2017 SeaBEC Symposium Advancing Building Enclosures Beyond …€¦ · Solutions for minimizing...

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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”

Credit Eligibility:

1 - AIA CES LU|HSW

Credits will be reported to AIA by the SeaBEC organization.

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

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

• 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?

Parallel Path Heat flow

• 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

Addressing Lateral Heat Flow

Lateral Heat Flow

Parallel Path

With LateralHeat Flow

Overall Heat Loss

Additional heat loss due to the slab

oQQ slabQ

Overall Heat Loss

LQslab /The linear transmittance represents the additional heat flow because of the slab, but with area set to zero

Types of Thermal Transmittances

Linear

Clear Field

oUpsi chi

Overall Heat Loss

Total Heat Loss

LAUTQ o )(/

Heat Loss Due To

Anomalies

Heat Loss Due To

Clear Field+=

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

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

How can we meet the thermal performance challenges, as well as combustibility, structure, environmental separation, and durability requirements?

The Questions

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

North American Inclinations

Extra insulation at floor slab

Thicker walls with more exterior insulation

Clip and Rail System

Cavity Insulation

• 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

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

Methodology – Boundary Conditions

Differences in Boundary ConditionsPH (ISO) vs BETB Guide

• Exterior and Interior Temperatures

• Exterior and Interior Air Films

• Air Cavity Resistance

Methodology – Boundary Conditions

Differences in Boundary ConditionsPH (ISO) vs BETB Guide

• Exterior and Interior Temperatures

• Exterior and Interior Air Films

• Air Cavity Resistance

Methodology – Temperatures

PHI(ISO): -10oC BETBG: 0

PHI (ISO): 20oCBETBG: 1

PHI (ISO): ISO 10077BETBG: ASHRAE 1365

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

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

Methodology – Air Spaces

PHI (ISO): ISO 10077BETBG: ASHRAE HoF

PHI (ISO): R-1.0-1.2 (varies)

BETBG: R-0.9

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

2D versus 3D

ISO 14683

2D versus 3D

2D NFRC – 20 to 33%2D Modified – 10 to 15%

3D Model – 3%

Impact of Details

Source: Passive House Canada34

Impact of Details

= 0.05 W/m K

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.

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

Passive Commercial projects in Seattle

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

7.3.2 Transmittance Detail

7.3.2 Thermal Performance

7.3.2. Assembly Performance

Passive House – Window Detail

• Passive Thermal Performance data from Passive house detail, Patrick R.

Window Detail

• Passive Assembly Performance data from Passive house detail, Patrick R.

Window Detail

Passive House – Window DetailWindow Sill

Passive House – Window DetailWindow Head

Passive House – Window DetailWindow Jamb

• Passive Thermal Performance data from, Patrick R.

Window Detail Thermal Performance

• Passive Assembly Performance from Patrick Ropel

Window DetailAssembly Performance

5.2.22 Slab Edge Conventional Detail

5.2.22 Slab Edge ConventionalTransmittance Detail

5.2.22 Slab Edge, ConventionalThermal Performance

5.2.22 Slab Edge, ConventionalAssembly Performance

Passive House – Slab Edge Detail

• Thermal Performance, from Patrick Ropel

Slab Edge DetailThermal Performance

• Assembly Performance, from Patrick Ropel

Slab Edge DetailAssembly Performance

5.5.6 Parapet CapConventional Detail

5.5.6Parapet Cap Transmittance Detail

5.5.6 Parapet CapThermal Performance

5.5.6 Parapet CapAssembly Performance

5.5.9 Parapet Cap, Thermally BrokenConventional Detail

5.5.9 Parapet Cap, Thermally BrokenTransmittance Detail

5.5.9 Parapet Cap, Thermally BrokenThermal Performance

5.5.9 Parapet Cap, Thermally BrokenAssembly Performance

Passive House – Parapet Detail

Parapet

• PH Thermal Performance Data from Patrick

Parapet DetailThermal Performance

• PH Assembly Performance Data from Patrick

Parapet DetailAssembly Performance

7.6.4 Base of Wall, Below-Grade Conventional Detail

7.6.4 Base of Wall, Below-GradeTransmittance Detail

7.6.4 Base of Wall, Below-GradeThermal Performance

7.6.4 Base of Wall, Below-GradeAssembly Performance

Passive House – Base of Wall Detail

Base of Wall

Base of Wall DetailThermal Performance

Base of Wall DetailAssembly Performance

5.2.5 Typical BalconyConventional Detail

5.2.5 Typical BalconyTransmittance Detail

5.2.5 Typical Balcony5x Transmittance Detail

5.2.5 Thermal Performance

5.2.5 Assembly Performance

Passive House – Balcony Detail, Isometric

Intermittent Balcony

Balcony DetailThermal Performance

Balcony DetailAssembly Performance

Passive House – Balcony Detail cross section

Intermittent Balcony

Balcony Detail – Cross SectionThermal Performance

Balcony Detail – Cross SectionAssembly Performance

• Hygrothermal window sill

Solutions for an air-tight interior vapor retarder

Thank You!

ContactMedgar Marceau, MMarceau@morrisonhershfield.com

2017 SeaBEC Symposium Advancing Building Enclosures Beyond …€¦ · Solutions for minimizing...

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