Phoenix Convention Center Phoenix, Arizona Air Barrier Technologies Energy TechnologiesWindows and Building Envelope Technologies Diana Hun, PhD Oak Ridge

Phoenix Convention Center • Phoenix, Arizona

Air Barrier Technologies

Energy Technologies Windows and Building Envelope Technologies

Diana Hun, PhDOak Ridge National Laboratory

August 12, 2015

Energy Exchange: Federal Sustainability for the Next Decade2

Air Leakage

Accounts for 10% of energy used in buildings

Office of Energy Efficiency and Renewable Energy, Building Energy Data Book

Transportation28 Quads

Industrial30 Quads

Buildings40 Quads

Air Leakage4 Quads

US Primary Energy Consumption98 Quads


Air Sealing in Commercial Buildings

• ~800 TBtu staged energy savings in 2030 from maximum adoption• 2.5 years staged payback

Air-Sealing Systems (C)

(R) Residential (C) Commercial

Windows and Building Envelope Research and Development: Roadmap for Emerging Technologies (DOE 2014)


• Air barrier (ASTM E2178, E2357, E779)– Controls airflow– Degree of water vapor control varies

• Water vapor retarder (ASTM E96)– Controls water vapor flow– Class I: < 0.1 perm foil-faced isocyanurate– Class II: 0.1 < perm 1 1” extruded polystyrene– Class III: 1 < perm 10 latex paint

• Water-resistive barrier (aka weather barrier; ASTM E331) – Controls water flow

Definitions


• Low air permeance– Varies with building code/standard

• Continuous over the entire building envelope– Seal gaps around penetrations (install before cladding)– Seal wall-to-roof joint– Seal wall-to-foundation joint

• Withstands forces during and after construction

• Durable over expected lifetime of building

Air Barrier System Requirements


• PBS-P100: Facilities standards for the Public Buildings Service– Baseline < 2 L/s/m2 @ 75 Pa– Tier 1 < 1.25 L/s/m2 @ 75 Pa– Tier 2 < 0.75 L/s/m2 @ 75 Pa– Tier 3 < 0.5 L/s/m2 @ 75 Pa

• IECC 2012 options– Material < 0.02 L/s/m2 @ 75 Pa (ASTM E2178)

– Assembly < 0.2 L/s/m2 @ 75 Pa (ASTM E2357)

– Envelope < 2 L/s/m2 @ 75 Pa

• Army Corp of Engineers– Envelope < 1.25 L/s/m2 @ 75 Pa

Air Permeance Requirements

Blower door test (ASTM E779/E1827)




Air Barrier Effects

Emmerich and Persily 2014

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0.7

>13.

9

13.9

13.2

12.5

11.8

11.1

10.49.7

9.0

8.3

7.6

6.9

6.3

5.6

4.9

4.2

3.5

2.8

2.1

1.4

Envelope Leakage at 75 Pa (L/s/m2)

Buildings with air barriers Buildings without air barriers

50

45

40

35

30

25

20

15

10

5

0


Air Barrier Types for Commercial Buildings


• Similarities– Can serve as air and water barrier, and drainage plane– Many manufacturers require installation training

• Differences– Material cost– Installation

• Procedure, training, workmanship skills, time, cost• Temperature• Location: interior or exterior side of wall cavity

– Vapor permeance– Thermal resistance

Overall Comparison


• Most products have high vapor permeance (5 to 50 perms)

• Require screws with 2” caps • Joints are typically sealed with tape– Should be rolled– Priming may be required on concrete, masonry and fiber faced gypsum board

Mechanically-Fastened Membranes

Fasteners with 2” caps


• Moderate vapor permeance (0.1 to 1 perm)

• Reduce thermal bridging when on outer side of wall cavity• Can replace the exterior sheathing• Requires screws with 2” caps • Joints are typically sealed with tape– Should be rolled

Insulating Sheathings

Foil-faced polyisocyanurate boards Extruded polystyrene boards Fasteners with 2” caps


• Available with low and high vapor permeance (0.03 to 30 perms)

• Asphalt-based membranes require substrates to be primed – Primer must cure before membrane installation

• Some non-asphalt-based membranes do not require priming• Low temperature products available• Membrane should be rolled

Self-Adhered Membranes

Priming before installation of asphalt-based membrane Primer-less self-adhered membrane


• Available with low and high vapor permeance (0.1 to 30 perms)

• Relatively fast installation with roller or sprayer• May require personal protective equipment• Low VOC products available• Low temperature products available• Potential concerns

– Overspray– Minimum thickness

Fluid-Applied Membranes


Closed-cell spray polyurethane foam (SPF) • Moderate vapor permeance• Reduces thermal bridging when on outer side of wall cavity• Relatively fast installation• Installers must wear personal protective equipment• Adequate ventilation should be provided during installation• Building should not be occupied during installation• Overspray and non-uniform thickness are potential concerns

Spray-Applied Foam


Latest Technologies


Reduce Labor and Installation Time

Installed with gun and putty knife or spreader Spray applied

Liquid Flashings

Primer-Less Self-Adhered Membranes


Case Study: Wall Retrofit Solutions


• Develop suite of wall retrofit solutions• Exceed ASHRAE 90.1-2010• Suitable for masonry construction

– Common in northeast– Preserve existing façade– Interior retrofit

• 10 to 15 years payback time• Evaluations based on

– Simulations– Lab tests – Field tests

Objectives

Brick façade

2” Air gap

8” CMU

R11 fiberglass insulation between steel studs

Drywall


Retrofit Scenarios

Solution criteria Scenario Potential retrofitCost effectiveRetain existing wall 1 2” foam board over existing wall

Semi-cost effectiveRemove existing insulation

2 6” open-cell SPF within stud cavity

3 5” closed-cell SPF within stud cavity

Energy efficientRemove existing insulation and studs

4 3.5” cellulose + 2.5” cont. cellulose

5 2” closed-cell SPF + 1.5” cont. closed-cell SPF

6 3.5” cellulose + 2” cont. closed-cell SFP

7 3.5” cellulose + 1.5” cont. closed-cell SPF

8 2.5” foam board w/ air barrier

9 2.5” foam board w/o air barrier


Evaluation Parameters

Relevant parameters per panel of industry experts

Level of importance per panel of industry experts Data

Cost-effectiveness 35% Cost analysis

Moisture management/durability 20% Simulations

Thermal performance 18% Simulations

Air leakage 12% Literature

Disruptiveness/Constructability 9% Industry assumptions

Indoor air quality 6% Simulations


Selected Retrofit Scenarios

Solution criteria Scenario Potential retrofitCost effectiveRetain existing wall 1 2” foam board over existing wall

Semi-cost effectiveRemove existing insulation

2 6” open-cell SPF within stud cavity

3 5” closed-cell SPF within stud cavity

Energy efficientRemove existing insulation and studs

4 3.5” cellulose + 2.5” cont. cellulose

5 2” closed-cell SPF + 1.5” cont. closed-cell SPF

6 3.5” cellulose + 2” cont. closed-cell SFP

7 3.5” cellulose + 1.5” cont. closed-cell SPF

8 2.5” foam board w/ air barrier

9 2.5” foam board w/o air barrier


• ORNL’s Flexible Research Platform• Monitoring– Building envelope– HVAC

• Calibrated model• Retrofit– Two rooms with each of the solutions– Collect data for 1 year – Improve simulation results– Issue guidelines in April 2016

Field Evaluation


Thanks for your attention

Documents

Phoenix Convention Center Phoenix, Arizona Air Barrier Technologies Energy TechnologiesWindows and Building Envelope Technologies Diana Hun, PhD Oak Ridge