Building Envelope and Air Barrier Testing · PDF fileBuilding Envelope and Air Barrier...

WEBINAR SERIES | 20150 WEBINAR SERIES | 2015

Ed Simpson, CCP, CPMMTESTCOMM, LLC

BUILD. CONNECT. ACHIEVE.

Building Envelope and

Air Barrier Testing

WEBINAR SERIES | 20151

AIA Quality Assurance

• The Building Commissioning Association is a Registered Provider with The

American Institute of Architects Continuing Education Systems (AIA/CES). Credit(s) earned on completion of this program 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 program 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.


Course Description

• The Air Barrier is an integral part of the building envelope and,

according to the IECC and WSEC is an element that must be

tested for proper installation and performance. Identifying and

understanding how elements and assemblies that make up the

building envelope interact; the critical part that the air barrier

plays in the building envelope, along with understanding the

testing process and responsibilities of the various parties involved

in the design, construction and testing, will help deliver a quality

building for the Owner and make commissioning of the envelope

system much easier for the “whole building” commissioning

authority.


Learning Objectives

Participants will be able to:

• Identify primary elements and assemblies that make up the air

barrier and building envelope in new construction.

• Identify code requirements and standards that dictate air barrier

testing

• Identify air barrier design elements that enhance building

performance, provide occupant comfort and safety, and

provide energy savings for the Owner.

• Identify responsibilities of Architects, Engineers, Contractors, the

testing agency and Commissioning Authority for air barrier

testing.

• Identify proper testing techniques so witnessing and validating

the air barrier test can be properly accomplished


Building Enclosure and Air Barrier- Are They The Same?

Building enclosure-That “thing” between the inside and outside of the building that separates conditioned space from the outside environment…may include the Air Barrier and other elements, such as façade, vapor barrier, insulation, fenestration (windows and doors), etc., but often used synonymously.


Air Barrier Testing is not-

• Full Building Enclosure Commissioning• Vapor Barrier testing and commissioning• Thermal transferrance testing• Sound transferrance testing

Beware- codes and specifications often use Air Barrier testing and Building Envelope commissioning interchangeably- Know the difference between all of the activities.


Building Envelope- separates the inside from the outside and may include vapor and air barrier elements

Air Barrier separates conditioned and unconditioned spaces, either at the building envelope or within a building.

Examples: Warehouse building with offices and unheated storage space- air

barrier would normally include office space only.Hotel with unheated garage space underneath- Air barrier would

consist of hotel space onlyBank Branch with unheated attic space- Air barrier would consist of

the heated space on main floor only. Air Barriers can also separate conditioned spaces within a building.

Hospital with isolation rooms- difference in positive and negative pressures or different uses can require an air barrier

What’s the Dif?


UNCONDITIONED

CONDITIONED

UNCONDITIONED


So, What’s this “thing” called an Air Barrier?

Air barriers are a system of assemblies, products, components and details that, when properly installed, prevent or limit the leakage or transport of air and air infiltration into and out of the building envelope or conditioned spaces within a building.

An effective air barrier must:• Be fully bonded and fully adhered to the substrate to transfer positive

and negative wind or air pressure loads to the substrate• Provide continuous coverage across varying substrates to assure

uninterrupted air barrier protection• Feature integrated details across the entire conditioned space• Deliver waterproof performance to assure long term durability• Offer flexibility in design for varying wall configurations and climatic

conditions

Not to be confused with the vapor barrier, which may be an element of the building envelope assembly.


Air Barrier vs. Vapor Barrier- don’t get confused

Air Barrier- used to stop the movement of air in and out of the conditioned space (water vapor can also be transported by air)

Vapor Barrier- used to stop the movement of water vapor through the assembly. VB are installed on the warm side of the insulation in a building assembly. Vapor barrier position determined based on climatic conditions-in

warm climates it will be on the exterior; in cold climates- interior Same materials may be used for both vapor and air barriers In warm climates, may be the same component


Why do we test Air Barriers in Buildings?

Continuous air barriers increase energy efficiency, allow for

more precise control of building interior conditions and

extend building durability. Heating and cooling loss through air barriers result in poor mechanical

system operation and additional energy to condition the building. This adds

up to additional costs for the owner and can result in premature failure of

equipment

Uncontrolled air leakage can allow environmental allergens/ pollutants and

other airborne contaminants into the building.

In heating zones, leakage can cause condensation, ice dams, and failure of

building cladding systems.

In cooling zones, exterior, warm, moist air can cause condensation on inside

and promote mold growth. Properly applied air barriers can prevent the

infiltration of moisture laden air through the envelope.

Rain and other forms of precipitation can penetrate the building envelope. A

properly designed air barrier (exterior) can also provide the primary drainage

plane to shed the precipitation.


Aren’t buildings airtight enough already?

Simple answer- NO! (according to Department of Energy)

• In cooler climates, estimated that air leakage is responsible for

up to 43% of heating loads in buildings.

• According to a NEBB survey, in sample of 203 commercial

buildings, the average measured air leakage was 1.55 CFM per

SF of above grade surface when tested at 0.3” w.g pressure

difference.

• AB SF= H x W of envelope surface, including roof and floor area.

Example- H=16 W= 100 for all 4 sides, roof = 100x100, floor

100x100= 6400 SF wall surface+ 20000 SF Roof/floor =

26400 SF total x 1.55 CFM

• Leakage potential = 40,920 CFM air loss in building (the size of a

medium/ large sized air handling unit)

• That means that you would have to supply 40,900 CFM MORE

heating and cooling = $ on bottom line over life of the building


Codes, Regulations and Guidelines, Oh My!


Lot’sa folks tell us what to do• IECC define procedures in energy code

• USACE guidelines to be used for government facilities under their

purview

• NIBS Guideline 3-2006 - Exterior Enclosure Technical

Requirements for the Commissioning Process

• AABA- American Air Barrier Association- procedures and guides

• ASHRAE/IESNA 90.1 - Energy Standards for Buildings

• ASHRAE 189.1- Energy Standards for Buildings

• ASTM E779 - Standard Test Method for Determining Air Leakage

Rate by Fan Pressurization

• ASTM E1185- Standard Practices for Air Leakage Site Detection in

Building Envelopes and Air Barrier Systems

• Seattle Energy Code (Seattle area only)

• Local Building Code Official option

• Project Specifications in Division 1 and Division 7


Some requirements for ABT/ BETIECC

• Requirement has been in effect since 2006 code, originally for buildings 5

stories and above, now for all commercial and multi-family buildings.

• Target air leakage is 0.40 CFM/ft2 or less at dP of 0.3” w.g (75 pascals)

• Requires that testing be performed by fan pressurization,

depressurization or both

• Includes requirements for inspection of building envelope before testing

• Design review includes exterior details such as window, insulation,

building wrap, caulking, flashings, etc. by knowledgeable consultant.

LEED v4 Enhanced Commissioning

• Building Envelope testing can be used to get enhanced points along with

continuous building monitoring

Gov’t Agencies (USACE, VA, NAVFAC, GSA,etc.) require air barrier or BET.

State codes may require some form of AB verification

(CA,CT,DC,GA,IL,MD,MA,MN,MS,NY,OR,RI,WA all have codes that incorporate

Air barrier requirements )


Enough code stuff-What does it really say?

• All air barrier penetrations must be sealed, caulked, or gasketed

so air doesn’t leak

• Window air leakage must meet requirements in the code table

• Doors and openings sealed or weather-stripped to meet code,

with some exceptions

• Air intakes, exhaust openings, stairways and shaft vents must

have dampers

• Cargo doors (think loading docks, roll up doors) must have

weather seals

• All building entrances shall have vestibules- doors in and out must

have self closing devices and designed so interior and exterior

doors are not open at the same time

• Recessed lighting in the building envelope sealed to limit air

movement between inside and outside…sealed or gasketed

between housing and wall or ceiling.


What if it doesn’t pass?• Depends on the jurisdiction you are in – some jurisdictions have

mandatory provisions, some offer a get out of jail free card.

• WA State example: “Compliance shall be demonstrated by

performing a whole building test of the completed building and

documenting the results of the test. A final certificate of occupancy

shall not be issued for the building or portion thereof, until the building

official determines the building, or portion thereof, has been tested in

accordance with the WSEC.” Get out of jail free card- If the building

fails the first test, do practical remedial steps and retest. If the building

official says you did what you could, and it still doesn’t pass, he can

issue the COO.

• CA example: CA energy Code (Title 24) does not address pass/ fail

Cal Green Code- says testing has to be verified by third party

• Gov’t Agencies (USACE/VA, etc.): Spelled out in separate guides or in

construction specifications


Allowable AB Leakage Rates in USA

EXAMPLES:

• USACE/NAVFAC/VA 0.25 CFM/SF

• IgCC 0.25 CFM/SF

• IECC-2012/ 2015 0.40 CFM/SF

• ASHRAE 90.1-2013 0.40 CFM/SF

• GSA P100 0.40 CFM/SF

• ASHRAE 189.1- 2011 0.40 CFM/SF

• Remember, buildings are not static, they are “living” structures

and because of envelope expansion and contraction due to

weather conditions, the building breathes. The leakage

allowance accounts for this differential.


Air Barrier Construction


In general, there are two ways for air to penetrate a building-1) Through cracks or joints, or

other openings in the barrier/envelope

2) Through the construction materials (ex.- cinder block walls, filled, open cell styro-foam forms)

Ways Air Can Penetrate the Air Barrier and Building Envelope


Air is Sneaky- THINK- where can air go in or

out

• Joints around manufactured or site built fenestration and door

frames

• Junctions between walls and foundations, between walls at

building corners, between walls and structural floors or roofs, and

between walls and roof or roof panels.

• Openings at penetrations of utility services through envelope

• Building assemblies used as ducts or plenums

• Through semi-permeable materials (CMU, Open Cell Styrofoam)

• Joints, seams and penetrations of vapor retarders

• Recessed lighting fixtures


Typical Air Barrier Assemblies/Components-NW

• In WallsGyp Board Vapor BarrierInsulationCurtain WallsFenestrationFlashingsSealants/Coatings

• In RoofsMembranes/ Air or Vapor BarrierCurbsFlashingsSealants and Coatings

• In Floors Air or Vapor BarrierInsulation

Images courtesy of NEBB


CONSTRUCTION DETAILS MATTER


APPLICATION INSTRUCTIONS ARE IMPORTANT


EXAMPLES OF AIR BARRIER MATERIALS


TEAM MEMBER RESPONSIBILITIES, OR

WHO DOES WHAT TOGIT-ER-DONE!


It Starts With The Owner’s OPR and BOD

The Owner, through the OPR should specify what is to be included in the air barrier designation. This is especially important where the air barrier is not at the building enclosure (i.e. hospital isolation rooms, buildings with unconditioned spaces, etc.)

BOD should provide details on how the air barrier requirements are to be met, including proposed materials for sealing envelope, proposed methods for sealing joints, transitions, etc. between assemblies and elements of air barrier and method of testing to be used in the process.


Design Team Responsibilities

o Arch- Show, detail and specify the air barrier in the construction documents

o Arch- Build quality control in the front end so you aren’t fixing at the back end

ME- takes fresh air requirements into consideration when designing systems and sequences of operation (code required DOAS air handling units)

ME - include items like low leakage dampers, minimum penetrations thru the air barrier

EE -keeping air barrier penetrations to a minimum, specifying exterior luminaires that have sealing gaskets and may already be rated for leakage.


General Contractor

Since the air barrier testing can occur at any time during the construction schedule when it is determined the air barrier is complete, the GC has many hats to wear.

Advance planning- Construction document review, selection of trades, submittal review, required mock up’s, field testing, Air Barrier QA/QC, air barrier pre-test, troubleshooting, and final testing.

Coordinate subcontractor work involving the air barrier system

Other support requirements specified in Division 01 and 7 specifications.


Air Barrier Test Technician/ BE Consultant

Do a pre-test meeting and review all requirements for testing.

Provide all test equipment and technical expertise

Inspect preparations before testing Conduct test and infrared scan of building Assist in identifying and eliminating sources of

air leakage before, during, and after testing Re-test if necessary Prepare a report for the Owner and Building

Official


BECxA- What am I looking at?


Some other things to look for-

• Sealing around utility/ mechanical penetrations• Sealing around exterior recessed lighting• Roof membrane overlap of parapets and

flashings• Proper flashings at roof penetrations and curbs• Caulking and sealing fenestration and transitions• Weather stripping and sealing at doors• Compare details to actual construction- is it done

per plan details and manufacturer’s instructions?


Do we have issues?


Air Barrier Testing with Blower Door


Basic Air Barrier Testing Equipment


BASIC TEST PROCEDURE EXPLAINED Verify building is ready for testing Setup test equipment Pressurize building and record results Infrared Scan, if necessary, for evaluation De-pressurize building Infrared Scan, if necessary, for evaluation Verify calculations/ results of test If building fails, identify issues or areas that

need remediation Prepare report for Owner/ contractor Re-test, if necessary


Air exfiltration under 0.3” pressure


Air Infiltration under 0.3” negative pressure

Negative pressurization can detect issues that don’t show up under positive pressurization


1. Air Barrier Testing is important for energy conservation, indoor air quality and comfort for the occupants of a building.

2. Building envelope, air barrier and vapor barrier are used interchangeably, but are different animals

3. Air is sneaky… can get in and out in many ways4. Lots of ways to skin the cat- or building- to prevent energy losses through the BE/AB5. Codes/ standards address the issue of air barriers and building envelope testing6. No two projects are the same. Many people responsible for steps from OPR and

design through final testing and occupancy. Time spent on planning, coordination, communication and training can make things easier.

7. Testing agency has multiple methods to perform testing, but it takes COOPERATION and KNOWLEDGE to pull it off.

Its Not Magic!

So, What did we learn today?


Questions?

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Thank You

Ed Simpson, CCP, CPMM, LEED AP

• [email protected]


mailto:[email protected]

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