens. Analyse the tracer gas concentrations of the specimens.
Determine that the concentration remains within � 20 % of the average concentration during the measurement
period. Determine the zone volume to within 15 % of the true value. Figure 2 gives an overview of this test method.
NOTE 1 The use of more than two samples permits determination of whether the air change rate was constant during the
period or allows the choice of a period when the air change rate was constant.
NOTE 2 When the constant injection method is used for long-term measurements, the checks on how constant the
concentration remains during the measurement period are irrelevant. For long-term tests the measurement period is broken
down into short time periods (of say 30 min) and the results analysed for each of those short periods so that the trend over time
of changing air change rate (or air flow rate) with weather or other parameters may be assessed.
Key
1 Gas 4 Gas analyser
2 Data aquisition 5 Pump
3 Tracer gas 6 Measured zone
Figure 2 — Overview of the constant injection method
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SIST EN ISO 12569:2001
ISO 12569:2000(E)
5.6 Constant concentration method
Inject tracer gas uniformly into the zone at a known rate that causes a constant concentration near a target
concentration C that is within the detection limits of the gas analyser. Mix the tracer gas in the zone, so that its
targ
concentration varies by less than 10 % within the zone. Confirm a uniform concentration with simultaneous air
samplings at diverse locations in the zone. Before concentration measurement samples are taken, it is essential
that the concentration of tracer gas in the zone has stabilized around the target concentration. Sample the air in the
zone frequently enough to allow analysis of the tracer gas concentration and to control the rate of flow to maintain
the constant concentration to within 5 % of the target concentration, based on the measurement of tracer gas
concentration. It is assumed that the volume of the sampled air is negligible, compared to the air change rate.
Figure 3 gives an overview of this test method.
NOTE 1 This method allows the determination of a combined air flow rate from multiple zones that comprise the entire
building.
NOTE 2 When the constant concentration method is used for long-term measurements the measurement period is broken
down into short time periods (of say 30 min) and the results analysed for each of those short periods so that the trend over time
of changing air change rate (or air flow rate) with weather or other parameters may be assessed.
Key
1 Switch 5 Gas analyser
2 Gas controller 6 Pump
3 Data aquisition 7 Measured zone
4Tracergas
Figure 3 — Overview of the constant concentration method
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SIST EN ISO 12569:2001
ISO 12569:2000(E)
6 Expression of results
6.1 Calculation of air change rate
As a minimum, calculate the mean air change rate, n , determined by the tracer gas decay method, using
av
equation (1):
lnCt( ) – lnC t
��
12
n= (1)
av
tt–
21
where
C(t ) is the specimen concentration at time t ;
1 1
C(t ) is the specimen concentration at time t ;
2 2
t is the time of the first sampling, in seconds or hours;
1
t is the time of the last sampling, in seconds or hours.
2
NOTE Two points do not reveal whether n has changed over the sampling period due to environmental factors or
experimental error.
6.2 Test for constant air change rate
As a recommended option, if concentrations were measured at times between the beginning and final specimens,
plot ln C (t)against t and perform a regression analysis, using equation (2) (see also C.1), of the logarithms of the
tracer gas concentration measurements against time to test the hypothesis that the air change rate, n, was constant
during the period:
lnCt( ) = –nt+lnC(0) (2)
where
C(t) is the specimen concentration at time t;
t is the time of sampling, in seconds or hours;
C(0) is the specimen concentration at time zero.
6.3 Calculation of air flow rate from constant tracer gas flow
�
As a minimum, calculate the mean air flow rate, V , determined by the constant injection method for the
av
measurement period, using equation (3):
� � ��
1 C
�� V
zone 2
V =V – ln (3)
tra
av ��
��
C – C
�� tt
21 1
av ��
where
�
V is the flow rate of the tracer gas, in cubic metres per second;
tra
��
��111 1
= + + .+ /k
����
C
��
�� CC C
12 k
av
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ISO 12569:2000(E)
1
��
is the the average of the inverse of the concentrations of k specimens obtained at different times;
��
C
��
av
C is the spatially averaged specimen concentration at the beginning of the measurement period;
1
C is the spatially averaged specimen concentration at the end of the measurement period;
2
t is the time at the beginning of the measurement period, in seconds or hours;
1
t is the time at the end of the measurement period, in seconds or hours;
2
k is the number of specimens;
V is the volume of the zone, in cubic metres.
zone
NOTE Two points do not reveal whether n has changed over the sampling period due to environmental factors or
experimental error.
6.4 Test for constant air flow rate
�
As a recommended option, test the hypothesis that the air flow rate,V , was constant during the p
...
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