BUILDING ENCLOSURE AIR TIGHTNESS TESTINGCourse Number: BCLUNA018-01PProvider Number:404108121
Darek Brandt, PE – Chief Engineer, Building Science Solutions
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This course is registered with AIA CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product._______________________________________
Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.
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© Intertek 2018
Building Enclosure Air Tightness Testing
Course DescriptionBuilding air tightness testing has been used for many years to identify and quantify the air leakagethrough building envelopes of buildings. These testing techniques can be used for various purposes.Construction quality assurance can be performed using various test methods. Air leakage characteristicsof a building can be used as a diagnostic tool when an older building experiences problems that may berelated to air leakage. Energy codes have recognized the importance of envelope air leakage resistanceand have become mandatory code requirements for the building envelope (ASHRAE 90.1 2010+, IECC2012+, others). However, simple inclusion of control layers in the design documents does not guaranteeperformance or durability under field application conditions. Material, assembly and building airtightness impacts code compliance, building performance, and the performance of associatedmechanical systems in the building.
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Building Enclosure Air Tightness Testing
Learning Objectives1. What is an air barrier?
2. What is building enclosure air tightness and why is it important?
3. What air tightness requirements exist and how are buildings meeting them?
4. What are the test methods?
5. How well do specific systems perform?
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Building Enclosure Air Tightness Testing
Outline
1. Air Flow & Air Leakage
2. Impacts
3. Types of Air Barriers
4. Testing
5. Case Studies
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Air Flow & Air Leakage Through Buildings
WHAT IS THE BUILDING ENCLOSURE/ENVELOPE?
The building envelope is the physical separator between the conditioned and unconditioned environment of a building. The building envelope provides
resistance to air, water, heat, light and noise. The building envelope Provides weather, air, and thermal barriers. Components include 1) floors, 2) roofs, 3)
walls, 4) windows/curtainwalls, 5) doors.
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BUILDING ENVELOPE AIR LEAKAGE
Building airtightness can be defined as the resistance to inward or outward air flow through unintentional leakage points or areas of the building envelope.
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AIR FLOW
For air flow to occur, there must be both: A pressure difference between two
points
A continuous flow path connecting the points
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AIR FLOW
Wind
Stack Effect
Mechanical Ventilation Systems
Forces:
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AIR FLOW
Orifice flow
Permeation/Diffusion
Channel flow
Types of Air Flow:
Impacts of Air Leakage
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IMPACTS OF AIR LEAKAGE
Consequences
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IMPACTS OF AIR LEAKAGE
Indoor Environment
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Indoor Environment
IMPACTS OF AIR LEAKAGE
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IMPACTS OF AIR LEAKAGE
Durability• Many building components degrade more
quickly with presence of moisture
Performance Problems
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Performance Problems
IMPACTS OF AIR LEAKAGE
Indoor Environment• Increased airtightness must be combined with an
appropriate ventilation system which minimizes pollutants and provide fresh air.
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Performance Problems Energy Efficiency• According to the United States Department of Energy, some
40 percent of energy of heating and cooling a building is lost by uncontrolled air leakage through the building envelope.
IMPACTS OF AIR LEAKAGE
AIR LEAKAGE
Energy Efficiency
Credit: Journal of Building Enclosure Design Summer 2011 “Improvement of Air Tightness in U.S. Army Buildings” pgs. 11-13
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Types of Air Barriers
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Air Barriers: Air Barriers are systems of materials designed and
constructed to control airflow between a conditioned space and an unconditioned space.
PRODUCT AND SYSTEM PERFORMANCE
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Air Barriers :• Membranes
• Sheathings
• Sealants
• Foams
PRODUCT AND SYSTEM PERFORMANCE
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PRODUCT AND SYSTEM PERFORMANCE
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Air Barriers :
PRODUCT AND SYSTEM PERFORMANCE
Materials with air permeability ≤0.004 cfm/ft2
Compliant Materials
• Plywood ≥ 3/8 in. thick
• Oriented Strand Board ≥ 3/8 in. thick
• Extruded Insulation Board ≥ 1/2 in. thick
• Foil-back Insulation Board ≥ 1/2 in. thick
• Closed-cell spray foam (min. density of 1.5 pcf and thickness ≥ 1-1/2 in.)
• Open-cell spray foam with density 0.4-1.5 pcf and thickness ≥ 4-1/2 in.
• Exterior or interior gypsum board ≥ 1/2 in.
• Cement board ≥ 1/2 in.
• Built-up roofing membrane
• Mod-bit roofing membrane
• Fully-adhered single-ply roofing membrane
• Portland cement/sand parge or gypsum plaster ≥ 3/8 in. thick
• Cast-in-place or precast concrete
• Fully grouted concrete block masonry
• Sheet steel or aluminum
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Air Barriers : Able to withstand movement and air pressure
differences
PRODUCT AND SYSTEM PERFORMANCE
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Air Barriers : Continuous over the entire building envelope
PRODUCT AND SYSTEM PERFORMANCE
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Air Barriers : Continuous over the entire building envelope
PRODUCT AND SYSTEM PERFORMANCE
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PRODUCT AND SYSTEM PERFORMANCE
Code Requirements & Testing
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INTERNATIONAL ENERGY CONSERVATION CODE (IECC)
PRODUCT AND SYSTEM PERFORMANCE
(0.004 cfm/sq.ft at 1.57 psf)
(0.04 cfm/sq.ft at 1.57 psf)
(0.40cfm/sq.ft at 1.57 psf)
Air Barriers :
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PRODUCT AND SYSTEM PERFORMANCE
Air Barriers :
Code Requirements
AIR LEAKAGE IN CODE: IECC, ASHRAE 90.1 (2016)
Assembly
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Material Whole Building
< 0.004 cfm/ft2 75 Pa
Material Only
No detailing or transitions
No impact of weather or site conditions
< 0.04 cfm/ft2 75 Pa
Simulated Window
Detailing included
No Interface details
No impact of weather or site conditions
<0.40 cfm/ft2 75 Pa
Real Construction
Detailing Included
Transitions Included
OR OR
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PRODUCT AND SYSTEM PERFORMANCE
Material Based
Assembly Based
Building Based
Test Methods and Performance Standards are:
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Air Barriers :
ASTM E2178 “Standard Test Method for Air Permeance of Building Materials”
Material Based and Quantitative Performance
PRODUCT AND SYSTEM PERFORMANCE
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Air Barriers :
ASTM E2357 “Standard Test Method for Air Leakage of Air Barrier Assemblies”
Assembly Based and Quantitative Performance
PRODUCT AND SYSTEM PERFORMANCE
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Air Barriers :ASTM D4541 (Modified) “Standard Test Method for Pull-Off Strength of Coatings Using Portable Adhesion Tester”
PRODUCT AND SYSTEM PERFORMANCE
ASTM D4541 ADHESION TESTING
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Air Barriers :
ASTM E1186 “Air Leakage Site Detection in Building Envelopes and Air Barrier Systems”
PRODUCT AND SYSTEM PERFORMANCE
Assembly Based and Qualitative Performance
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Air Barriers :
ASTM E1186 “Air Leakage Site Detection in Building Envelopes and Air Barrier Systems”
PRODUCT AND SYSTEM PERFORMANCE
Assembly Based and Qualitative Performance
ASTM E1186 (4.2.7) “BUBBLE GUN”
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ASTM E1186 (4.2.7) “BUBBLE GUN”
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ASTM E1186 (4.2.7) “BUBBLE GUN”
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ASTM E1186 (4.2.7) “BUBBLE GUN”
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Fenestration : Windows, Doors, Skylights and Curtain Walls
PRODUCT AND SYSTEM PERFORMANCE
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Fenestration :
PRODUCT AND SYSTEM PERFORMANCE
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ASTM E283, Standard Test Method for Determining Rate of Air Leakage Through Exterior Windows, Curtain Walls, and Doors Under Specified Pressure Differences Across the Specimen”
PRODUCT AND SYSTEM PERFORMANCE
Assembly Based and Quantitative PerformanceFenestration :
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ASTM E783, Standard Test Method for Field Measurement of Air Leakage Through Installed Exterior Windows and Doors
PRODUCT AND SYSTEM PERFORMANCE
Assembly Based and Quantitative PerformanceFenestration :
Window Frame
ASTM E783 - This Test method addresses the issue of air leakage through the high pressure face of the test specimen only. Air leakage from the adjacent wall cavity through sill, head, and jambs of the window frame is considered extraneous air leakage.
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ASTM E2319 (MODIFIED FOR FIELD)“Standard Test Method for Determining Air Flow Through the Face and Sides of Exterior Windows, Curtain Walls, and Doors Under Specified Pressure Differences Across the Specimen”
PRODUCT AND SYSTEM PERFORMANCE
Assembly Based and Quantitative PerformanceFenestration :
Procedure1. Interior & exterior perimeter seal must
be installed
2. Tape or bag outside and tape inside (All Joints)
3. Record flow = tare (a)
4. Remove inside tape. Record flow = (b) tare + frame
5. (b - a) = frame (c)
6. Remove outside tape/bag. Record flow = (d) tare + frame + surface
7. (d - b) = (e) outside surface
8. (c + e) = Total Window
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Roof :
ASTM E1680 “Standard Test Method for Rate of Air Leakage through Exterior Metal Roof Panel System”
Assembly Based and Quantitative Performance
PRODUCT AND SYSTEM PERFORMANCE
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Whole Buildings:
PRODUCT AND SYSTEM PERFORMANCE
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ASTM E1827 “ Standard Test Method for Determining Airtightness of Buildings Using an Orifice Blower Door”
PRODUCT AND SYSTEM PERFORMANCE
Assembly Based and Quantitative Performance
Building :
• Single Point Method
• Multiple flow measurements near a single pressure
• Two-Point Method
• Multiple flow measurements near two pressures.
ASTM E779 “ Standard Test Method for Determining Air Leakage Rate of Building by Fan Pressurization”• Multi Point Regression Method
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USACE Air Leakage Test Protocol for Building Envelopes• Test procedure/building preparation is more clearly defined than ASTM E779
• Requires positive and negative pressurization sets
• Defines acceptable induced pressure range
• Does not allow data extrapolation (10 data points and must measure at 75 Pa)
• Defines acceptable ranges for correlation coefficient squared, r2, and the pressure exponent, n
• Requires diagnostic procedures included in ASTM E1186 (Infrared and smoke tracers) to help determine air leakage sites.
PRODUCT AND SYSTEM PERFORMANCE
Building :
Assembly Based and Quantitative Performance
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PERFORMANCE STANDARDS
ABAA “Standard Method for Building Enclosure Airtightness Compliance Testing”
• Evolution of ASTM E779 and ASTM E1827 due to shortcomings of the original standards
• Includes multipoint regression, single point, and two point methods.
• Will become a new ASTM standard, phasing out ASTM E779.
Building :
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PERFORMANCE STANDARDS
Typical Allowable Building Leakage
• 0.4 cfm/sf @ 75 Pa (IBC, GSA)
• 0.25 cfm/sf @ 75 Pa (USACE)
• 0.10 cfm/sf @ 75 Pa (State of Utah)
• 0.6 ACH at 50 Pa (Passive House) or 0.05 cfm/sf at 50 Pa
Building :
ASTM E779 WHOLE BUILDING AIR LEAKAGE TEST
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ASTM E779 “ Standard Test Method for Determining Air Leakage Rate by Fan Pressurization”
PRODUCT AND SYSTEM PERFORMANCE
Assembly Based and Quantitative Performance
Building :
Multipoint Regression Method
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PRODUCT AND SYSTEM PERFORMANCE
ASTM E1186 (4.2.1) “INFRARED THERMOGRAPHY”
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ASTM E1186 (4.2.1) “INFRARED THERMOGRAPHY”
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ASTM E1186 (4.2.6) “SMOKE TRACER”
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ASTM E1186 (4.2.6) “SMOKE TRACER”
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PERFORMANCE STANDARDS
HVAC Excluded vs. Included
HVAC Excluded
Building Enclosure Area: 119,825 ft2
Performance: 0.137 cfm/ft2
HVAC Included
Building Enclosure Area: 119,825 ft2
Performance: 0.174 cfm/ft2
Over 4,000 cfm of air leakage through dampers
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Mechanically Fastened Air Barrier:
Building Description: Two-Story Police DepartmentBuilding Enclosure: Basis of Design
• Slab-on-Grade Air Control: Slab on Grade/Vapor Barrier Membrane
• Walls: Rain Screen Cladding, Fin Windows employed at punched wall openings. Air Control: Mechanically Fastened Membrane and Fenestration
• Roof Assembly: Vented Steep-Sloped Asphalt Shingle Roof Air Control: Second Floor Drywall Ceiling
Building Enclosure Area: 37,036 ft2
Performance: 0.724 cfm/ft2 *(extrapolated from 35 PA)
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Mechanically Fastened Air Barrier:
Building Description: Four-Story Apartment Building with Ground Floor Parking SpaceBuilding Enclosure: Basis of Design
• First Floor Slab/Slab-on-Grade Air Control: Concrete Slab
• Walls: Rain Screen Cladding, Aluminum Windows employed at punched wall openings. Air Control: Mechanically Fastened Membrane and Fenestration
• Roof Assembly: Vented Low-Sloped Built-up Roof supported by Wood Deck• Air Control: Fourth Floor Drywall Ceiling
Building Enclosure Area: 37,250 ft2
Performance: 0.541 cfm/ft2
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Spray Foam Air Barrier:
Building Description: Three-Stories; with Offices, Lecture Halls, Classrooms, AuditoriumBuilding Enclosure: Basis of Design
• Slab-on-Grade Air Control: Slab on Grade/Vapor Barrier Membrane
• Walls: Brick Cavity Wall, Aluminum Windows at punched wall openings, and portions of Curtain Wall. Air Control: Closed Cell Spray Foam in conjunction with Self-adhered Sheet and
Fluid Applied Air Barrier Membranes at transitions, wall openings, penetrations, control joints, substrate transitions, etc. and Fenestration
• Roof Assembly: Fully Adhered Single-Ply Membrane supported by Concrete Deck Air Control: Concrete Deck/Single Ply Membrane.
Building Enclosure Area: 216,300 ft2
Performance: 0.197 cfm/ft2 *
REVIEW
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ASTM E779
ASTM E1186
ASTM E1186
ASTM E1186 ASTM E1186
“Take Aways”
Air Barriers are essential to a high performance building enclosure
There are many different systems/methods
The performance verification of materials, assemblies and whole buildings helps to ensure quality control during the design and construction process
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QUESTIONS AND DISCUSSION
Darek Brandt, PE - Chief EngineerBuilding Science [email protected]
Phone: 407-304-5560
Darek Brandt, PE - Chief EngineerBuilding Science [email protected]
Phone: 407-304-5560
This concludes The American Institute of Architects Continuing Education Systems Course