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2017 SeaBEC Symposium
Advancing Building Enclosures Beyond Code Conformance
Medgar Marceau, PEPrincipal, Senior Building Science Engineer
May 16, 2017
AIAMH123
“Passive House and Commercial Construction -The Evolution of Residential Passive House Building Standards and the
Application to Commercial Construction”
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Credit Eligibility:
1 - AIA CES LU|HSW
Credits will be reported to AIA by the SeaBEC organization.
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There is a large knowledge base of how to build durable residential buildings that meet the Passive House standard.
However, there are few examples of commercial buildings meeting Passive House.
This presentation will help bridge the knowledge gap between residential and commercial Passive House construction.
Couse Description
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Acknowledging the challenges in translating Passive House to Passive Commercial
Solutions for minimizing thermal bridging in commercial construction
Thermally efficient at-grade and below-grade transitions
Using 2-D and 3-D simulation tools to evaluate hygrothermal performance
Solutions for an air-tight interior vapor retarder
Learning Objectives
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• Highly conductive material that by-passes insulation layer• Areas of high heat transfer• Can greatly affect the thermal performance of assemblies
What is a Thermal Bridge?
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Parallel Path Heat flow
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total
• Area-weighted average of un-insulated assemblies• In 2015 WA and Seattle Energy Codes• Does not tell the whole story
• Parallel path doesn’t tell the whole story• Many thermal bridges don’t abide by “areas” ie: shelf
angle• Lateral heat flow can greatly affect the thermal
performance of assemblies
Thermal Bridging
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Addressing Lateral Heat Flow
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Lateral Heat Flow
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Parallel Path
With LateralHeat Flow
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Overall Heat Loss
Additional heat loss due to the slab
oQQ slabQ
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Overall Heat Loss
LQslab /The linear transmittance represents the additional heat flow because of the slab, but with area set to zero
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Types of Thermal Transmittances
Point
Linear
Clear Field
oUpsi chi
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Overall Heat Loss
Total Heat Loss
LAUTQ o )(/
Heat Loss Due To
Anomalies
Heat Loss Due To
Clear Field+=
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Why is Passive House criteria so much lower than the categories in the BETB?
The QuestionsPsi IP Psi Metric
ᵠ ᵠ(BTU/hr.ft.°F) (W/mK)
Thermal Bridge Free 0.006 0.0100.012 0.0200.017 0.030
Typical Good Detail 0.023 0.0400.029 0.0500.035 0.060
Typical Ok Detail 0.040 0.0700.046 0.0800.052 0.0900.058 0.100
Poor Detail 0.064 0.1100.069 0.1200.075 0.1300.081 0.140
Bad Detail 0.087 0.1500.092 0.1600.098 0.1700.104 0.1800.110 0.190
Anything Past Here Brutal 0.116 0.2000.121 0.2100.127 0.2200.133 0.2300.139 0.2400.144 0.2500.150 0.2600.156 0.2700.162 0.2800.168 0.2900.173 0.3000.179 0.310
Anything Past Here is Brutal
The Questions
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How does PHPP predictions compare to dynamic models, in the context of recent BC policy work, thermal comfort, and when might both tools be required on project?
The Questions
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How can we meet the thermal performance challenges, as well as combustibility, structure, environmental separation, and durability requirements?
The Questions
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1. Address questions about different methodologies for quantifying thermal bridging
2. Identify the key differences between static and dynamic simulation when assessing predicted building performance;
3. Identify the key differences in testing protocols for Heat Recovery Ventilators;
4. Provide design guidance and examples of how Part 3 buildings could meet high levels of performance similar to Passive House in BC
Objectives
European Passivhaus
Is different
JambHeadSillR-44
R-6.8
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North American Inclinations
Extra insulation at floor slab
Thicker walls with more exterior insulation
Clip and Rail System
Cavity Insulation
R-38
• What is being considered in Alaska and in New York for Passive House is an indication of a mainstream response
PNW Construction Practice
Condensation risk Occupant comfort High effective R-value Compressed
construction duration
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Accuracy Expectations
ISO 14683:2007, section 5.1
• Numerical calculations, typically ±5%
• Thermal bridge catalogues, typically ±20%
• Manual calculations, typically ±20%
• Default values, typical accuracy 0 to 50%
Intent is to be conservative
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Methodology – Boundary Conditions
Differences in Boundary ConditionsPH (ISO) vs BETB Guide
• Exterior and Interior Temperatures
• Exterior and Interior Air Films
• Air Cavity Resistance
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Methodology – Boundary Conditions
Differences in Boundary ConditionsPH (ISO) vs BETB Guide
• Exterior and Interior Temperatures
• Exterior and Interior Air Films
• Air Cavity Resistance
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Methodology – Temperatures
PHI(ISO): -10oC BETBG: 0
PHI (ISO): 20oCBETBG: 1
PHI (ISO): ISO 10077BETBG: ASHRAE 1365
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Methodology – Air Films
CeilingPHI (ISO): 10 W/m2
BETBG: 9.3 W/m2
FloorPHI (ISO): 5.9 W/m2
BETBG: 6.1 W/m2
Exterior PHI (ISO): 25 W/m2
BETBG: 34 W/m2
PHI (ISO): ISO 6946BETBG: ASHRAE HoF
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Methodology – Air Films – R-Value
FloorPHi (ISO): R-0.96BETBG: R-0.93
CeilingPHi (ISO): R-0.57BETBG: R-0.61
Exterior PHi (ISO): R-0.23BETBG: R-0.17
PHi (ISO): ISO 6946BETBG: ASHRAE HoF
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Methodology – Air Spaces
PHI (ISO): ISO 10077BETBG: ASHRAE HoF
PHI (ISO): R-1.0-1.2 (varies)
BETBG: R-0.9
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Methodology – Overall Values
Clear Field U-Value
PHI (ISO): 0.318 W/m2KBETBG: 0.323 W/m2K
Slab Psi-Value
PHI (ISO): 0.024 W/mKBETBG: 0.023 W/mK
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2D versus 3D
ISO 14683
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2D versus 3D
2D NFRC – 20 to 33%2D Modified – 10 to 15%
3D Model – 3%
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Impact of Details
Source: Passive House Canada34
Impact of Details
= 0.05 W/m K
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Impact of Details
• Window interface – triple glazed window, high levels of insulation, and mitigation of thermal bridging. Highlight sill, jamb, and head. Compare to overall transmittance for both detailed and simplified geometry.
• Intermediate floor – higher levels of insulation, flashing, and how insulation in the stud cavity impacts 2D versus 3D flow assumptions.
• Base of wall – thermal break and higher levels of insulation
• Balcony – intermittent supported.
• Parapet – higher levels of insulation and 2D versus 3D assumptions.
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Illustrated Guide
• Design guidance suited to BC’s climate and construction practices
• Challenges and opportunities around combustibility, structure, environmental separation, and durability
• Energy modeling considerations for Part 3 buildings equivalent to or approaching Passive House standard
• Outline how N.A. HRVs can be used in Passive House certified buildings
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Passive Commercial projects in Seattle
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March 23, 2017 - DJC
How 'negawatts' help the buildingindustry fight climate change
March 22, 2017 - DJC
SolHaus wins green award
January 11, 2017 - DJC
This Lower Queen Anne apartment complex has ‘passive house' design
September 13, 2016 - DJC
East Pike apartments will meet Passive House energy standards
City’s Renewable City Strategy:British Columbia’s building trends
affecting the Pacific Northwest markets.
THAT Council direct staff to build all new City-owned and Vancouver Affordable Housing Agency (VAHA) projects to be Certified to the Passive House standard or alternate zero emission building standard, and use only low carbon fuel sources, in lieu of certifying to LEED Gold unless it is deemed unviable by Real Estate and Facilities Management, or VAHA respectively, in collaboration with Sustainability and report back with recommendations for a Zero Emissions Policy for New Buildings for all City-owned and VAHA building projects by 2018. City of Vancouver RR-2, July 5, 2016
7.3.2 Conventional Window Detail
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7.3.2 Transmittance Detail
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7.3.2 Thermal Performance
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7.3.2. Assembly Performance
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Passive House – Window Detail
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• Passive Thermal Performance data from Passive house detail, Patrick R.
Window Detail
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• Passive Assembly Performance data from Passive house detail, Patrick R.
Window Detail
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Passive House – Window DetailWindow Sill
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Passive House – Window DetailWindow Head
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Passive House – Window DetailWindow Jamb
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• Passive Thermal Performance data from, Patrick R.
Window Detail Thermal Performance
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• Passive Assembly Performance from Patrick Ropel
Window DetailAssembly Performance
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5.2.22 Slab Edge Conventional Detail
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5.2.22 Slab Edge ConventionalTransmittance Detail
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5.2.22 Slab Edge, ConventionalThermal Performance
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5.2.22 Slab Edge, ConventionalAssembly Performance
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Passive House – Slab Edge Detail
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• Thermal Performance, from Patrick Ropel
Slab Edge DetailThermal Performance
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• Assembly Performance, from Patrick Ropel
Slab Edge DetailAssembly Performance
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5.5.6 Parapet CapConventional Detail
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5.5.6Parapet Cap Transmittance Detail
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5.5.6 Parapet CapThermal Performance
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5.5.6 Parapet CapAssembly Performance
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5.5.9 Parapet Cap, Thermally BrokenConventional Detail
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5.5.9 Parapet Cap, Thermally BrokenTransmittance Detail
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5.5.9 Parapet Cap, Thermally BrokenThermal Performance
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5.5.9 Parapet Cap, Thermally BrokenAssembly Performance
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Passive House – Parapet Detail
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Parapet
• PH Thermal Performance Data from Patrick
Parapet DetailThermal Performance
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• PH Assembly Performance Data from Patrick
Parapet DetailAssembly Performance
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7.6.4 Base of Wall, Below-Grade Conventional Detail
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7.6.4 Base of Wall, Below-GradeTransmittance Detail
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7.6.4 Base of Wall, Below-GradeThermal Performance
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7.6.4 Base of Wall, Below-GradeAssembly Performance
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Passive House – Base of Wall Detail
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Base of Wall
• PH Thermal Performance Data from Patrick
Base of Wall DetailThermal Performance
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• PH Assembly Performance Data from Patrick
Base of Wall DetailAssembly Performance
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5.2.5 Typical BalconyConventional Detail
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5.2.5 Typical BalconyTransmittance Detail
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5.2.5 Typical Balcony5x Transmittance Detail
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5.2.5 Thermal Performance
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5.2.5 Assembly Performance
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Passive House – Balcony Detail, Isometric
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Intermittent Balcony
• PH Thermal Performance Data from Patrick
Balcony DetailThermal Performance
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• PH Assembly Performance Data from Patrick
Balcony DetailAssembly Performance
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Passive House – Balcony Detail cross section
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Intermittent Balcony
• PH Thermal Performance Data from Patrick
Balcony Detail – Cross SectionThermal Performance
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• PH Assembly Performance Data from Patrick
Balcony Detail – Cross SectionAssembly Performance
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• Hygrothermal window sill
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Solutions for an air-tight interior vapor retarder
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