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BlogsLeakage Test Protocol for Measuring Air Leakage in Buildings (USACE)U.S. Army Corps of Engineers Air Leakage Test Protocol for Measuring Air Leakage in Buildings
Scope of Inspection:
(USACE): Test the completed building and demonstrate that the air leakage rate of the building
envelope does not exceed 0.25 cfmlft2 at a pressure differential of 0.3" w.g. (75 Pa) in
accordance with ASTM's E 779 (2003) or E 1827-96 (2002). Accomplish tests using
both pressurization and depressurization. Divide the volume of air leakage in cfm @ 0.3"
w.g. (Lis @ 75 Pa) by the area of the pressure boundary of the building, including roof or
ceiling, walls and floor to produce the air leakage rate in cfm/ft2 @ 0.3" w.g. (L/s.m2 @
75 Pa). Do not test the building until verifying that the continuous air barrier is in place
and installed without failures in accordance with installation instructions so that repairs to
the continuous air barrier, if needed to comply with the required air leakage rate, can be
done in a timely manner.
Test the completed building using Infrared Thermography testing. Use infrared cameras
with a resolution of O. 1 deg C or better. Perform testing on the building envelope in
accordance with ISO 6781: 1983 and ASTM C 1060-90 (1997). Determine air leakage
pathways using ASTM E 1186-03 Standard Practices for Air Leakage Site Detection in
Building Envelopes and Air Barrier Systems, and perform corrective work as necessary
to achieve the whole building air leakage rate specified above.
Demonstrate performance of the continuous air barrier for the building envelope by the following tests:
a. Test the completed building and demonstrate that the air leakage rate of the building envelope does not
exceed 0.25CFM/sq ft at a pressure differential of 0.3 in. wag (75 Pa) in accordance with ASTM E- 779
(2003) or E- 1827-96 (2002). Accomplish tests using BOTH pressurization and depressurization. Divide the
average measured air leakage flow rate in both directions in CFM @ 0.3 in. wag (L/s @ 75 Pa) by the
surface area of the envelope enclosed by the continuous air barrier of the building, including roof or ceiling,
walls and floor to produce the air leakage rate in CFM/sq ft @ 0.3 in. wag (L/s.m2 @ 75 Pa).
For buildings where doorways of each apartment/office/room lead to the outdoors (i.e., where there is no direct interior connection between all the rooms), each apartment/office/room must be tested individually. Walls abutting adjacent apartments are to be treated as part of the envelope in spite of the fact that an argument can be made that leakage of the adjacent walls would be to another conditioned apartment and could therefore be ignored. To allow for efficient testing, common walls will be treated as part of the total envelope for the apartment and each apartment must pass the criteria. In multi-unit apartments, each style of apartment must be tested, including all corner rooms, and at least 20 percent of all other apartments must be tested.
An initial site assessment was made of the building layout and conditions affecting the ability to perform the required testing. It was noted during this assessment that several conditions existed which would hinder or prevent applying the testing protocol of USACE.
USACE: Do not test the building until verifying that the continuous air barrier is in place and installed without failures in accordance with installation instructions so that repairs to the continuous air barrier, if needed to comply with the required air leakage rate, can be done in a timely manner.
As on-site conditions present at the time of assessment could not be controlled or manipulated to facilitate air barrier testing to this protocol, an alternative test procedure was performed in an attempt to assess performance of the building envelope and to help the construction team identify additional areas of leakage that could be sealed on the current building or similar future buildings.
The testing procedure was based upon USACE guidelines as follows:
Optional: Set-up the door fan and run preliminary test
Occasionally, no additional testing will be required, as a preliminary test can help determine the following:
1. The quantity of additional door fans needed to achieve the desired test pressure.
2. A rough estimate as to whether the enclosure could pass, which may force the testing agency to spend more
time investigating enclosure problems, instead of using time to verify an obvious failing enclosure.
4.7 Locating Leakage Sites with Pressurization and Depressurization
If the building fails the test, it is important to determine the source of the air leakage. It is also beneficial for the
design-build team to understand the locations and details that are susceptible to leakage.
Test Results:
Room #1 (center third-floor, north exposure): blower door testing was conducted utilizing both pressurization and depressurization protocol.
The air barrier envelope area was approximated at 519 ft.².
Depressurization Testing: 595 CFM75/ft.²
Pressurization Testing: 772 CFM75/ft.²
Results Averaged: 683 CFM75/ft.²
Test results: 0.69 CFM75/ft.²
Room #2 (corner third-floor, southeast exposure): blower door testing was conducted utilizing both pressurization and depressurization protocol
The air barrier envelope area was approximated at 1127 ft.².
Depressurization Testing: 457 CFM75/ft.²
Pressurization Testing: 690 CFM75/ft.²
Results Averaged: 574 CFM75/ft.²
Test results: 0.51 CFM75/ft.²
(USACE) Neutral buoyancy smoke, theatrical smoke and infrared (IR) are effective means to find leakage sites .
Neutral buoyancy smoke testing was conducted during blower door testing which documented and later confirmed infrared thermal imaging scans indicating points of air bypass.
(USACE) When testing equipment depressurizes the enclosure, air leaks can be observed from the inside using infrared thermography and smoke generation. The manipulation of the HVAC system is required to perform an effective infrared thermography scan to achieve a temperature differential of at least 10 °F.
An Infrared Training Center (ITC) Level I Certified Infrared Thermographer is required by this protocol to perform
the infrared diagnostic evaluation. Otherwise, the agency must submit the qualifications of the infrared
thermographer, who must have at least 5 years experience in building science applications with infrared
thermography. Anomalies such as thermal bridges and emissivity reflections are commonly mistaken as air leakage.
The testing agency must employ thermographers with experience in building enclosures and building physics to
achieve accurate diagnoses and to make effective recommendations to the design-build contractor in the event of
failure and repair.
b. Test the completed building using Infrared Thermography testing. Use infrared cameras with a resolution of
0.1 °C or better. Perform testing on the building envelope in accordance with International Organization for
Standardization (ISO) 6781:1983 and ASTM C1060-90(1997). Determine air leakage pathways using
ASTM E 1186-03 Standard Practices for Air Leakage Site Detection in Building Envelopes and Air Barrier
Systems, and perform corrective work as necessary to achieve the whole building air leakage rate specified
in (a.) above.
Thermal Camera: Flir T 400; 320 x 240 resolution;Thermal Sensitivity (NETD) 0.05° C
Thermographer: ITC (infrared training Center) Level III Thermographer #1958
Infrared Thermography Scan Results:
*Add thermal pictures
Summary:
Future follow-up testing following this initial site assessment should consider the testing protocol in the U.S. Army Corps of Engineers Air Leakage Test Protocol for Measuring Air Leakage in Buildings. Particular attention to the following requirements for testing:
The ability to Seal or otherwise effectively isolate all “intentional” holes in the building enclosure. This includes air intake or exhaust louvers, make-up air intakes, pressure relief dampers or louvers, dryer and exhaust vent dampers and any other intentional hole that is not included in the air barrier design or construction. Intentional openings can be sealed by using an air-tight film or by motorized or manual dampers held in the closed position.
Ensure that all plumbing traps are filled with water.
The HVAC system must be shut down or disabled for the duration of the test. If the HVAC system activates during the test, additional air movement across the enclosure is introduced and is not measured by the agency, resulting in inaccurate data.
The manipulation of the HVAC system is required to perform an effective infrared thermography
scan to achieve a temperature differential of at least 10 °F.
In some cases, recirculating air handlers may also need to be turned off.
The contractor must provide a responsible HVAC technician with the authority to place the HVAC system in
the correct mode for the pressure test.
The testing agency must have unhindered access to mechanical rooms, air handlers, exhaust fans, and outdoor air and exhaust dampers.
The contractor shall ensure that no sub-contractors are working in the area of the fan pressurization test
equipment.
All components of the air barrier system have been installed and inspected, and have passed any
intermediate testing procedures as detailed in the construction drawings and specifications.
Submitted by DavidAndersen on Thu, 02/14/2013 - 13:09.
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