combined modeling efforts for the optimized facade: models, methods, materials presentation

Visualizing the impact of Thermal Bridging on the

design of High Performance Buildings

Stéphane HoffmanMorrison Hershfield

December 4th, 2015

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Thermal Bridging

ASHRAE 1365- RP BC Hydro BETBG

Presentation Overview

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Thermal Bridging 101

Data & Findings

Applications

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Thermal Bridging 101

• Highly conductive material that by-passes insulation layer

• Areas of high heat transfer

• Can greatly affect the thermal performance of assemblies

Effective Thermal Resistance

What is a Thermal Bridge?

Parallel Path Heat flow

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Utotal

Area weighted average of un-insulated assemblies

Addressing Lateral Heat Flow

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Overall Heat Loss

Additional heat loss

due to the slab

oQQ slabQ

Overall Heat Loss

LQslab /=ΨThe linear transmittance

represents the additional heat

flow because of the slab, but

with area set to zero

The Guide

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Applications

Evaluating Impact of Details

Determine Whole Building

Heat Loss

Shelf angle

Window Transition

Parapet

Slab

Corner

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Heat Flow Summary Example

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Opaque Wall Thermal Performance

Summary Example

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Visualization Tool

for Parametric Modeling

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Parametric Visualization Tool

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Parametric Visualization Tool

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Parametric Visualization Tool

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Parametric Visualization Tool

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Parametric Visualization Tool

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Parametric Visualization Tool

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Parametric Visualization Tool

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Parametric Visualization Tool

Future Trends

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• Increasingly difficult to

ignore thermal bridging

at intersections of

assemblies

• Move beyond simply

adding “more insulation”

• Better able to account

for thermal performance

of envelope

The Future

Questions