ASTM E1827-22

Standard Test Methods for Determining Airtightness of Buildings Using an Orifice Blower Door

SIGNIFICANCE AND USE
5.1 Airtightness—Building airtightness is one factor that affects building air change rates under normal conditions of weather and building operation. These air change rates account for a significant portion of the space-conditioning load and affect occupant comfort, indoor air quality, and building durability. These test methods produce results that characterize the airtightness of the building envelope. These results can be used to compare the relative airtightness of similar buildings, determine airtightness improvements from retrofit measures applied to an existing building, and predict air leakage. Use of this standard in conjunction with Practices E1186 permits the identification of leakage sources and rates of leakage from different components of the same building envelope. These test methods evolved from Test Method E779 to apply to orifice blower doors.  
5.1.1 Applicability to Natural Conditions—Pressures across building envelopes under normal conditions of weather and building operation vary substantially among various locations on the envelope and are generally much lower than the pressures during the test. Therefore, airtightness measurements using these test methods cannot be interpreted as direct measurements of natural infiltration or air change rates that would occur under natural conditions. However, airtightness measurements can be used to provide air leakage parameters for models of natural infiltration. Such models can estimate average annual ventilation rates and the associated energy costs. Test Method E741 measure natural air exchange rates using tracer gas dilution techniques.  
5.1.2 Relation to Test Method E779—These test methods are specific adaptations of Test Method E779 to orifice blower doors. For nonorifice blower doors or for buildings too large to use blower doors, use Test Method E779.  
5.1.3 Relation to Test Method E3158—These test methods are applicable for buildings that are configured as a single zone. For testing of multi...
SCOPE
1.1 These test methods describe two techniques for measuring air leakage rates through a building envelope in buildings that may be configured to a single zone. Both techniques use an orifice blower door to induce pressure differences across the building envelope and to measure those pressure differences and the resulting airflows. The measurements of pressure differences and airflows are used to determine airtightness and other leakage characteristics of the envelope.  
1.2 These test methods allow testing under depressurization and pressurization.  
1.3 These test methods are applicable to small indoor-outdoor temperature differentials and low wind pressure conditions; the uncertainty in the measured results increases with increasing wind speeds and temperature differentials.  
1.4 These test methods do not measure air change rate under normal conditions of weather and building operation. To measure air change rate directly, use Test Method E741.  
1.5 The text of these test methods reference notes and footnotes that provide explanatory material. These notes and footnotes, excluding those in tables and figures, shall not be considered as requirements of the standard.  
1.6 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.  
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements see Section 7.  
1.8 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 Re...

General Information

• Status: Published
• Publication Date: 30-Sep-2022
• ICS: 91.010.30 - Technical aspects
• Technical Committee: E06 - Performance of Buildings
• Drafting Committee: E06.41 - Air Leakage and Ventilation Performance

Relations

• Refers: ASTM E456-13a(2022)e1 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 01-Apr-2022
• Refers: ASTM E779-19 - Standard Test Method for Determining Air Leakage Rate by Fan Pressurization
• Effective Date: 01-Jan-2019
• Refers: ASTM E3158-18 - Standard Test Method for Measuring the Air Leakage Rate of a Large or Multizone Building
• Effective Date: 01-Dec-2018
• Refers: ASTM E779-10(2018) - Standard Test Method for Determining Air Leakage Rate by Fan Pressurization
• Effective Date: 15-Jul-2018
• Refers: ASTM E456-13A(2017)e3 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 01-Oct-2017
• Refers: ASTM E456-13A(2017)e1 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 01-Oct-2017
• Refers: ASTM E631-15 - Standard Terminology of Building Constructions
• Effective Date: 01-Mar-2015
• Refers: ASTM E631-14 - Standard Terminology of Building Constructions
• Effective Date: 01-Nov-2014
• Refers: ASTM E456-13a - Standard Terminology Relating to Quality and Statistics
• Effective Date: 15-Nov-2013
• Refers: ASTM E456-13ae1 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 15-Nov-2013
• Refers: ASTM E456-13ae3 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 15-Nov-2013
• Refers: ASTM E456-13ae2 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 15-Nov-2013
• Refers: ASTM E456-13 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 15-Aug-2013
• Refers: ASTM E1258-88(2012) - Standard Test Method for Airflow Calibration of Fan Pressurization Devices
• Effective Date: 01-Oct-2012
• Refers: ASTM E456-12e1 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 01-May-2012

Overview

ASTM E1827-22 is the Standard Test Methods for Determining Airtightness of Buildings Using an Orifice Blower Door, developed by ASTM International. This standard outlines procedures for measuring air leakage rates through building envelopes in structures configured as a single zone. By employing an orifice blower door, professionals can induce controlled pressure differences across a building envelope to assess airtightness, which directly impacts building energy efficiency, occupant comfort, indoor air quality, and durability.

Key Topics

• Purpose of Airtightness Testing: Understanding and quantifying building envelope airtightness is crucial for identifying air leakage points that affect heating/cooling loads, indoor air quality, and the overall resilience of buildings.
• Test Methods: The standard defines two main approaches:
  • Single-Point Method: Evaluates air leakage by making multiple measurements at a single pressure differential (typically 50 Pa).
  • Two-Point Method: Involves measurements at two pressure differentials, enabling more detailed analysis for use in ventilation models.
• Test Conditions: Tests are typically performed under low wind speed and small indoor-outdoor temperature differences to reduce uncertainty. Both depressurization and pressurization can be applied, depending on specific objectives.
• Test Preparation: Proper building configuration (closed or occupied), sealing of specific openings, and equipment calibration are essential for accurate results.
• Data Reporting: The standard specifies reporting requirements that include building description, test procedures, environmental conditions, air leakage rates, and uncertainties.

Applications

ASTM E1827-22 is widely used by building scientists, energy auditors, HVAC professionals, and quality control experts for:

• Energy Efficiency Evaluations: Quantifying building envelope air leakage helps architects and energy managers assess the effectiveness of construction or retrofitting measures aimed at reducing energy loss.
• Comparative Performance: Results can be used to compare the airtightness of similar buildings, evaluate improvements after repairs, and benchmark against best practices.
• Predictive Maintenance: Identifying air leakage points supports proactive maintenance and building durability by preventing moisture ingress and associated damages.
• Compliance and Certification: Supports verification for energy codes, building certifications, and green building programs that require documented proof of envelope performance.
• Ventilation System Design: Provides key input data for natural ventilation models, allowing for reliable estimation of annual ventilation rates and associated energy costs.

Related Standards

To capture a complete picture of building envelope performance and air leakage, ASTM E1827-22 is often used in conjunction with other standards:

• ASTM E1186: Practices for Air Leakage Site Detection in Building Envelopes and Air Barrier Systems - Useful for pinpointing leakage sources.
• ASTM E779: Test Method for Determining Air Leakage Rate by Fan Pressurization - The predecessor of E1827 for other blower door systems or larger buildings.
• ASTM E3158: Test Method for Measuring Air Leakage Rate of Large or Multi-zoned Buildings.
• ASTM E741: Test Method for Determining Air Change in a Single Zone by Means of a Tracer Gas Dilution - Measures actual air change rates under natural conditions.
• ISO 9972: International standard for measuring building airtightness using fan pressurization.

Practical Value

By following the procedures in ASTM E1827-22, building professionals can:

• Accurately assess and compare building airtightness
• Identify areas for improvement to reduce energy usage
• Ensure better indoor air quality and occupant comfort
• Meet building codes and certification requirements
• Support optimal ventilation design and long-term building maintenance

Keywords: ASTM E1827-22, airtightness, orifice blower door, building envelope, air leakage, energy efficiency, building performance, pressurization test, depressurization, HVAC, air infiltration, ASTM standards.

Standards Content (Sample)

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:E1827 −22
Standard Test Methods for
Determining Airtightness of Buildings Using an Orifice
Blower Door
This standard is issued under the fixed designation E1827; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
1.1 These test methods describe two techniques for measur-
Barriers to Trade (TBT) Committee.
ing air leakage rates through a building envelope in buildings
thatmaybeconfiguredtoasinglezone.Bothtechniquesusean
2. Referenced Documents
orifice blower door to induce pressure differences across the
2.1 ASTM Standards:
building envelope and to measure those pressure differences
E456Terminology Relating to Quality and Statistics
and the resulting airflows. The measurements of pressure
E631Terminology of Building Constructions
differences and airflows are used to determine airtightness and
E741Test Method for Determining Air Change in a Single
other leakage characteristics of the envelope.
Zone by Means of a Tracer Gas Dilution
1.2 These test methods allow testing under depressurization
E779TestMethodforDeterminingAirLeakageRatebyFan
and pressurization.
Pressurization
1.3 These test methods are applicable to small indoor-
E1186Practices for Air Leakage Site Detection in Building
outdoor temperature differentials and low wind pressure con-
Envelopes and Air Barrier Systems
ditions; the uncertainty in the measured results increases with
E1258Test Method for Airflow Calibration of Fan Pressur-
increasing wind speeds and temperature differentials.
ization Devices
E3158Test Method for Measuring the Air Leakage Rate of
1.4 Thesetestmethodsdonotmeasureairchangerateunder
a Large or Multizone Building
normal conditions of weather and building operation. To
measure air change rate directly, use Test Method E741.
2.2 ISO International Standard:
ISO 9972Thermal Insulation—Determination of Building
1.5 The text of these test methods reference notes and
Airtightness—Fan Pressurization Method
footnotes that provide explanatory material. These notes and
footnotes, excluding those in tables and figures, shall not be 2.3 Other Standard:
considered as requirements of the standard. ANSI/ASME PTC 19.1–1985 Part 1: Measurement
Uncertainty, Instruments, and Apparatus
1.6 The values stated in SI units are to be regarded as
standard. The values given in parentheses after SI units are
3. Terminology
providedforinformationonlyandarenotconsideredstandard.
3.1 Definitions:
1.7 This standard does not purport to address all of the
3.1.1 For definitions of general terms related to building
safety concerns, if any, associated with its use. It is the
construction used in this test methods, refer to Terminology
responsibility of the user of this standard to establish appro-
E631andforgeneraltermsrelatedtoaccuracy,bias,precision,
priate safety, health, and environmental practices and deter-
and uncertainty refer to Terminology E456.
mine the applicability of regulatory limitations prior to use.
3.2 Definitions of Terms Specific to This Standard:
For specific hazard statements see Section 7.
3.2.1 ACH ,n—the ratio of the air leakage rate at 50 Pa
1.8 This international standard was developed in accor-
(0.2 in. H O), corrected for a standard air density, to the
dance with internationally recognized principles on standard-
volume of the test zone (1/h).
ization established in the Decision on Principles for the
1 2
These test methods are under the jurisdiction of ASTM Committee E06 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Performance of Buildings and are the direct responsibility of Subcommittee E06.41 contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
on Air Leakage and Ventilation Performance. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Oct. 1, 2022. Published October 2022. Originally the ASTM website.
approved in 1996. Last previous edition approved in 2017 as E1827–11 (2017). Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
DOI: 10.1520/E1827-22. 4th Floor, New York, NY 10036, http://www.ansi.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E1827−22
3.2.2 air leakage rate, Q ,n—the total volume of air
C = flow coefficient at standard conditions, m /s
env
n 3 n 4
passing through the test zone envelope per unit of time (m /s,
(Pa)ft /min (in. H O ),
ft /min).
L = effectiveleakageareaatstandardconditions,m
(in. ),
3.2.3 airtightness, n—the degree to which a test zone
n = envelope flow exponent (dimensionless),
envelope resists the flow of air.
P = building pressure difference (see 3.2.5),
¯
P = average pressure, P , at the primary pressure
NOTE 1—ACH , air leakage rate, and effective leakage area are
1 sta
examples of measures of building airtightness.
station, Pa (in. H O),
¯
P = averagepressure, P ,atthesecondarypressure
3.2.4 blower door, n—a fan pressurization device incorpo- 2 sta
station, Pa (in. H O),
rating a controllable fan and instruments for airflow measure-
P = the reference pressure differential across the
ref
ment and building pressure difference measurement that
building envelope, Pa (in. H O),
mounts securely in a door or other opening.
P = station pressure, Pa (in. H O),
sta 2
3.2.5 building pressure difference, P, n—the pressure differ-
P = test pressure, Pa (in. H O),
test 2
ence across the test zone envelope (Pa, in. H O).
P = zero-airflow pressure before test, Pa (in. H O),
2 zero1 2
P = zero-airflow pressure after test, Pa (in. H O),
zero2 2
3.2.6 fan airflow rate, Q ,n—the volume of airflow
3 3
fan
Q = the air leakage rate, m /s (ft /min),
3 3
env
through the blower door per unit of time (m /s, ft /min).
¯
Q = average air leakage rate, Q , at the primary
env1 env
3 3
3.2.7 nominal airflow rate, Q ,n—the flow rate indicated
pressure station, m /s (ft /min),
nom
¯
by the blower door using the manufacturer’s calibration
Q = average air leakage rate, Q , at the secondary
env2 env
3 3 3 3
coefficients (m /s, ft /min). pressure station, m /s (ft /min),
Q = fan airflow rate (see 3.2.6),
fan
3.2.8 orifice blower door, n—ablowerdoorinwhichairflow
Q = nominal airflow rate (see 3.2.7),
nom
rate is determined by means of the pressure drop across an
T = temperature, °C (°F),
orifice or nozzle.
t = value from a two-tailed student t table for the
95% confidence level,
3.2.9 precisionindexoftheaverage,n—thesamplestandard
δn = measurement uncertainty of the envelope flow
deviationdividedbythesquarerootofthenumberofsamples.
exponent (dimensionless),
3.2.10 pressure station, n—a specified induced change in
3 3
V = volume of the test zone, m (ft ),
zone
the building pressure difference from the initial zero-flow
δQ = measurement uncertainty of the average air
env
building pressure difference (Pa, in. H O). 3 3
leakage rate, m /s (ft /min),
3 3
δQ = the measurement uncertainty of Q ,m /s (ft /
3.2.11 single zone, n—a space in which the pressure differ-
50 50
min),
ences between any two places, as indicated on a manometer,
3 3
δQ = estimated bias of the flow rate, m /s (ft /min),
differ by no more than 2.5 Pa (0.01 in. H O) during fan
bias
δQ = estimated bias of the flow rate at the primary
pressurizationatabuildingpressuredifferenceof50Pa(0.2in. bias1
3 3
pressure station, m /s (ft /min),
H O)andbynomorethan5%ofthehighestbuildingpressure
δQ = estimated bias of the flow rate at the secondary
bias2
difference achieved.
3 3
pressure station, m /s (ft /min),
NOTE 2—A multiroom space that is interconnected within itself with
δQ = precision index of the average measured flow
precision
3 3
door-sizedopeningsthroughanypartitionsorfloorsislikelytosatisfythis
rate, m /s (ft /min),
3 3 3
criterion if the fan airflow rate is less than 3 m /s (6×10 ft /min) and the
δQ = precision index of the average measured flow
prec1
test zone envelope is not extremely leaky.
3 3
rate at the primary pressure station, m /s (ft /
3.2.12 test zone, n—abuildingoraportionofabuildingthat
min),
is configured as a single zone for the purpose of this standard.
δQ = precision index of the average measured flow
prec2
rate at the secondary pressure station, m /s
NOTE 3—For detached dwellings, the test zone envelope normally
(ft /min),
comprises the thermal envelope.
δP = measurement uncertainty of the average mea-
3.2.13 test zone envelope, n—thebarrierorseriesofbarriers
sured pressure differential across the building
between a test zone and the outdoors.
envelope, Pa (in. H O),
δP = estimatedbiasofthepressuredifferentialacross
bias
NOTE 4—The user establishes the test zone envelope at such places as
the building envelope, Pa (in. H O),
basements or neighboring rooms by choosing the level of resistance to
airflowbetweenthetestzoneandoutdoorswithsuchmeasuresasopening δP = estimatedbiasofthepressuredifferentialacross
bias1
or closing windows and doors to, from, and within the adjacent spaces.
the building envelope at the primary pressure
station, Pa (in. H O),
3.2.14 zero-flow building pressure difference, n—the natural 2
δP = estimatedbiasofthepressuredifferentialacross
building pressure difference measured when there is no flow bias2
the building envelope at the secondary pressure
through the blower door.
station, Pa (in. H O),
3.3 Symbols—The following is a summary of the principal
symbols used in these test methods:
Alt = altitude at site, m (ft),
Historically, a variety of other units have been used.
E1827−22
would occur under natural conditions. However, airtightness
δP = precision index of the average measured pres-
precision
measurements can be used to provide air leakage parameters
sure differential across the building envelope,
for models of natural infiltration. Such models can estimate
Pa (in. H O),
average annual ventilation rates and the associated energy
δP = precision index of the average measured pres-
prec1
sure differential across the building envelope at costs. Test Method E741 measure natural air exchange rates
using tracer gas dilution techniques.
the primary pressure station, Pa (in. H O),
δP = precision index of the average measured pres-
prec2 5.1.2 RelationtoTestMethodE779—Thesetestmethodsare
sure differential across the building envelope at
specific adaptations of Test Method E779 to orifice blower
the secondary pressure station, Pa (in. H O),
2 doors.Fornonorificeblowerdoorsorforbuildingstoolargeto
δV = measurement uncertainty of the zone volume,
zone use blower doors, use Test Method E779.
3 3
m (ft ),
5.1.3 Relation to Test Method E3158—These test methods
µ = dynamic viscosity, kg/m·s (lbm/ft·hr),
3 3 are applicable for buildings that are configured as a single
ρ = air density, kg/m (lbm/ft ), and
zone. For testing of multi-zone buildings, use Test Method
ρ = air density at which the calibration values are
cal
3 3
E3158.
valid, kg/m (lbm/ft ).
5.2 Single-Point Method—Use this method to provide air
4. Summary of Test Methods
leakage estimates for assessing improvements in airtightness.
4.1 Pressure versus Flow—These test methods consist of
5.3 Two-Point Method—Use this method to provide air
mechanical depressurization or pressurization of a building
leakage parameters for use as inputs to natural ventilation
zoneduringwhichmeasurementsoffanairflowratesaremade
models. The two-point method uses more complex data analy-
atoneormorepressurestations.Theairleakagecharacteristics
sis techniques and requires more accurate measurements
of a building envelope are evaluated from the relationship
(Tables X1.1 and X1.2) than the single-point method. It can be
between the building pressure differences and the resulting
usedtoestimatethebuildingleakagecharacteristicsatbuilding
airflow rates. Two alternative measurement and analysis pro-
pressure differences as low as 4 Pa (0.016 in. H O).Avariety
cedures are specified in this standard, the single-point method
of reference pressures for building envelope leaks has been
and the two-point method.
used or suggested for characterizing building airtightness.
4.1.1 Single-Point Method—This method provides air leak-
These pressures include 4 Pa (0.016 in. H O), 10 Pa (0.04 in.
age estimates by making multiple flow measurements near 2
H O), 30 Pa (0.12 in. H O), and 50 Pa (0.2 in. H O). The
2 2 2
P =50 Pa (0.2 in. H O) and assuming a building flow
1 2
ASHRAE Handbook of Fundamentals uses 4 Pa.
exponent of n=0.65.
4.1.2 Two-Point Method—This method provides air leakage
5.4 Depressurization versus Pressurization—Depending on
estimates by making multiple flow measurements near
the goals of the test method, the user may choose depressur-
P =50Pa (0.2 in. H O) and near P =12.5 Pa (0.05 in. H O)
1 2 2 2
ization or pressurization or both. This standard permits both
that permit estimates of the building flow coefficient and flow
depressurization and pressurization measurements to compen-
exponent.
sate for asymmetric flow in the two directions. Depressuriza-
tionisappropriatefortestingthebuildingenvelopetightnessto
5. Significance and Use
include the tightness of such items as backdraft dampers that
5.1 Airtightness—Building airtightness is one factor that
inhibit infiltration but open during a pressurization test. Com-
affects building air change rates under normal conditions of
bining the results of depressurization and pressurization mea-
weatherandbuildingoperation.Theseairchangeratesaccount
surements can minimize wind and stack-pressure effects on
for a significant portion of the space-conditioning load and
calculatingairtightnessbutmayoverestimateairleakagedueto
affect occupant comfort, indoor air quality, and building
backdraft dampers that open only under pressurization.
durability.Thesetestmethodsproduceresultsthatcharacterize
5.5 Effects of Wind and Temperature Differences—Calm
the airtightness of the building envelope. These results can be
winds and moderate temperatures during the test improve
used to compare the relative airtightness of similar buildings,
precisionandbias.Pressuregradientsovertheenvelopecaused
determine airtightness improvements from retrofit measures
by inside-outside temperature differences and wind cause bias
applied to an existing building, and predict air leakage. Use of
in the measurement by changing the building pressure differ-
this standard in conjunction with Practices E1186 permits the
ences over the test envelope from what would occur in the
identification of leakage sources and rates of leakage from
absenceofthesefactors.Windalsocausespressurefluctuations
differentcomponentsofthesamebuildingenvelope.Thesetest
that affect measurement precision and cause the data to be
methods evolved from Test Method E779 to apply to orifice
autocorrelated.
blower doors.
5.1.1 Applicability to Natural Conditions—Pressures across
6. Apparatus
building envelopes under normal conditions of weather and
building operation vary substantially among various locations
6.1 Blower Door—An orifice blower door (see Fig. 1).
on the envelope and are generally much lower than the
pressuresduringthetest.Therefore,airtightnessmeasurements 6.2 Measurement Precision and Bias—Appendix X1 lists
using these test methods cannot be interpreted as direct recommended values for the precision and bias of the mea-
measurements of natural infiltration or air change rates that surements of airflow, pressure difference, wind speed, and
E1827−22
6.8 Wind Pressure Averaging System (optional)—A system
to reduce the effect of pressure variations from static probes
outside the building envelope and of pressure fluctuations over
time. It shall have a manifold that accepts multiple tubes of
equal lengths sufficient to reach representative surfaces of the
building.
7. Hazards
7.1 Eye Protection—Glass should not break at the building
pressure differences normally applied to the test structure.
However, for added safety, adequate precautions such as the
use of eye protection should be taken to protect the personnel.
7.2 Safety Clothing—Use safety equipment required for
general field work, including safety shoes and hard hats.
7.3 Equipment Guards—The air-moving equipment shall
have a proper guard or cage to house the fan or blower and to
prevent accidental access to any moving parts of the equip-
FIG. 1Blower Door Assembly
ment.
7.4 Noise Protection—Make hearing protection available
temperature to obtain the precision and bias for test results for personnel who must be close to the noise that may be
generated by the fan.
described in 11.2 for the single-point method and 11.3 for the
two-point method.
7.5 Debris and Fumes—The blower or fan forces a large
6.2.1 Fan with Controllable Flow—The fan shall have
volume of air into or out of a building while operating.
sufficient capacity to generate at least a 40 Pa (0.20 in. H O)
Exercisecarenottodamageplants,pets,occupants,orinternal
building pressure difference in the zone tested and be control-
furnishings due to influx of cold or warm air. Exercise similar
lable over a calibrated range sufficient to generate the building
cautions against sucking debris or exhaust gases from fire-
pressure differences required by this standard.
places and flues into the interior of the building. Active
combustion devices require a properly trained technician to
NOTE 5—For testing most single family houses, a range of airflows
3 3 3 3
from 0.1m /s to 3 m /s (200ft /min to 6000 ft /min) is usually adequate.
shut them off or to determine the safety of conducting the test.
6.2.2 Airflow Measurement—The procedure for calibrating
8. Procedure
the airflow measurement device shall be provided with the
instrument together with estimates of the precision and bias of
8.1 Establish Test Objectives—Determine the configuration
the instrument. The air density (ρ ) for which any calibration
cal of the building envelope to be tested. The most common
equations or tables were calculated shall be reported. If the
objectives are to evaluate the effect of construction quality on
instrument automatically compensates for changes in air
leaks in the building envelope (hereafter called closed) or to
density, the instructions shall note this fact.
assess the envelope’s impact on natural air change rates
6.2.3 Pressure Measurement—Theprocedureforcalibrating
(hereafter called occupied). Choose the envelope condition
the pressure measurement device shall be provided with the
appropriate to the objective.
instrument together with estimates of the precision and bias of
8.1.1 Residential Construction—Use Table 1 to determine
the instrument.
the recommended test envelope conditions for residential
construction.
6.3 Wind Speed Measurement (two-point method only)—A
8.1.1.1 Closed—Close all operable openings and seal other
device to measure the site wind speed.
intentional openings to evaluate envelope airtightness without
6.4 Air Temperature Measurement—Athermometer or elec-
including intentional openings.
tronic sensor with readout.
8.1.1.2 Occupied (default)—Leave all operable openings in
6.5 Barometer (optional)—A device to measure the site
the conditions typical of occupancy to assess the envelope’s
barometric pressure.
effect on natural air change rates. This shall be the default
6.6 Data Acquisition (optional)—Automated data acquisi- option if no compelling reason exists to choose 8.1.1.1.
tion equipment to record (in machine readable form) data on
8.2 Ancillary Measurements:
airflow and building pressure differences within 10 s of each
8.2.1 Environmental Measurements—Measure and record
otherand(optionally)temperature,windspeed,andbarometric
the wind speed 2 m (6 ft) above the ground and 10 m (30 ft)
pressure.
upwindfromthebuilding,whenpractical,outsidetemperature,
6.7 Pressure and Flow Measurement System (two-point and inside temperature at the beginning of each fan pressur-
method only)—The flow and pressure measurement system izationtest.Circleorotherwiseemphasizethereadingsifwind
shall measure flow and pressure differentials within 20 s of speed is greater than 2 m/s (4 mph) or outside temperature is
each other. outside the bounds of 5°C to 35°C (41°F to 95°F).
E1827−22
TABLE 1 Recommended Test Envelope Conditions
Envelope Conditions
Building Component
Occupied (Default) Closed
Vented combustion appliance Off Off
Pilot light As found As found
Flue to nonwood combustion appliance Sealed No preparation
Flues for fireplaces and wood stoves with dampers Closed Closed
Flues for fireplaces and wood stoves without dampers Ashes removed Ashes removed
Fireplace and wood stove doors and air inlet dampers Closed Closed
Fireplace without firebox doors No preparation No preparation
Furnace room door for furnace outside test zone Closed Closed
Combustion air intake damper for wood stove or fireplace Closed Closed
Make up air intake damper for furnace inside test zone Sealed Closed
Make up air intake for furnace inside test zone without damper Sealed No preparation
Exhaust and supply fans Off Off
Fan inlet grills with motorized damper Closed Closed
Fan inlet grills without motorized damper Sealed No preparation
Ventilators designed for continuous use Sealed Sealed
Supply and exhaust ventilator dampers Sealed Held closed
Clothes dryer Off Off
Clothes dryer vent No preparation No preparation
Ventilation to other zones Sealed Sealed
Windows and exterior doors Latched Latched
Window air conditioners Sealed No preparation
Openings leading to outside the test zone Closed Closed
Openings within the test zone Open Open
Floor drains and plumbing traps Filled Filled
may require running the gauges over their full scale several times until a
8.2.2 Determine Site Altitude—Determinethealtitudeofthe
reproduciblezerocanbedemonstrated.Thegaugesshouldreturntowithin
measurement site, Alt in meters or feet, above mean sea level
1 Pa (0.004 in. H O) of zero after a measurement.
within 100 m (3×10 ft).
8.4.3 Primary Pressure Station—The target primary station
8.3 Building Preparation:
for induced building pressure difference shall be P =50 Pa
8.3.1 Establish Test Zone Envelope—Define the test zone
(0.20 in. H O). A minimum of five replicate measurements of
envelope appropriate for the goals of the test. Open all doors,
pressure and airflow at the primary pressure station are
windows, and other openings that connect portions of the
required. For the single-point method, only primary-station
building outside the test zone envelope with the outdoors.
pressuresarerequired.If50Paisnotachieved,usethehighest
NOTE 6—For example, if the first floor is to be the lower boundary of
sustainable pressure obtained.
thetestzoneenvelope,openbasementdoorsandwindows.Ifthefloorand
8.4.4 Secondary Pressure Station (two-point method)—
the basement are part of the test zone envelope, close those doors and
When using the two-point method, the secondary target pres-
windows.
sure station shall be P =12.5 Pa (0.05 in. H O). A minimum
2 2
8.3.2 Establish Test Zone—Allinteriorbuildingdoorsinthe
of five replicate measurements of pressure and airflow at the
test zone shall be open to create a uniform inside pressure. If
secondarypressurestationarerequired.Inallcases P shallbe
door-sized openings are not present within the test zone,
less than or equal to one third of P (P ≥ 3 P ).
1 1 2
performmeasurementstoconfirmthatthesingle-zonecriterion
8.4.5 Determining the Zero-Flow Pressure Difference—
referred to in 3.2.11 has been met.
Before and after each measurement at a pressure station, seal
8.3.3 Building Components—To follow the recommended
the fan opening in the blower door. Measure and record the
preparation of a residential building, choose the column in
inside-outside pressure differential at zero airflow in Pa (in.
Table 1 appropriate for the purpose of the test. Adjust all
H O).
building components in accordance with the appropriate entry
8.4.6 Pressure and Flow Measurements—For each replicate
in Table 1.
measurement, measure and record the airflow rate in cubic
metres per second (cubic feet per minute). Record the mea-
8.4 Blower Door Measurements:
8.4.1 Installation—Install the blower door in an entry with sured value for pressure each time in Pa (in. H O). Pressure
and flow measurements must occur within 20 s of each other.
minimal obstructions of airflow to and from the rest of the
building. Orient the blower door appropriately for depressur- 8.4.7 Pressurization and Depressurization—Whenperform-
ing both pressurization and depressurization measurements,
ization or pressurization as required.
8.4.2 Zero the Pressure Sensor—Connect the inside-outside record the pressurization and depressurization data separately
and perform separate calculations.
pressure sensor ports together and zero the pressure difference
sensor. Reconnect the inside-outside pressure sensor to mea-
9. Data Analysis and Calculations
sure the pressure difference across the envelope.
9.1 Station Pressure Calculation:
NOTE 7—Some blower doors may perform this or an equivalent step
9.1.1 Test Station Pressure—Calculate the station pressure
automatically. Follow the manufacturer’s instructions accordingly. When
mechanicalpressuregaugesareused,obtainingareproduciblegaugezero for each replicate measurement, using Eq 1:
E1827−22
P 1P ρ
zero1 zero2 out
P 5 P 2 (1) Q 5 Q (7)
S D S D
sta test env fan
2 ρ
in
where: where:
3 3
P = station pressure, Pa (in. H O), Q = the air leakage rate, m /s (ft /min).
sta 2 env
P = test pressure, Pa (in. H O),
test 2
9.3 Single-Point Method:
P = zero-airflow pressure before replicate measurement,
zero1
9.3.1 Air Leakage at 50 Pa (0.2 in. H O)—Calculate the
Pa (in. H O), and
¯
average of the values of Q , Q , and the standard deviation
P = zero-airflow pressure after replicate measurement,
env env
zero2
Pa (in. H O). of the values of Q . Estimate the standard air leakage rate at
env
50 Pa (0.2 in. H O) using Eq 8 for depressurization and Eq 9
9.1.2 Station Pressure Averages—For all replicates at a
for pressurization. For inch-pound units, use Eq A4.3 or Eq
¯
station pressure, calculate the average P , P , and standard
sta sta
A4.4.
deviation of the values of P .
sta
0.65 0.35 0.3
50Pa ρ µ
out out
9.2 Flow Calculation:
Q 5 Q (8)
S D S D S D
50 env1
P 1.2041 0.00001813
9.2.1 Calculate Air Densities—Use Eq 2 to calculate inside
0.65 0.35 0.3
airdensityorEq3tocalculateoutsideairdensit
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E1827 − 11 (Reapproved 2017) E1827 − 22
Standard Test Methods for
Determining Airtightness of Buildings Using an Orifice
Blower Door
This standard is issued under the fixed designation E1827; 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
1.1 These test methods describe two techniques for measuring air leakage rates through a building envelope in buildings that may
be configured to a single zone. Both techniques use an orifice blower door to induce pressure differences across the building
envelope and to measure those pressure differences and the resulting airflows. The measurements of pressure differences and
airflows are used to determine airtightness and other leakage characteristics of the envelope.
1.2 These test methods allow testing under depressurization and pressurization.
1.3 These test methods are applicable to small indoor-outdoor temperature differentials and low wind pressure conditions; the
uncertainty in the measured results increases with increasing wind speeds and temperature differentials.
1.4 These test methods do not measure air change rate under normal conditions of weather and building operation. To measure
air change rate directly, use Test Method E741.
1.5 The text of these test methods reference notes and footnotes that provide explanatory material. These notes and footnotes,
excluding those in tables and figures, shall not be considered as requirements of the standard.
1.6 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for
information only and are not considered standard.
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use. For specific hazard statements see Section 7.
1.8 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.
2. Referenced Documents
2.1 ASTM Standards:
These test methods are under the jurisdiction of ASTM Committee E06 on Performance of Buildings and are the direct responsibility of Subcommittee E06.41 on Air
Leakage and Ventilation Performance.
Current edition approved Sept. 1, 2017Oct. 1, 2022. Published September 2017October 2022. Originally approved in 1996. Last previous edition approved in 20112017
as E1827 – 11.E1827 – 11 (2017). DOI: 10.1520/E1827-11R17.10.1520/E1827-22.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’sstandard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E1827 − 22
E456 Terminology Relating to Quality and Statistics
E631 Terminology of Building Constructions
E741 Test Method for Determining Air Change in a Single Zone by Means of a Tracer Gas Dilution
E779 Test Method for Determining Air Leakage Rate by Fan Pressurization
E1186 Practices for Air Leakage Site Detection in Building Envelopes and Air Barrier Systems
E1258 Test Method for Airflow Calibration of Fan Pressurization Devices
E3158 Test Method for Measuring the Air Leakage Rate of a Large or Multizone Building
2.2 ISO International Standard:
ISO 9972 Thermal Insulation—Determination of Building Airtightness—Fan Pressurization Method
2.3 Other Standard:
ANSI/ASME PTC 19.1–1985 Part 1: Measurement Uncertainty, Instruments, and Apparatus
3. Terminology
3.1 Definitions:
3.1.1 For definitions of general terms related to building construction used in this test methods, refer to Terminology E631 and
for general terms related to accuracy, bias, precision, and uncertainty refer to Terminology E456.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 ACH , n—the ratio of the air leakage rate at 50 Pa (0.2 in. H O), corrected for a standard air density, to the volume of the
50 2
test zone (1/h).
3 3
3.2.2 air leakage rate, Q , n—the total volume of air passing through the test zone envelope per unit of time (m /s, ft /min).
env
3.2.3 airtightness, n—the degree to which a test zone envelope resists the flow of air.
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
E1827 − 22
NOTE 1—ACH , air leakage rate, and effective leakage area are examples of measures of building airtightness.
3.2.4 blower door, n—a fan pressurization device incorporating a controllable fan and instruments for airflow measurement and
building pressure difference measurement that mounts securely in a door or other opening.
3.2.5 building pressure difference, P, n—the pressure difference across the test zone envelope (Pa, in. H O).
3 3
3.2.6 fan airflow rate, Q , n—the volume of airflow through the blower door per unit of time (m /s, ft /min).
fan
3.2.7 nominal airflow rate, Q , n—the flow rate indicated by the blower door using the manufacturer’s calibration coefficients
nom
3 3
(m /s, ft /min).
3.2.8 orifice blower door, n—a blower door in which airflow rate is determined by means of the pressure drop across an orifice
or nozzle.
3.2.9 precision index of the average, n—the sample standard deviation divided by the square root of the number of samples.
3.2.10 pressure station, n—a specified induced change in the building pressure difference from the initial zero-flow building
pressure difference (Pa, in. H O).
3.2.11 single zone, n—a space in which the pressure differences between any two places, as indicated on a manometer, differ by
no more than 2.5 Pa (0.01 in. H O) during fan pressurization at a building pressure difference of 50 Pa (0.2 in. H O) and by no
2 2
more than 5 % of the highest building pressure difference achieved.
NOTE 2—A multiroom space that is interconnected within itself with door-sized openings through any partitions or floors is likely to satisfy this criterion
3 3 3
if the fan airflow rate is less than 3 m /s (6 × 10 ft /min) and the test zone envelope is not extremely leaky.
3.2.12 test zone, n—a building or a portion of a building that is configured as a single zone for the purpose of this standard.
NOTE 3—For detached dwellings, the test zone envelope normally comprises the thermal envelope.
3.2.13 test zone envelope, n—the barrier or series of barriers between a test zone and the outdoors.
NOTE 4—The user establishes the test zone envelope at such places as basements or neighboring rooms by choosing the level of resistance to airflow
between the test zone and outdoors with such measures as opening or closing windows and doors to, from, and within the adjacent spaces.
3.2.14 zero-flow building pressure difference, n—the natural building pressure difference measured when there is no flow through
the blower door.
3.3 Symbols—The following is a summary of the principal symbols used in these test methods:
Alt = altitude at site, m (ft),
3 n 3 n 4
C = flow coefficient at standard conditions, m /s (Pa ) ft /min (in. H O ),
2 2
L = effective leakage area at standard conditions, m (in. ),
n = envelope flow exponent (dimensionless),
P = building pressure difference (see 3.2.5),
P = average pressure, P¯ , at the primary pressure station, Pa (in. H O),
1 sta 2
P = average pressure, P¯ , at the secondary pressure station, Pa (in. H O),
2 sta 2
P = the reference pressure differential across the building envelope, Pa (in. H O),
ref 2
P = station pressure, Pa (in. H O),
sta 2
P = test pressure, Pa (in. H O),
test 2
P = zero-airflow pressure before test, Pa (in. H O),
zero1 2
Historically, a variety of other units have been used.
E1827 − 22
P = zero-airflow pressure after test, Pa (in. H O),
zero2 2
3 3
Q = the air leakage rate, m /s (ft /min),
env
3 3
Q = average air leakage rate, Q¯ , at the primary pressure station, m /s (ft /min),
env1 env
3 3
Q = average air leakage rate, Q¯ , at the secondary pressure station, m /s (ft /min),
env2 env
Q = fan airflow rate (see 3.2.6),
fan
Q = nominal airflow rate (see 3.2.7),
nom
T = temperature, °C (°F),
t = value from a two-tailed student t table for the 95 % confidence level,
δn = measurement uncertainty of the envelope flow exponent (dimensionless),
3 3
V = volume of the test zone, m (ft ),
zone
3 3
δQ = measurement uncertainty of the average air leakage rate, m /s (ft /min),
env
3 3
δQ = the measurement uncertainty of Q , m /s (ft /min),
50 50
3 3
δQ = estimated bias of the flow rate, m /s (ft /min),
bias
3 3
δQ = estimated bias of the flow rate at the primary pressure station, m /s (ft /min),
bias1
3 3
δQ = estimated bias of the flow rate at the secondary pressure station, m /s (ft /min),
bias2
3 3
δQ = precision index of the average measured flow rate, m /s (ft /min),
precision
3 3
δQ = precision index of the average measured flow rate at the primary pressure station, m /s (ft /min),
prec1
3 3
δQ = precision index of the average measured flow rate at the secondary pressure station, m /s (ft /min),
prec2
δP = measurement uncertainty of the average measured pressure differential across the building envelope, Pa (in. H O),
δP = estimated bias of the pressure differential across the building envelope, Pa (in. H O),
bias 2
δP = estimated bias of the pressure differential across the building envelope at the primary pressure station, Pa (in. H O),
bias1 2
δP = estimated bias of the pressure differential across the building envelope at the secondary pressure station, Pa (in.
bias2
H O),
δP = precision index of the average measured pressure differential across the building envelope, Pa (in. H O),
precision 2
δP = precision index of the average measured pressure differential across the building envelope at the primary pressure
prec1
station, Pa (in. H O),
δP = precision index of the average measured pressure differential across the building envelope at the secondary pressure
prec2
station, Pa (in. H O),
3 3
δV = measurement uncertainty of the zone volume, m (ft ),
zone
μ = dynamic viscosity, kg/m·s (lbm/ft·hr),
3 3
ρ = air density, kg/m (lbm/ft ), and
3 3
ρ = air density at which the calibration values are valid, kg/m (lbm/ft ).
cal
4. Summary of Test Methods
4.1 Pressure versus Flow—These test methods consist of mechanical depressurization or pressurization of a building zone during
which measurements of fan airflow rates are made at one or more pressure stations. The air leakage characteristics of a building
envelope are evaluated from the relationship between the building pressure differences and the resulting airflow rates. Two
alternative measurement and analysis procedures are specified in this standard, the single-point method and the two-point method.
4.1.1 Single-Point Method—This method provides air leakage estimates by making multiple flow measurements near P = 50 Pa
(0.2 in. H O) and assuming a building flow exponent of n = 0.65.
4.1.2 Two-Point Method—This method provides air leakage estimates by making multiple flow measurements near P = 50 Pa (0.2
in. H O) and near P = 12.5 Pa (0.05 in. H O) that permit estimates of the building flow coefficient and flow exponent.
2 2 2
5. Significance and Use
5.1 Airtightness—Building airtightness is one factor that affects building air change rates under normal conditions of weather and
building operation. These air change rates account for a significant portion of the space-conditioning load and affect occupant
comfort, indoor air quality, and building durability. These test methods produce results that characterize the airtightness of the
building envelope. These results can be used to compare the relative airtightness of similar buildings, determine airtightness
improvements from retrofit measures applied to an existing building, and predict air leakage. Use of this standard in conjunction
with Practices E1186 permits the identification of leakage sources and rates of leakage from different components of the same
building envelope. These test methods evolved from Test Method E779 to apply to orifice blower doors.
5.1.1 Applicability to Natural Conditions—Pressures across building envelopes under normal conditions of weather and building
operation vary substantially among various locations on the envelope and are generally much lower than the pressures during the
test. Therefore, airtightness measurements using these test methods cannot be interpreted as direct measurements of natural
infiltration or air change rates that would occur under natural conditions. However, airtightness measurements can be used to
E1827 − 22
provide air leakage parameters for models of natural infiltration. Such models can estimate average annual ventilation rates and
the associated energy costs. Test Method E741 measure natural air exchange rates using tracer gas dilution techniques.
5.1.2 Relation to Test Method E779—These test methods are specific adaptations of Test Method E779 to orifice blower doors.
For nonorifice blower doors or for buildings too large to use blower doors, use Test Method E779.
5.1.3 Relation to Test Method E3158—These test methods are applicable for buildings that are configured as a single zone. For
testing of multi-zone buildings, use Test Method E3158.
5.2 Single-Point Method—Use this method to provide air leakage estimates for assessing improvements in airtightness.
5.3 Two-Point Method—Use this method to provide air leakage parameters for use as inputs to natural ventilation models. The
two-point method uses more complex data analysis techniques and requires more accurate measurements (Tables X1.1 and X1.2)
than the single-point method. It can be used to estimate the building leakage characteristics at building pressure differences as low
as 4 Pa (0.016 in. H O). A variety of reference pressures for building envelope leaks has been used or suggested for characterizing
building airtightness. These pressures include 4 Pa (0.016 in. H O), 10 Pa (0.04 in. H O), 30 Pa (0.12 in. H O), and 50 Pa (0.2
2 2 2
in. H O). The ASHRAE Handbook of Fundamentals uses 4 Pa.
5.4 Depressurization versus Pressurization—Depending on the goals of the test method, the user may choose depressurization or
pressurization or both. This standard permits both depressurization and pressurization measurements to compensate for asymmetric
flow in the two directions. Depressurization is appropriate for testing the building envelope tightness to include the tightness of
such items as backdraft dampers that inhibit infiltration but open during a pressurization test. Combining the results of
depressurization and pressurization measurements can minimize wind and stack-pressure effects on calculating airtightness but
may overestimate air leakage due to backdraft dampers that open only under pressurization.
5.5 Effects of Wind and Temperature Differences—Calm winds and moderate temperatures during the test improve precision and
bias. Pressure gradients over the envelope caused by inside-outside temperature differences and wind cause bias in the
measurement by changing the building pressure differences over the test envelope from what would occur in the absence of these
factors. Wind also causes pressure fluctuations that affect measurement precision and cause the data to be autocorrelated.
6. Apparatus
6.1 Blower Door—An orifice blower door (see Fig. 1).
6.2 Measurement Precision and Bias—Appendix X1 lists recommended values for the precision and bias of the measurements of
airflow, pressure difference, wind speed, and temperature to obtain the precision and bias for test results described in 11.2 for the
single-point method and 11.3 for the two-point method.
FIG. 1 Blower Door Assembly
E1827 − 22
6.2.1 Fan with Controllable Flow—The fan shall have sufficient capacity to generate at least a 40 Pa (0.20 in. H O) building
pressure difference in the zone tested and be controllable over a calibrated range sufficient to generate the building pressure
differences required by this standard.
3 3 3 3
NOTE 5—For testing most single family houses, a range of airflows from 0.10.1 m /s to 3 m /s (200(200 ft /min to 6000 ft /min) is usually adequate.
6.2.2 Airflow Measurement—The procedure for calibrating the airflow measurement device shall be provided with the instrument
together with estimates of the precision and bias of the instrument. The air density (ρ ) for which any calibration equations or
cal
tables were calculated shall be reported. If the instrument automatically compensates for changes in air density, the instructions
shall note this fact.
6.2.3 Pressure Measurement—The procedure for calibrating the pressure measurement device shall be provided with the
instrument together with estimates of the precision and bias of the instrument.
6.3 Wind Speed Measurement (two-point method only)—A device to measure the site wind speed.
6.4 Air Temperature Measurement—A thermometer or electronic sensor with readout.
6.5 Barometer (optional)—A device to measure the site barometric pressure.
6.6 Data Acquisition (optional)—Automated data acquisition equipment to record (in machine readable form) data on airflow and
building pressure differences within 10 s of each other and (optionally) temperature, wind speed, and barometric pressure.
6.7 Pressure and Flow Measurement System (two-point method only)—The flow and pressure measurement system shall measure
flow and pressure differentials within 20 s of each other.
6.8 Wind Pressure Averaging System (optional)—A system to reduce the effect of pressure variations from static probes outside
the building envelope and of pressure fluctuations over time. It shall have a manifold that accepts multiple tubes of equal lengths
sufficient to reach representative surfaces of the building.
7. Hazards
7.1 Eye Protection—Glass should not break at the building pressure differences normally applied to the test structure. However,
for added safety, adequate precautions such as the use of eye protection should be taken to protect the personnel.
7.2 Safety Clothing—Use safety equipment required for general field work, including safety shoes and hard hats.
7.3 Equipment Guards—The air-moving equipment shall have a proper guard or cage to house the fan or blower and to prevent
accidental access to any moving parts of the equipment.
7.4 Noise Protection—Make hearing protection available for personnel who must be close to the noise that may be generated by
the fan.
7.5 Debris and Fumes—The blower or fan forces a large volume of air into or out of a building while operating. Exercise care
not to damage plants, pets, occupants, or internal furnishings due to influx of cold or warm air. Exercise similar cautions against
sucking debris or exhaust gases from fireplaces and flues into the interior of the building. Active combustion devices require a
properly trained technician to shut them off or to determine the safety of conducting the test.
8. Procedure
8.1 Establish Test Objectives—Determine the configuration of the building envelope to be tested. The most common objectives
are to evaluate the effect of construction quality on leaks in the building envelope (hereafter called closed) or to assess the
envelope’s impact on natural air change rates (hereafter called occupied). Choose the envelope condition appropriate to the
objective.
E1827 − 22
8.1.1 Residential Construction—Use Table 1 to determine the recommended test envelope conditions for residential construction.
8.1.1.1 Closed—Close all operable openings and seal other intentional openings to evaluate envelope airtightness without
including intentional openings.
8.1.1.2 Occupied (default)—Leave all operable openings in the conditions typical of occupancy to assess the envelope’s effect on
natural air change rates. This shall be the default option if no compelling reason exists to choose 8.1.1.1.
8.2 Ancillary Measurements:
8.2.1 Environmental Measurements—Measure and record the wind speed 2 m (6 ft) above the ground and 10 m (30 ft) upwind
from the building, when practical, outside temperature, and inside temperature at the beginning of each fan pressurization test.
Circle or otherwise emphasize the readings if wind speed is greater than 2 m/s (4 mph) or outside temperature is outside the bounds
of 55 °C to 35 °C (41(41 °F to 95 °F).
8.2.2 Determine Site Altitude—Determine the altitude of the measurement site, Alt in mmeters or ft,feet, above mean sea level
within 100 m (3 × 10 ft).
8.3 Building Preparation:
8.3.1 Establish Test Zone Envelope—Define the test zone envelope appropriate for the goals of the test. Open all doors, windows,
and other openings that connect portions of the building outside the test zone envelope with the outdoors.
NOTE 6—For example, if the first floor is to be the lower boundary of the test zone envelope, open basement doors and windows. If the floor and the
basement are part of the test zone envelope, close those doors and windows.
8.3.2 Establish Test Zone—All interior building doors in the test zone shall be open to create a uniform inside pressure. If
door-sized openings are not present within the test zone, perform measurements to confirm that the single-zone criterion referred
to in 3.2.11 has been met.
8.3.3 Building Components—To follow the recommended preparation of a residential building, choose the column in Table 1
appropriate for the purpose of the test. Adjust all building components in accordance with the appropriate entry in Table 1.
TABLE 1 Recommended Test Envelope Conditions
Envelope Conditions
Building Component
Occupied (Default) Closed
Vented combustion appliance Off Off
Pilot light As found As found
Flue to nonwood combustion appliance Sealed No preparation
Flues for fireplaces and wood stoves with dampers Closed Closed
Flues for fireplaces and wood stoves without dampers Ashes removed Ashes removed
Fireplace and wood stove doors and air inlet dampers Closed Closed
Fireplace without firebox doors No preparation No preparation
Furnace room door for furnace outside test zone Closed Closed
Combustion air intake damper for wood stove or fireplace Closed Closed
Make up air intake damper for furnace inside test zone Sealed Closed
Make up air intake for furnace inside test zone without damper Sealed No preparation
Exhaust and supply fans Off Off
Fan inlet grills with motorized damper Closed Closed
Fan inlet grills without motorized damper Sealed No preparation
Ventilators designed for continuous use Sealed Sealed
Supply and exhaust ventilator dampers Sealed Held closed
Clothes dryer Off Off
Clothes dryer vent No preparation No preparation
Ventilation to other zones Sealed Sealed
Windows and exterior doors Latched Latched
Window air conditioners Sealed No preparation
Openings leading to outside the test zone Closed Closed
Openings within the test zone Open Open
Floor drains and plumbing traps Filled Filled
E1827 − 22
8.4 Blower Door Measurements:
8.4.1 Installation—Install the blower door in an entry with minimal obstructions of airflow to and from the rest of the building.
Orient the blower door appropriately for depressurization or pressurization as required.
8.4.2 Zero the Pressure Sensor—Connect the inside-outside pressure sensor ports together and zero the pressure difference sensor.
Reconnect the inside-outside pressure sensor to measure the pressure difference across the envelope.
NOTE 7—Some blower doors may perform this or an equivalent step automatically. Follow the manufacturer’smanufacturer’s instructions accordingly.
When mechanical pressure gauges are used, obtaining a reproducible gauge zero may require running the gauges over their full scale several times until
a reproducible zero can be demonstrated. The gauges should return to within 1 Pa (0.004 in. H O) of zero after a measurement.
8.4.3 Primary Pressure Station—The target primary station for induced building pressure difference shall be P = 50 Pa (0.20 in.
H O). A minimum of five replicate measurements of pressure and airflow at the primary pressure station are required. For the
single-point method, only primary-station pressures are required. If 50 Pa is not achieved, use the highest sustainable pressure
obtained.
8.4.4 Secondary Pressure Station (two-point method)—When using the two-point method, the secondary target pressure station
shall be P = 12.5 Pa (0.05 in. H O). A minimum of five replicate measurements of pressure and airflow at the secondary pressure
2 2
station are required. In all cases P shall be less than or equal to one third of P (P ≥ 3 P ).
2 1 1 2
8.4.5 Determining the Zero-Flow Pressure Difference—Before and after each measurement at a pressure station, seal the fan
opening in the blower door. Measure and record the inside-outside pressure differential at zero airflow in Pa (in. H O).
8.4.6 Pressure and Flow Measurements—For each replicate measurement, measure and record the airflow rate in cubic metres per
second (cubic feet per minute). Record the measured value for pressure each time in Pa (in. H O). Pressure and flow measurements
must occur within 20 s of each other.
8.4.7 Pressurization and Depressurization—When performing both pressurization and depressurization measurements, record the
pressurization and depressurization data separately and perform separate calculations.
9. Data Analysis and Calculations
9.1 Station Pressure Calculation:
9.1.1 Test Station Pressure—Calculate the station pressure for each replicate measurement, using Eq 1:
P 1P
zero1 zero2
P 5 P 2 (1)
S D
sta test
where:
P = station pressure, Pa (in. H O),
sta 2
P = test pressure, Pa (in. H O),
test 2
P = zero-airflow pressure before replicate measurement, Pa (in. H O), and
zero1 2
P = zero-airflow pressure after replicate measurement, Pa (in. H O).
zero2 2
9.1.2 Station Pressure Averages—For all replicates at a station pressure, calculate the average P ,P¯ , and standard deviation
sta sta
of the values of P .
sta
9.2 Flow Calculation:
9.2.1 Calculate Air Densities—Use Eq 2 to calculate inside air density or Eq 3 to calculate outside air density. Use Eq A4.1 and
A4.2 for inch-pound units.
5.2553
12 0.0065·Alt 293
ρ 5 1.2041 (2)
S D S D
in
293 T 1273
in
E1827 − 22
5.2553
12 0.0065·Alt 293
ρ 5 1.2041 (3)
S D S D
out
293 T 1273
out
where:
Alt = altitude at site, m,
ρ = air density, kg/m , and
T = temperature, °C.
3 3
NOTE 8—The standard conditions used in calculations in this standard are 20 °C (68 °F) for temperature, 1.2041 kg/m (0.07517 lbm/ft ) for air density,
and mean sea level for altitude.
9.2.2 Calculate Dynamic Viscosities—Calculate the dynamic viscosities for inside (μ = μ, when T = T ) and outside (μ = μ,
in in out
when T = T ) air at the site using Eq A5.1 or Eq A5.2.
out
9.2.3 Nominal Airflow Rate—Use the manufacturer’s calibration coefficie
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