ASTM E1554-94

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
An American National Standard
Designation: E 1554 – 94
Standard Test Methods for
Determining External Air Leakage of Air Distribution
Systems by Fan Pressurization
This standard is issued under the fixed designation E 1554; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
1.1 These test methods cover two techniques for measuring 2.1 ASTM Standards:
the air leakage of the sections of air distribution systems that E 631 Terminology of Building Constructions
pass outside the conditioned space in low-rise residential and E 741 Test Methods for Determining Air Change in a Single
small low-rise commercial buildings. Both techniques use air Zone by Means of a Tracer Gas Dilution
flow and pressure measurements to determine the leakage E 779 Test Method for Determining Air Leakage Rate by
characteristics, and include separate measurements of the Fan Pressurization
supply-side and the return-side distribution system leakage. E 1258 Test Method for Airflow Calibration of Fan Pressur-
1.2 These test methods also specify the auxiliary measure- ization Devices
ments needed to characterize the magnitude of the distribution 2.2 ASME Standard:
system air leakage during normal operation (a measurement of MFC-3M Measurement of Fluid Flow in Pipes Using Ori-
pressure differentials across duct leaks during normal fice Nozzle and Venturi
distribution-system operation), and to normalize the distribu-
3. Terminology
tion system’s air leakage by the total recirculating air flow
3.1 Definitions—Refer to Terminology E 631 for definitions
induced by the distribution-system fan.
1.3 The air-leakage measurement portion of these test meth- of other terms used in these test methods.
3.2 air-handling unit—the distribution-system fan and por-
ods is applicable to small temperature differentials and low
wind pressures; the uncertainty in the measured results increase tion of the distribution system that is integral to the furnace,
air-conditioner, or heat-pump.
with increasing wind speeds and temperature differentials.
3.3 air-leakage rate—the volume of air movement per unit
1.4 The proper use of these test methods requires a knowl-
edge of the principles of air flow and pressure measurements. time across the building envelope or the exterior envelope of
the air distribution system.
1.5 These test methods are intended to produce a measure of
the air tightness between an air distribution system and its 3.3.1 Discussion—This movement includes flow through
joints, cracks, and porous surfaces, or combinations thereof.
surroundings exterior to the conditioned space of a building.
1.6 The values stated in SI units are to be regarded as The driving forces for such air leakage in service can be
mechanical pressurization and depressurization, natural wind
standard. The values given in parentheses are for information
only. pressures, and air temperature differentials between the build-
ing interior and the outdoors.
1.7 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the 3.4 building envelope—the boundary or barrier separating
the interior volume of a building from the outside environment.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- 3.5 building pressure difference—the pressure difference
across the building envelope, expressed in pascals (inches of
bility of regulatory limitations prior to use. For specific hazard
statements, see Section 7. water, pounds-force per square foot, or inches of mercury).
These test methods are under the jurisdiction of ASTM Committee E-6 on
Performance of Buildings and are the direct responsibility of Subcommittee E06.41
on Air Leakage and Ventilation. Annual Book of ASTM Standards, Vol 04.11.
Current edition approved Jan. 15, 1994. Published April 1994. Originally Available from American Society of Mechanical Engineers, 345 E. 47th St.,
published as E 1554 – 93. Last previous edition E 1554 – 93. New York, NY 10017.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
E 1554
3.6 distribution-system pressure difference—the pressure
difference across the exterior air-distribution envelope, ex-
pressed in pascals (inches of water, pounds-force per square
foot, or inches of mercury).
3.7 exterior air-distribution envelope—the boundary or bar-
rier separating the interior volume of the air distribution system
from the outside environment or unconditioned spaces.
3.7.1 Discussion—For the purpose of these test methods,
the interior volume is the deliberately conditioned space within
a building, generally not including the attic space, basement
space, and attached structures, unless such spaces are part of
the heating and air conditioning system, such as a crawl space
that acts as a plenum.
FIG. 1 Schematic of Major Components and Measurement Set-Up
3.8 unconditioned space—any space that is not intentionally
for Test Method A
heated or cooled for human occupancy, including attics,
crawlspaces, unfinished basements, attached structures (such as
a garage), or any space completely outside the building
envelope (for example, rooftop ductwork on small commercial
buildings).
4. Summary of Test Methods
4.1 These test methods consist of mechanical pressurization
and depressurization of an air distribution system and the
conditioned space of the building through which it passes,
during which measurements of air flow rates are made over a
range of pressure differentials between the distribution system
and its surroundings outside the conditioned portion of the
building. From the relationship between the measured air flow
FIG. 2 Schematic of Major Components and Measurement Set-Up
rates and pressure differences, the external air leakage charac-
for Test Method B
teristics of the supply and return sides of the air distribution
system are separately evaluated.
4.2 Two alternative measurement and analysis procedures
bution system, the ventilation rate of the building, and poten-
are specified. The first of these techniques, Test Method A, is
tially the entry rate of various air pollutants.
based upon comparisons of the air leakage rates from three fan
5.2 The determination of infiltration energy loads and ven-
pressurization tests: with the entire distribution system in good
tilation rates of residences and small commercial buildings are
communication with the building, with the return side of the
typically based on the assumption that the principal driving
distribution system sealed from the building and the supply
forces for infiltration and ventilation are the wind and indoor/
side, and with the entire distribution system sealed from the
outdoor temperature differences. This can be an inappropriate
building. The second technique, Test Method B, is based upon
two fan pressurization tests utilizing direct measurement of assumption for buildings that have distribution systems that
distribution-system leakage flows: with all but one supply pass through unconditioned spaces, as the existence of rela-
register sealed, and with all but one return register sealed. Both
tively modest leakage from that system has a relatively large
tests in Test Method B are conducted with the supply side
impact on overall ventilation rates. The air leakage character-
sealed from the return side at the distribution-system fan. Test
istics of these exterior distribution systems are needed to
Methods A and B are shown schematically in Figs. 1 and 2,
determine their ventilation, energy, and pollutant-entry impli-
respectively.
cations.
4.3 These test methods also include specifications for the
5.3 Air leakage through exterior air distribution systems
auxiliary measurements to interpret the air leakage measure-
may be treated in the same manner as air leakage in the
ments. These include measurement of the pressures that drive
building envelope as long as the system is not operating (see
air leakage during normal system operation and measurement
Test Method E 779). However, when the distribution-system
of the recirculating flow through the distribution system. The
fan is turned on, the pressures across these leaks are signifi-
former involves measurement of the characteristic pressures
cantly larger than those driving natural infiltration, thereby
across the distribution-system surface, and the latter involves
inducing much larger flows. Thus, it is important to be able to
measurement of the airflow into the return grill(es) with only
isolate these leaks from building envelope leaks. Also, due to
the distribution-system fan in operation.
the different impacts of supply-side and return-side
5. Significance and Use
distribution-system leaks, these two air leakage pathways shall
be measured separately. The leakage of air distribution systems
5.1 Air leakage between an air distribution system and
unconditioned spaces affects the energy losses from the distri- must be measured in the field, as it has been shown that
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
E 1554
workmanship is often more important than design in determin- 6.2.4 Air Flow Measuring Device (A only)—A device to
ing the leakage of these systems. Also, it is important to measure air flow through the air moving equipment (6.2.1)
distinguish leaks to the conditioned parts of a building from within 63 % of the true value. The calibration of this air-flow
leaks to the outside. measurement system shall follow Test Method E 1258. The
5.4 As an alternative to the fan pressurization method, air size of the air moving equipment shall be matched to the air
flow measuring system so that the linear flow velocity falls
infiltration with and without an air distribution system operat-
ing may be measured directly using the tracer dilution method within the range of measurement of the air flow meter.
(see Test Method E 741). The fan pressurization method
6.2.5 Pressure-Measuring Device (A and B)—A manometer
provides an indirect way to relate the infiltration rate to the
or pressure indicator to measure pressure differences with an
leakage of the building and the air distribution system.
accuracy of 60.5 Pa (60.002 in. H O).
5.5 The fan pressurization method for measuring envelope
6.2.6 Duct Pressure Measuring Probe (A and B)—A probe
leakage (Test Method E 779) and the fan pressurization method
to measure the static pressure within a duct under flow
for measuring the external leakage of air distribution systems
conditions (that is, a pressure probe with a small velocity-
have several advantages over the tracer dilution method. The
pressure coefficient).
fan pressurization method produces results that characterize the
6.2.7 Air Temperature Measuring Device (A and B)—To
air tightness of the building envelope and the air distribution
give an accuracy of 60.5°C (1°F).
systems. The fan pressurization method for measuring the
6.2.8 Wind Speed Measuring Device (A only)—To give an
external leakage of air distribution systems is used: to compare
accuracy within 60.25 m/s (0.5 mph) at 2.5 m/s (5 mph).
the relative air tightness of several similar air distribution
6.2.9 Simultaneous Pressure and Flow Measurement System
systems, to identify the leakage sources and rates of leakage
(A only, suggested for B)—A system that provides for essen-
from different components of an air distribution system, and to
tially simultaneous measurement of building envelope and
determine the air leakage reduction for individual retrofit
distribution-system pressures, as well as building envelope and
measures applied incrementally on an existing air distribution
distribution-system flows. Three alternative systems are: a
system.
computerized data acquisition system, a multi-channel sample
and hold system, and an interleaved multi-point sampling
6. Apparatus
technique (that is, sequential recording of the pressures and
6.1 The following description of apparatus is general in
flow signals averaged over at least three sets of signal-series
nature. Any arrangement of equipment using the same prin-
samples).
ciples and capable of performing the test procedure within the
6.3 Blower Door Assembly—An accepted variation of air-
allowable tolerances is permitted. Those items required for Test
moving, flow-regulating, and flow-measuring equipment. Is-
Method A are labeled (A only), those for Test Method B are
sues particular to this assembly are:
labeled (B only), and those for both test methods are labeled (A
6.3.1 The door mount for the fan or blower must be
and B). Most of the components are illustrated in Figs. 1 and
2. adjustable to fit common door openings.
6.2 Major Components: 6.3.2 The fan or blower shall possess a variable-speed motor
6.2.1 Air-Moving Equipment (A and B)—A fan, blower, or to accommodate the wide range of required flow rates up to 1.4
3 3
blower door assembly that is capable of moving air into and out m /s (3000 ft /min).
of the conditioned space at the flow rates required to create the
full range of test pressure differences (10 to 60 Pa). The system
7. Hazards
shall provide constant air flow at each incremental pressure
7.1 Glass should not break at the pressure differences
difference at fixed pressure for the period required to obtain
normally applied to the building, however, protective eye wear
readings of air flow rate. The air moving equipment shall be
shall be provided to personnel.
able to accomplish both pressurization and depressurization of
7.2 When conducted in the field, safety equipment required
the conditioned space and distribution system.
for general field work shall be supplied, such as safety shoes,
6.2.2 Air Flow-Regulating System (A and B)—A device
hard hats, etc.
such as a damper, or variable speed motor control, that will
7.3 As air-moving equipment is involved in this test, a
regulate and maintain air flow through the air moving equip-
proper guard or cage to house the fan or blower and to prevent
ment (6.2.1) and pressure difference across the leaks within
accidental access to any moving parts of the equipment must be
specific limits.
provided.
6.2.3 Duct Flow Measurement Apparatus (A and B)—A
7.4
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