BUILDING ENCLOSURE AIR TIGHTNESS TESTING

BUILDING ENCLOSURE AIR TIGHTNESS TESTINGCourse Number: BCLUNA018-01PProvider Number:404108121

Darek Brandt, PE – Chief Engineer, Building Science Solutions

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AIA CES DISCLAIMER

Credit(s) earned on completion of this course will be reported to AIA CES for AIA members. Certificates of Completion for both AIA members and non-AIA members are available upon request.

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.

THIS PRESENTATION IS PROTECTED BY US AND INTERNATIONAL COPYRIGHT LAWS. REPRODUCTION, DISTRIBUTION, DISPLAY AND USE OF THE PRESENTATION WITHOUT WRITTEN PERMISSION OF THE SPEAKER IS PROHIBITED.

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COPYRIGHT MATERIALS

© 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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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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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:

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https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwin0dGox_XXAhWFRCYKHR_GC6EQjRwIBw&url=https://www.backyardchickens.com/articles/chicken-coop-ventilation-go-out-there-and-cut-more-holes-in-your-coop.47774/&psig=AOvVaw0qLOVPjcxWQ7GAY07WvZCh&ust=1512655324707362

Impacts of Air Leakage

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IMPACTS OF AIR LEAKAGE

Consequences

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Indoor Environment

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Indoor Environment


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Durability• Many building components degrade more

quickly with presence of moisture

Performance Problems

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Performance Problems


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.


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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


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Air Barriers :


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


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Air Barriers : Continuous over the entire building envelope


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Air Barriers : Continuous over the entire building envelope


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Code Requirements & Testing

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INTERNATIONAL ENERGY CONSERVATION CODE (IECC)


(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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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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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


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Air Barriers :

ASTM E2357 “Standard Test Method for Air Leakage of Air Barrier Assemblies”

Assembly Based and Quantitative Performance


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Air Barriers :ASTM D4541 (Modified) “Standard Test Method for Pull-Off Strength of Coatings Using Portable Adhesion Tester”


ASTM D4541 ADHESION TESTING

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Air Barriers :

ASTM E1186 “Air Leakage Site Detection in Building Envelopes and Air Barrier Systems”


Assembly Based and Qualitative Performance

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Air Barriers :

ASTM E1186 “Air Leakage Site Detection in Building Envelopes and Air Barrier Systems”


Assembly Based and Qualitative Performance



ASTM E1186 (4.2.7) “BUBBLE GUN”

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Fenestration : Windows, Doors, Skylights and Curtain Walls


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Fenestration :


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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”


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



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”



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”



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Whole Buildings:


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ASTM E1827 “ Standard Test Method for Determining Airtightness of Buildings Using an Orifice Blower Door”



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.


Building :


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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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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”



Building :

Multipoint Regression Method

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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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HVAC Excluded vs. Included

HVAC Excluded

Building Enclosure Area: 119,825 ft2

Performance: 0.137 cfm/ft2

HVAC Included



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


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



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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.


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

Documents

BUILDING ENCLOSURE AIR TIGHTNESS TESTING