ASTM E3158-18

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E3158 − 18
Standard Test Method for
Measuring the Air Leakage Rate of a Large or Multizone
Building
This standard is issued under the fixed designation E3158; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
1.1 This standard test method provides a quantitative field-
1.11 This international standard was developed in accor-
test procedure and calculation method for assessing an air
dance with internationally recognized principles on standard-
leakage rate using a fan-induced pressure differential(s) across
ization established in the Decision on Principles for the
thebuildingenvelope, generated by blower doors orequivalent
Development of International Standards, Guides and Recom-
equipment.
mendations issued by the World Trade Organization Technical
1.2 Building setup conditions in accordance with defining
Barriers to Trade (TBT) Committee.
the test boundaries appropriate for testing the envelope’s air
2. Referenced Documents
leakage are defined in this test method.
2.1 ASTM Standards:
1.3 Procedure to determine the air pressure boundaries of
E456 Terminology Relating to Quality and Statistics
the test envelope to be tested are provided in this test method.
E631 Terminology of Building Constructions
1.4 This test method applies to all multizone and large
E779 Test Method for DeterminingAir Leakage Rate by Fan
building types and portions or subsections thereof.
Pressurization
1.5 This test method defines three test procedures: multi-
E1186 Practices for Air Leakage Site Detection in Building
point regression, repeated single point, and repeated two-point
Envelopes and Air Barrier Systems
air leakage rate testing.
E1258 Test Method for Airflow Calibration of Fan Pressur-
ization Devices
1.6 This test method allows for testing the test envelope in
E1827 Test Methods for Determining Airtightness of Build-
a pressurized condition, a depressurized condition, or in both
ings Using an Orifice Blower Door
conditions and averaging the results.
E2178 Test Method forAir Permeance of Building Materials
1.7 This test method applies to an air leakage rate specifi-
E2357 TestMethodforDeterminingAirLeakageRateofAir
cation with a reference pressure greater than 10 Pa (0.04 in.
Barrier Assemblies
WC) and not greater than 100 Pa (0.40 in. WC).
3. Terminology
1.8 This test method describes two methods of preparation
for the building in order to conduct the test: the building
3.1 Definitions:
envelope where HVAC-related openings are excluded, and on
3.1.1 For definitions of general terms related to building
theoperationalenvelopewheretheHVAC-relatedopeningsare
construction used in this test method, refer to Terminology
included.
E631 and for general terms related to accuracy, bias, precision,
and uncertainty, refer to Terminology E456.
1.9 Units—The values stated in SI units are to be regarded
as standard. The values given in parentheses after SI units are
3.2 Definitions of Terms Specific to This Standard:
provided for information only and are not considered standard.
3.2.1 baseline pressure, n—internal test envelope pressure
with the air movement equipment off and sealed, recorded
1.10 This standard does not purport to address all of the
while the building is configured for the test.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
3.2.2 building envelope, n—defined boundary of the test
sample to determine its air leakage rate excluding the HVAC-
related devices (HVAC devices sealed).
This test method is under the jurisdiction of ASTM Committee E06 on
Performance of Buildings and is the direct responsibility of Subcommittee E06.41 For referenced ASTM standards, visit the ASTM website, www.astm.org, or
on Air Leakage and Ventilation Performance. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved Dec. 1, 2018. Published January 2019. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
E3158–18. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E3158 − 18
3.2.3 envelope pressure, n—differential in air pressure 4.2 This test method describes the methods consisting of
across the envelope (that is, between a building or zone and the multipoint regression, repeated single point and repeated two-
outdoors). point pressure testing, mechanically inducing a pressure dif-
ferential between the test envelope and any surrounding zones,
3.2.4 equivalent leakage area (EqLA), n—The cross-
the exterior, or another environment. Different preparation of
sectional area of a sharp-edged hole that would have the same
the building’s mechanical systems allows for both the building
leakage flow rate as the building if both were subjected to a 10
envelope and the operational envelope to be tested. Test
Pa indoor/outdoor pressure difference.
parametersallowthetesttobeconductedonlargeormultizone
3.2.5 HVAC, n—heating ventilating and air conditioning.
buildings within defined weather conditions.
3.2.6 induced envelope pressure, n—an internal envelope
pressure caused by the operation of air moving equipment.
5. Significance and Use
3.2.7 multizone building, n—building or enclosure that con-
5.1 This test method does not establish requirements for
sists of more than one occupancy class or rating, separated by
airtightness but provides means of assessing compliance with
a boundary layer designed to control the movement of air
specified air-leakage rates established elsewhere.
between the different zones.
5.2 This test method is used to determine the airtightness of
3.2.8 normalized leakage area, n—airflow rate measured
building envelopes or portions thereof by measuring the air
that is normalized to the test envelope surface area (the test
leakage rate at specified reference pressure differentials.
envelope boundary as defined in 9.1.1).
5.3 This test method provides:
3.2.9 operational envelope, n—defined boundary of the
5.3.1 Specific directions for determining acceptable weather
sample to determine its air leakage rate that consists of the
conditions for conducting the test.
building envelope, and any HVAC-related penetrations.
5.3.2 Two different test boundary preparation conditions;
3.2.9.1 Discussion—HVAC devices are shut off but left
buildingenvelope(9.1.1.1),andoperationalenvelope(9.1.1.2).
unsealed.
5.3.3 Testing conducted in a range of pressures from 10 Pa
3.2.10 single zone, n—building, enclosure, or test envelope
(0.04 in. WC) to 100 Pa (0.40 in. WC).
boundary, without any interior boundary layers that control the
5.4 Ameasurementoftheair-leakagerateoftheconstructed
movement of air between different areas within that zone, or
building envelope. Test methods that measure the air per-
multiple zones configured to achieve a single zone condition.
meance of materials (Test Method E2178) and air leakage of
3.2.11 single zone condition, n—condition when the internal
assemblies (Test Method E2357) alone do not address the
pressure within a defined space or test envelope boundary
various complexities of the constructed building envelope,
differs by no more than 10 % when measured anywhere within
including but not limited to design, sequence, constructability,
that zone.
workmanship, and the transitions between assemblies.
3.2.12 specified air leakage rate, n—maximum allowable
5.5 This test method applies to all multizone and large
airflow rate from a specified induce pressure differential into a
building types and portions or subsections of buildings. It can
building envelope or test zone boundary, expressed in L/(s·m )
be used to test envelopes that consist of a single zone or
at 75 Pa.
subsections of a zone that can be tested as a single zone. Test
3.2.13 specified reference pressure, n—the induced test
envelopes that are entirely composed of subsections separated
envelope pressure at which the results are required to be
by interior partitions or floors, or both, may be tested as a
reported by the project specification.
single zone by maintaining baseline relationships between
3.2.14 test envelope, n—boundary of a building or a portion
these subsections throughout testing. (See Appendix X1. See
of a building that is configured to a single zone condition to be
alsoTestMethodsE779andE1827.)Isolatedsubsections,each
tested, as defined by the consultant.
with its own specified air-leakage rate, shall be treated as
separate test envelopes and tested separately. While testing
3.2.15 test pressure, n—induced pressure (not baseline ad-
isolated subsections, monitoring must be conducted for any
justed) into the test envelope, measured while test fans are in
extraneous/flanking air movement between the different zones.
operation.
5.6 The building preparations prior to testing (fenestration
4. Summary of Test Method
positions and preparation of intentional openings such as
4.1 This test method provides quantitative test and analysis
HVAC penetrations and equipment) are critically important
methods to determine whether a building envelope has met a
and can have a strong influence on the final test results. This
specified air leakage rate (defined by others). During the test,
test method includes guidance for testing of the building
the total airflow through the test fans and corresponding
envelope both including and excluding HVAC-related open-
induced envelope pressures are measured. The relationship
ings.
between the airflows and induced pressures are used to
5.7 Compliance with a specified air leakage rate does not
measure the air leakage rate of the envelope. Specifications for
imply that all potentially problematic leaks have been sealed.
air leakage rates of an envelope are written in terms of the
maximum allowable airflow rate from a specified induce 5.8 While this test determines the air leakage rate of an
pressure differential. envelope, it does not identify the location of leakage sites.
E3158 − 18
NOTE 1—See, for example, Practices E1186 for locating leaks. The
the building, the equipment, placement of signage, and barri-
location of leaks, in addition to their cumulative leakage area, is also an
cades for hazard protection, and considerations for fire spread
important determinant of leakage under normal operating conditions.
changes with the opening of fire doors, dampers, vents, and
alteration of fire zones during the duration of the testing.
6. Apparatus
7.5.1 Note that alterations to fire spread should be autho-
6.1 The following is a general description of the required
rized by the Authority Having Jurisdiction (AHJ) as a stake-
apparatus. Any arrangement of equipment using the same
holder participant in the process. A fire watch, change in
principles and capable of performing the test procedure within
response time, or other measures may be necessary as ap-
the allowable tolerances shall be permitted.
proved by the AHJ.
6.2 Major Components:
7.6 Debris, Fumes, and Temperature—The blower or fan
6.2.1 Air-Moving Equipment—Fans, blowers, blower door
equipment used to pressurize or depressurize the test envelope
assemblies, or HVAC air movement components that are
presents hazards to the interior not limited to dust, debris,
capable of moving air into and out of the conditioned space at
indoor air quality, occupancy, occupant comfort, plants,
the required airflow rates under a prescribed range of induced
furnishings, finishes, and artwork. These hazards can be
test pressure differentials. The system shall provide control of
minimized by the location of the test fans.
airflow sufficient to perform the selected test sequence (See
Section 9).
7.7 Combustion Appliances—Adjust all combustion appli-
ances so they do not turn on during the test. This is commonly
NOTE 2—If using the HVAC system as the air movement equipment for
the test, then the test is limited to only the Building Envelope (HVAC-
done by temporarily turning off power to the appliance, or
related openings excluded) configuration, and not the Operational Enve-
setting the appliance to the “Pilot” setting. Open solid fuel
lope configuration, see 9.1.1.
burning fireplaces shall be clear of ashes.
6.2.2 Pressure Gauges, shall be digital with a resolution of
7.8 Elevators—Ensure, if elevator doors are open, that there
0.1Pa(0.0004in.WC)andaccuratetowithin 61 %ofreading
are handrail barriers across the openings on each floor and the
or 60.25 Pa (0.001 in. WC), whichever is greater, and shall
elevators are locked out and not operational.
have a means of adjusting time averaging intervals. Pressure
gauges shall measure a minimum of two samples per second.
7.9 Existing Condition Hazards—Test should not be con-
Pressure gauges shall measure pressure and flow simultane-
ducted when the building is known or suspected to have
ously. Gauges shall be checked, and their accuracy verified at
potentially hazardous materials, such as but not limited to,
intervals in accordance with the manufacturer’s recommenda-
asbestos, lead, or mold, untilAuthority Having Jurisdiction has
tions. Follow manufacturers’recommendations for field check
approved the use of a pressurization/depressurization test.
procedures.
7.10 Egress—When the building is subject to induced
6.2.3 For each test fan configuration, airflow-measuring
pressures, exterior doors have the ability to burst open if not
devices shall be accurate to within 65 % of reading. Test fans
locked and secured. All egress access points shall be clearly
shall be checked, and their accuracy verified at intervals in
marked with signage indicating the danger and that a test is in
accordance with the manufacturer’s recommendations. Follow
progress.
the manufacturer’s recommendations for field inspection pro-
cedures.
7.11 This section describes hazards related to performing
6.2.4 Temperature-Measuring Device—Instrument to mea-
these tests but does not purport to address all possible hazards.
sure temperature with an accuracy of 62 °C (4 °F).
Refer to 1.10 for further guidance.
7. Hazards
8. Calibration and Standardization
7.1 Personal Protective Equipment—On active construction
8.1 Pressure gauges shall be calibrated against a National
sites, the testing team personnel shall wear eye protection, hard
Institute of Standards and Technology (NIST) traceable stan-
hats, and safety shoes, and other safety equipment as required
dard over at least 16 pressures in a range from at least +250 to
by local regulations.
–250 Pa (1.0 in. WC) or to the greatest pressure used during a
7.2 Fall Protection—Testingteampersonnelshallbetrained
test. The minimum (absolute value) calibration pressures shall
in fall protection and proper equipment such as ladders, aerial
be no greater than 25 Pa (0.10 in. WC).
lifts, scissor lifts, stages, scaffolds while working at elevated
areas. 8.2 Airflow measuring devices shall be calibrated in com-
pliance with Test Method E1258 at a minimum of three flow
7.3 Noise—Hearing protection shall be available to testing
rates where one is above or within 10 % of the maximum flow
team personnel exposed to fan noise.
measured during the test and one is below or within 10 % of
7.4 Equipment Guards—Air moving equipment shall have
the minimum flow measured during the test. Calibration at
proper guards or cages to house the fan or blower and to
each of these three flow rates shall be performed at three
prevent access to any moving parts of the equipment.
backpressures (induced pressures) where one calibration point
7.5 Safety, Security, and Fire—Consideration shall be given is above or within 10 % of the maximum backpressure mea-
for adequate security and fire protection measures during sured and one is below or within 10 % of the minimum
testing. This would include, but not be limited to, security for backpressure measured.
E3158 − 18
8.3 Digital pressure gauges and test fans are permitted to be (5) Determine building preparations required for inten-
calibrated separately and used interchangeably if they meet the tional openings based on 9.1.5.
requirements of 6.2.3. (6) Determine whether the HVAC systems can be set as
required for the test.
9. Procedure
9.2 Coordinatethetestwiththebuildingowner,manager,or
authorized representative.
9.1 Establish Test Objectives—Determine the specified air
leakage rate and any other associated information required 9.2.1 Identify dates for conducting the test when the follow-
based on the test specifications located within the construction ing requirements can be met:
documents for the project. If not specified, clarification is
9.2.1.1 Lowest occupancy rates are expected, for example,
required from the client or the entity who has requested the test
weekends, holidays, and evenings.
to be conducted.
9.2.1.2 The owner or their representative with authorized
9.1.1 Determine the configuration of the envelope to be
access to all spaces in the test envelope shall be present.
tested, it can be either/or and or both:
9.2.1.3 Person authorized by the building owner or their
9.1.1.1 Building envelope (HVAC-related openings ex-
representative to set mechanical equipment to the mode re-
cluded).
quired for the test shall be present (for example, place
9.1.1.2 Operational envelope (building envelope and motorized dampers in the closed position, de-energize exhaust
HVAC-related openings included). and dedicated make-up air fans, and turn off required combus-
tion appliances).
9.1.2 Identify whether the test is for:
9.2.1.4 Person authorized by the building owner or their
9.1.2.1 A single zone, two or more subsections tested as a
representative to reset breakers if need be.
single zone, or isolated subsections tested independently.
9.2.2 Informthebuildingcontactpersonthatthetestmaybe
9.1.3 Three conditions are available when conducting the
canceled due to high wind speeds, gusting winds, or large
test:
indoor/outdoor temperature differences.
9.1.3.1 Pressurization only.
9.2.3 Arrange Security Procedures—Develop a security
9.1.3.2 Depressurization only.
plan to address security issues, identify safety, security, and
9.1.3.3 Pressurization and depressurization with the results
privacy concerns, and identify any areas where interior doors
averaged.
cannot be opened under any circumstances or opening doors
9.1.4 Identify whether the test will be conducted using:
may be a safety, privacy, or security issue.
9.1.4.1 The regression method,
9.3 Building or Envelope Preparation—Prior to preparing
9.1.4.2 Single-point method, or
thebuildingfortesting,determineifweatherconditionswillbe
9.1.4.3 The two-point method.
likelytoprohibittesting.Conditionsshallmeetrequirementsin
9.1.5 Identify the boundaries of the envelope that shall be
Section 10. High winds, gusty winds, and a combination of a
tested from 9.1.1.
tall building and large indoor-outdoor temperature differential,
9.1.5.1 Review available construction documents, including
are factors which may prohibit testing. (See X1.3 to X1.5.2.)
but not limited to, architectural drawings and mechanical
9.3.1 Building Envelope Test (HVAC-related openings ex-
schedules.
cluded):
9.1.5.2 In narrative or on floor plans, identify the location of
9.3.1.1 Windows and exterior doors shall be closed and
the walls, floors, ceilings, and roof assemblies bounding the
latched or locked. Interior partition doors to adjoining portions
test envelope.
within the test envelope shall be open.
(1) Make a list of identified ancillary spaces to adopt into a
9.3.1.2 From the list of intentional openings created in
testplansuchas,butnotlimitedto,mechanicalrooms,elevator
9.1.5, prepare the openings as determined and record how the
equipment rooms, loading docks, crawlspaces, basements,
openings were prepared. Note any observed deviations from
service tunnels, and attics.
the list.
(2) Include an ancillary space within the test envelope if it
9.3.2 Operational Envelope Test (building envelope and
is thermally separated from outdoors (for example, by assem-
HVAC-related openings included):
blies that include insulation and continuous air barriers) and is
9.3.2.1 Windows and exterior doors shall be closed and
not thermally separated from adjoining indoor portions of the
test envelope. latched or locked. Interior partition doors shall be in their
regular operable positions, as they would be during normal
(3) Do not include an ancillary space within the test
envelope if it is thermally separated from all adjoining portions occupancy of the building.
of the test envelope and is vented to the exterior by passive 9.3.2.2 From the list of intentional openings created in 9.1.5
openings that do not include motorized or gravity dampers. prepare the openings as determined and record how the
(4) Many older commercial, institutional, and industrial openings were prepared. Note any observed deviations from
buildings have separate mechanical rooms that contain boilers the list.
connected to multistory chimneys; these spaces often include
NOTE 3—In the case of a Multi Unit Residential Building (MURB),
passiveorfanpoweredmake-upairinlets.Inthiscase,treatthe
individual suite doors off the main corridors would remain closed, and the
boiler room as a separate space which is outside the test
doors located within the individual suites would remain open during the
envelope. Operational Envelope Test.
E3158 − 18
NOTE 4—Air handlers and fans that were not de-energized may have an
9.3.2.3 Determine how the airflow needed to conduct the
adverse effect on the test and may be de-energized to enable testing.
test will be provided and measured at the test site.
9.3.3 Determine whether the building is ready to be tested: 9.3.3.7 Confirm that effective distribution of test airflow is
9.3.3.1 Determine if weather conditions will be likely to meeting single zone requirements within the test envelope.
prohibit testing.
NOTE 5—Interior doors may remain closed if it has been demonstrated
9.3.3.2 Inspect the building to determine whether the des-
that closing them has insignificant impact on the test result (for example,
ignatedtestenvelopeiscompletefortestinginaccordancewith
pressure monitoring demonstrates that the space meets single zone
requirements). Interior doors may also be closed to manage airflow so that
9.1.5. Record any HVAC-related openings found in the build-
the single zone condition is achieved.
ing that were not identified in 9.1.5 and the status of associated
fans, dampers, and temporary sealing during the test. 9.4 Deploy Test Equipment:
9.3.3.3 Fill dry plumbing traps. 9.4.1 Envelope Pressure Measurements—Place pressure
9.3.3.4 Turn off all combustion equipment, where practical, gauges, sensing tubes, and electronic data acquisition equip-
identified in Table 1 and document any combustion equipment ment to measure the envelope pressure.
which cannot be turned off. 9.4.1.1 Envelope pressure measurements shall be made
9.3.3.5 Turn off all exhaust and make-up air fans. across one or more walls. When made across more than one
9.3.3.6 Turn off all air handlers and fans identified to be wall, the pressure taps shall be connected to a manifold, in
de-energized from Table 1 developed in 9.1.5. order to create a single exterior pressure measurement or
TABLE 1 Building Preparation for Test Boundary
Operational Envelope
Building Envelope
Intentional Openings (building envelope and HVAC-related
(HVAC-related openings excluded)
openings included)
Interior doors, hatches, and operable windows inside the test envelope, Open Closed & latched
A
which are closed during normal building operation
Interior fire doors within the test envelope Open Open
Interior common stairwell doors within the test envelope Open Open
Fire Dampers Remain as found Remain as found
Windows, doors, skylights, and hatches in the bounding envelope Closed and latched Closed and latched
Windows, doors, hatches, and operable windows in ancillary spaces as Treat in accordance with 9.1.5.2(1) Treat in accordance with 9.1.5.2(1)
identified in section 9.1.5.2(1)
Dryer doors and air handler access panels Closed and latched Closed and latched
Vented combustion appliance Off, unable to fire Off, unable to fire
Pilot light As found As found
Chimney or outlet for vented combustion device in a separate As found As found
mechanical room
B,C
B-vent or other insulated chimney serving a vented combustion appliance Sealed As found
located within the test envelope
Solid fuel appliances (fireplaces, wood burning stoves, pellet stoves) No fires; dampers closed; chimney No fires; dampers closed
B,C
sealed
Exhaust, outdoor air, make-up air fans, air handlers that serve areas Off Off
inside and outside the test envelope
Clothes dryers Off Off
B,C
Air intake inlet with motorized dampers Dampers closed and sealed Dampers closed
B,C
Air intake inlet with gravity dampers Sealed As found
B,C
Air intake inlet with no dampers Sealed Open unless fan(s) serving inlet is
operated greater than 8000 h per
B,C
year, then sealed
B,C
Exhaust or relief air outlet with motorized dampers Dampers closed and sealed Dampers closed
B,C
Exhaust or relief air outlet with gravity dampers Sealed As found
B,C
Exhaust or relief air outlet with no damper Sealed Open unless fan serving outlet is
operated greater than 8000 h per
B,C
year, then sealed
B,C
Active or passive smoke control systems - air reliefs and intakes Sealed As found
B,C
Intended powered or non-powered openings for vented shafts/stairwells Sealed As found
B,C
Waste or linen handling systems and equipment Sealed at rooftop chute vent Rooftop chute vent – open,
opening.
chute intake doors – closed,
chute intake room and chute
discharge room doors – closed and
latched,
fire dampers - left as found
B,C B,C
Clothes dryer outlets Sealed As found; sealed if dryers are not yet
installed
B,C B,C
Exhaust, outdoor air, or make-up air fan that runs >8000 h per year Sealed Sealed
B,C B,C
Ductwork that serves areas inside and outside the test envelope Sealed at supply and return Sealed at supply and return
Floor drains and plumbing Traps filled Traps filled
A
Interiordoors,hatches,andoperablewindowsshallbeleftopenifclosingthemsignificantlyrestrictsproperdistributionofpressuredifferentialsacrossthetestenvelope.
B
Sealed means that an opening has been temporarily masked airtight (for example, covered with self-adhering plastic film, taped polyethylene film, or rigid board stock).
See Appendix X1.
C
If the test result meets the passing criteria for the method used, then the building is deemed to pass even if not all of the HVAC-related openings were sealed during
the test.
E3158 − 18
measured individually and the resulting multiple measure- 10.1.3 Unadjusted Envelope Pressures and Flow
ments averaged arithmetically. Exterior pressure taps shall be Measurements—Measure and record the airflows through all
mounted within 0.5 m vertically of grade level, in contact with
operating test fans for a series of at least ten approximately
the exterior wall of the building, and within1mofthe
equally spaced unadjusted envelope pressures. Each unad-
horizontalcenterofthewall.Exteriorpressuretapsshallnotbe
justed envelope pressure and its corresponding flow measure-
moved vertically in order to locate the neutral pressure level to
ments from all fans shall occur within 20 s of each other. Each
satisfy the requirements in Eq 1. See Appendix X1 for further
induced envelope pressure shall be averaged over a minimum
recommendations.
of two times the length of the equal length intervals in 10.1.1.
9.4.2 Test Fans—Install test fans in exterior door or window
Thereshallbeatleasta25Pa(0.1in.WC)differentialbetween
openings.Followmanufacturer’sinstructionsforsettinguptest
the lowest and highest induced envelope pressures. Calculate
equipment. During windy conditions, set up the fan in a
the minimum induced envelope pressure using the following
sheltered or guarded location. Locate test fans so that a single
equation:
zone condition is created. See Appendix X1.
P
stack
9.4.3 Internal Induced Pressure Uniformity
P $ Max P 110xSTDev P , ,10 Pa
S ~ ! D
induced,min ? base,pre? base,pre
Measurements—Place pressure gauges and sensing tubes to
(1)
measure the maximum air pressure differentials between dif-
ferent sections of the test envelope.
where:
P = the minimum induced envelope pressure that
NOTE 6—For example, significant pressure differentials can exist
induced,min
between different sections of the test envelope if there are barriers to may used in the test analysis,
airflow (for example, walls or floors with either no intentional openings or
P = the pre-test baseline envelope pressure, and
base,pre
intentional openings that have a small enough area that the expected
P = the total calculated stack pressure given by Eq
stack
airflow through them will induce significant pressure drop).
2.
9.4.3.1 In the case of buildings without interior restrictions,
P 5 abs~ρ 2 ρ !·g·h (2)
stack out in
such as warehouses or buildings with central atria, no mea-
surements are required to confirm the uniform internal pres-
where:
sure. In buildings consisting of multiple zones connected by 2
ρ = inside air density (kg/m ) given by Eq A2.1,
in
2 2
m (21.5 ft ) openings (or smaller), measurements shall be
ρ = outside air density (kg/m ) given by Eq A2.2,
out
made to determine, and if a single zone condition is achieved.
g = acceleration of gravity as 9.81 m/s , and
9.4.3.2 Inmultistorybuildings,measurementsshallbemade
h = height of building (m), measured from grade up to
every ten stories and include the top floor, bottom floor, and
highest portion of the test envelope.
middle floor at a minimum. If all the rooms in a test envelope
2 10.1.4 Under windy conditions (wind speeds of 20 km/h
are interconnected with 2 m openings (or larger) and total test
(12 mph) or greater from the nearest airport weather station or
fanairflowatthehighestinducedtestpressureislessthan2800
measuredatthesite)itisrecommendedtorepeatusingalonger
L/s(6000CFM),thenpressureuniformitycanbeassumed,and
pre-test baseline. In no instance shall the induced envelope
no pressure uniformity measurements are required. These
pressure be lower than 10 Pa (0.04 in. WC) or greater than
measurements will be used to inform the test technician and
100 Pa (0.40 in. WC). For a test to be valid, the absolute value
allow them to take measures to maintain single zone pressure
of the largest induced envelope pressure shall be greater than
conditions during the test. See Appendix X1.
0.90 times the absolute value of the specified reference
pressure.
10. Calculation or Interpretation of Results
10.1.5 Maintain Single Zone Condition—Pressure differ-
10.1 Collect and Analyze Data for Multi-Point Regression
ences within the test envelope shall be measured and recorded.
Test:
For a test point to be used in the analysis, the difference
10.1.1 Pre-test Baseline Pressure—All the test fans shall be
between the highest and lowest pressure difference within the
turned off and sealed for at least 30 s after which a pre-test
test envelope shall be no more than 610 % of the induced
baseline pressure measurement of at least 120 s duration shall
envelope pressure. Make any corrections needed to maintain a
be recorded. Baseline measurements shall be the temporal
single zone condition. Exception: if uniformity was not main-
average of the baseline data from all envelope pressure
tained within 10 % during a test, the building may be deemed
locations. When analyzing the data, use the same envelope
to pass if the test specification is met when the results are
pressure locations for all baseline envelope pressures and
analyzed using only the building envelope pressure measure-
unadjusted envelope pressures. Divide the baseline into 12
ments made at the location of the induced envelope pressure
equal length intervals. Calculate the temporal average of each
differential with the smallest absolute value.
interval and the standard deviation of these averages. The
baseline standard deviation (STDev (P )) is used in Eq 1 10.1.6 Post-test Baseline Pressure—Allthetestfansshallbe
base,pre
turned off and sealed for at least 30 s, after which a post-test
to calculate the minimum allowable induced envelope pres-
sure. baseline pressure measurement of at least 120 s duration shall
10.1.2 Measure and record the pre-test indoor and outdoor be recorded. Baseline measurements shall be the temporal
average of the baseline data averaged over all envelope
air temperature and wind speed. Determine the site altitude
above mean sea level within 100 m (300 ft). pressure locations.
E3158 − 18
10.1.7 Pressurization and Depressurization—Repeat 10.1.1 and sealed for at least 30 s or until the building envelope
through 10.1.6 for each required test mode (depressurization or pressures stabilize, after which a baseline pressure measure-
pressurization, or both). When performing both pressurization ment of at least two times the length of the equal length
and depressurization measurements, record the pressurization intervals in 10.2.1 shall be recorded. Baseline measurements
and depressurization data separately including all preliminary shall be the temporal average of the baseline data from all
environmental measurements and baseline readings as if per- envelope pressure locations.
forming two separate or individual tests.
10.2.3 Alternately baseline measurements may be collected
10.1.8 Data Analysis and Calculations:
before and after the replicate set of induced envelope pressure
10.1.8.1 Data shall be analyzed in accordance with Annex tests described in 10.2.5 as follows:
A1 (un-weighted regression).
10.2.3.1 Pre-test Baseline Pressure—As defined in 10.2.1.
10.1.9 For each test, if the calculated pressure exponent, n,
10.2.3.2 Post-test Baseline—All the test fans shall be turned
is less than 0.45 or greater than 1.05, the test is invalid. If n is
off and sealed for at least 30 s, after which a post-test baseline
less than 0.5 or greater than 0.9, check test envelope setup to
pressure measurement of the same duration as the pre-test
determine whether openings have inadvertently opened or
baseline shall be recorded. Baseline measurements shall be the
closed during the test. If a problem is found, correct the
temporal average of the baseline data averaged over all
problem and retest. See Appendix X1 for discussion of this
envelope pressure locations.
issue.
10.2.4 Measure and record the indoor and outdoor tempera-
10.1.10 If specified to use r , the value shall be no less than
ture and wind speed. Determine the site altitude above mean
0.98. If r is less than 0.98, review the testing procedure, data,
sea level within 300 ft (100 m).
and envelope setup, to eliminate any problems.Take corrective
10.2.5 Induced Envelope Pressure and Flow
action as needed. See Appendix X1 for discussion of this issue
Measurements—The specified reference pressure shall be as
and calculations.
determined in 9.1. If no induced test pressure is specified, test
10.1.11 The test is not considered valid if the calculated
at 75 Pa (0.30 in. WC). Measure and record the airflows
flow at the specified reference pressure as determined in
through all operating test fans for at least five replicate induced
construction documents is:
envelope pressures. Each induced envelope pressure and its
10.1.11.1 Greater than the specified air leakage rate;
corresponding flow measurement shall occur within 20 s of
10.1.11.2 Exhausted from or supplied to the test envelope,
each other. Each induced envelope pressure shall be averaged
and the induced envelope pressure is less than 90 % of the
over a minimum of two times the length of the equal length
specified reference pressure;
intervals in 10.2.1. Airflow measurements shall be the sum of
10.1.11.3 Less than or equal to the specified air leakage rate
the airflows through all operating test fans. For the Repeated
and the 95 % confidence interval is greater than 8 %, and the
Single Point test, induced, min is the reference envelope
sum of the test result and the 95 % CI is greater than the
pressure of the specified air leakage rate. It shall be no lower
specified air leakage rate.
than 10 Pa (0.04 in. WC) and no greater than 100 Pa (0.40 in.
10.1.12 The test is considered valid if the calculated flow at
WC) and is calculated using the minimum induced envelope
the specified reference pressure as determined in the construc-
pressure using Eq 1. Under windy conditions, if this condition
tion documents is:
is not met, it is recommended to repeat using a longer pre-test
10.1.12.1 Less than or equal to the specified air leakage rate
baseline (see Appendix X1 for additional guidance).
and the 95 % confidence interval (CI) of the flow at the
10.2.6 Maintain Single Zone Condition—Pressure differ-
specified reference pressure is less than or equal to 8 % of the
ences within the test envelope shall be measured and recorded.
specified air leakage rate.
For a test point to be used in the analysis, the difference
10.1.13 Test result will be reported in specified units along
between the highest and lowest pressure difference within the
with 95 % CI.
test envelope shall be within 10 % of the induced envelope
pressure. Make any corrections needed to maintain single zone
10.2 Collect and Analyze Data for Repeated Single Point
requirements. Exception: if uniformity was not maintained
Test:
within 10 % during a test, the building may be deemed to pass
10.2.1 Pre-test Baseline Pressure—All the test fans shall be
if the test specification is met when the results are analyzed
turned off and sealed for at least 30 s after which a pre-test
using only the building envelope pressure measurements made
baseline pressure measurement of at least 120 s duration shall
at the location with the induced envelope pressure differential
be recorded. Baseline measurements shall be the temporal
with the smallest absolute value.
average of the baseline data from all envelope pressure
10.2.7 Pressurization and Depressurization—Repeat 10.2.1
locations. When analyzing the data, use the same envelope
pressure locations for all baseline envelope pressures and through 10.2.6 for each required test mode (depressurization or
pressurization, or both). When performing pressurization and
induced envelope pressures. Divide the baseline into 12 equal
depressurization measurements, record the pressurization and
length intervals. Calculate the temporal average of each inter-
depressurization data separately, including all preliminary
val and the standard deviation of these averages. The baseline
environmental measurements and baseline readings as if you
standard deviation (STDev (P )) is used in Eq 1 to
base,pre
were performing two separate or individual tests.
calculate the minimum allowable induced envelope pressure.
10.2.2 Baseline Pressure—Before each measurement at the 10.2.8 Data Analysis and Calculations—If the airflow re-
induced envelope pressure, all the test fans shall be turned off quiredtomeetthespecifiedreferencepressureasdeterminedin
E3158 − 18
9.1 is exhausted from or supplied to the test envelope, and the pressure measurement of the same duration as the pre-test
induced envelope pressure is less than 90 % of the specified baseline shall be recorded. Baseline measurements shall be the
reference pressure, the test is not considered valid. temporal average of the baseline data averaged over all
10.2.9 Data shall be analyzed in accordance with AnnexA4 envelope pressure locations.
or the specified reference pressure if different than 50 to 75 Pa
10.3.4 Induced Envelope Pressures and Flow
(0.20 to 0.30 in. WC). Please refer to A1.2 for calculations.
Measurements—Measure and record the airflows through all
operating test fans for two induced envelope pressures, a
NOTE 7—If the pre-test and post-test baseline alternate is chosen, there
primary and secondary induced pressure (P1and P2). If P1 is
are two baseline measurements for the test: one before the entire set of
replicate induced envelope pressures, and one after. In this case use the
not specified, assume 75 Pa (0.03 in. WC) for P1.Aminimum
average of the pre-test and post-test baseline measurements as the average
of five replicate measurements of pressure and airflow at the
baseline for all replicate measurements at the induced envelope pressure.
primary induced pressure and the secondary induced pressure
10.2.10 For a test envelope to pass, each induced envelope
are required. Ensure enough time has been given between
pressureshallbewithin10 %ofthespecifiedinducedenvelope
readings to ensure the induced pressure has stabilized. Each
pressure.
inducedenvelopepressureanditscorrespondingflowmeasure-
10.2.11 Document if the calculated flow at the specified
ment shall occur within 20 s of each other. Calculate the
reference pressure is:
minimum induced envelope pressure using Eq 1. For the
10.2.11.1 Greater than the specified air leakage rate;
Repeated Two-point test P , min is P2, the secondary
induced
10.2.11.2 Less than or equal to the specified air leakage rate
induced envelope pressure. Under windy conditions, if this
and the overall uncertainty Eq 3 in 12.1 is less than or equal to
conditionisnotmet,itisrecommendedtorepeatusingalonger
8 % of the specified air leakage rate;
pre-test baseline (see Appendix X1 for additional guidance).
10.2.11.3 Less than or equal to the specified air leakage rate
P2 shall not be greater than one-third of the primary induced
and the overall uncertainty Eq 3 in 12.1 is greater than 8 % and
pressure P1. Therefore, the sequence of testing shall be the
thesumofthetestresultandtheoveralluncertaintyislessthan
primary induced pressure, P1 followed by the secondary
or equal to the specified air leakage rate;
induced pressure P2, in order to establish P2. Each induced
10.2.11.4 Less than or equal to the specified air leakage rate
envelope pressure shall be averaged over a minimum of two
and the overall uncertainty Eq 3 in 12.1 is greater than 8 % and
times the length of the equal length intervals in 10.3.1. Induced
the sum of the test result and the overall uncertainty is greater envelope pressures shall be no lower than 10 Pa (0.04 in. WC)
than the specified air leakage rate.
and no greater than 100 Pa (0.40 in. WC). Airflow measure-
10.2.12 Test result will be reported in specified units along mentsshallbethesumoftheairflowsthroughalloperatingtest
with the overall uncertainty.
fans.
10.3.5 Test results P1 or P2 shall be within 10 % of the
10.3 Collect and Analyze Data for Repeated Two-Point
specified reference pressure and with a calculated pressure
Test:
exponent, n, between the values of 0.45 and 1.05. If the
10.3.1 Pre-test Baseline Pressure—All the test fans shall be
primary induced envelope pressure is not within 10 % of the
turned off and sealed for at least 30 s after which a pre-test
specified reference pressure, but the pressure exponent is
baseline pressure measurement of at least 120 s duration shall
within the allowable range, the test results may be deemed as
be recorded. Baseline measurements shall be the temporal
a legitimate test. If n is less than 0.5 or greater than 0.9, check
average of the baseline data from all envelope pressure
test envelope setup to determine whether openings have
locations. When analyzing the data, use the same envelope
inadvertently opened or closed during the test. If a problem is
pressure locations for all baseline envelope pressures and
found, correct the problem and retest. (See Appendix X1 for
induced envelope pressures. Divide the baseline into 12 equal
discussion of this issue.)
length intervals. Calculate the temporal average of each inter-
val and the standard deviation of these averages. The baseline 10.3.6 Maintain Single Zone Condition—Pressure differ-
standarddeviation(STDev(P )isusedinEq1tocalculate enceswithinthetestenvelopeshallbemonitoredandrecorded.
base,pre
For a test point to be used in the analysis, the difference
the minimum allowable induced envelope pressure.
between the highest and lowest pressure difference within the
10.3.2 Baseline Pressure—Before e
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