Energy-Efficient Facilities: Building Envelope Design. Wall Systems. Copyright Materials. Course Description

Transcription

1 Energy-Efficient Facilities: Building Envelope Design Steve Easley Wall Systems Copyright Materials 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. The Wood Products Council 2014 The Wood Products Council is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES), Provider #G516. 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. Course Description This presentation will focus on cost-effective design recommendations for high performance building enclosures. It will explore why many buildings fail to perform as expected, and provide recommendations on envelope detailing, insulation and air sealing techniques for various climates, and information to include in specifications.

2 Learning Objectives Understand the technologies systems for designing high performance building enclosures. Select the best insulation and air barrier system for a given application. Write better specifications regarding air barriers, insulation and its installation. Understand the relationships between framing, thermal bridging air barriers, moisture vapor transmission, condensation, material permeability, and insulation selection. Rigid or semi-rigid exterior insulation Vapor permeable WRB forms the air barrier. The WRB is taped and sealed at joints and transitions Vertical wood strapping for cladding attachment, fastened to CLT through insulation with long screws Bug screen Self-adhered membrane head flashings Metal head flashing and closure flashing Self-adhered membrane sill flashings Metal sill flashing (with end dams) Drained and ventilated air space behind cladding fpinnovations

3 Click on Advanced Building systems Getting Enclosures Right Photo Mason Grant Consulting Courtesy B.S.C. Courtesy fp innovations

4 Energy Use in Schools K-12 $7.5 billion annually 2 nd Largest cost after salaries Heating cooling largest component Typ $1.25/sq ft Mid size district $ 1 over $1 million/yr. Focus on enclosure first. DOE, 2013, Touchstone Energy Historically Speaking Priorities were cost, strength, esthetics. Enclosure thermal performance was primarily an after thought to the structure. Energy was cheap Environmental issues were not a priority. R-2 R-2

5 Perspective from the Energy Information Service, DOE 4.7 million commercial building in the US only about 12,000 are 10 stories or greater Is this wall really R-20.5? Number of Floors One... 3,136 Two... 1,031 Three Four to Nine Ten or More Table 2. Types of Office Building, Number of Buildings, 2003, Released: September 2010 Glazing Ratio s

6 Impact of Windows Courtesy fp innovations Durability is Equally Important as energy Durability of the building enclosure is part of a sustainable building design Moisture is one of the major factors affecting durability in all buildings Energy and moisture are closely related Why Focus on the Building Enclosure First Reduces the heating and cooling system energy use, size and costs Is likely to last for the life of the structure Energy savings do not diminish with age Reduces the loads thus reduces design risk factors for HVAC Can manage moisture and increase building durability Can enhance occupant comfort and building IAQ

7 Building Enclosures Manage Water flow Air flow Heat flow & surfaces temps Moisture as a vapor Sound Control Fire separation 4 - Enclosure Control Layers Water- WRB s & Rain Screens Air- Air barriers, building wraps, air sealing Thermal- insulation or exsulation Vapor- vapor retarders Thermal Performance Factors Framing factor 25%+ ( opaque whole wall R-value frame & studs) Thermal Frame and Studs Wind washing Gaps in insulation Enclosure Thermal Performance Thermal performance is a 2 component process Conductive losses Solution Insulation Convective losses.solution Air sealing High performance enclosure = less loads = lower costs purchase, operation, maintenance.forever

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10 Typical Framing Spacing- Steel Typical Framing Spacing -Wood Courtesy fp innovations Typical Framing Factors Wood + CI Framing Factors Courtesy fp innovations Source - Oak Ridge National Labs

11 Wall Insulation Approaches Courtesy fp innovations Courtesy fp innovations Does staggering the studs improve performance? Does staggering the studs improve performance? Courtesy C.A.R.B.

12 Keys to a high performance system Factors Affecting Insulation Performance Stops air flow Not affected by moisture Stable R value Protects structure Compression Installed R-Values of Fiberglass

13 Specification Tips RESNET Specifications Insulation No voids/spaces, complete alignment with air barriers No compression Cavities filled Air sealing All Penetrations sealed Air testing ti The Goal Conductive losses (solved by proper insulation) RESNET Grade 1 Insulation Grades

14 Insulation Grades Insulation Grades Resources Resources

15 Effect of Compression Safety 1 st!!!

16 Note Heat Loss Between Floors

17 Wet-Spray Cellulose (Scrubbed) Wet-Spray Cellulose (Scrubbed) Wet-Spray Cellulose: Drying Time

18 Fiber Insulation Air Leakage Photo IR Thermogram Spectrum Infrared Ltd. Air Leakage Copyright along Steve the Easley, corner 2013 joint

19 Air Infiltration Standards

20 Solutions

21 Approaches to Air Aarriers and Continuous Insulation

22 Foam Shrinkage

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24 Quality Assurance Blower Door Testing Why Pressure Test Why Pressure Test You don t know until you measure Find leaks Helps insure quality and peformance Aids in Commissioning, LEED etc. Documents air tightness Uncontrolled Air Flow: Can cause moisture, mold problems Reduces durability & deteriorates materials Increases energy use Reduces comfort Impacts IAQ

25 This concludes The American Institute of Architects Continuing Education Systems Program