Combined Modeling Efforts for the Optimized Facade: Models, Methods, Materials presentation

Visualizing the impact of Thermal Bridging on the design of High Performance Buildings StĂŠphane Hoffman Morrison Hershfield

December 4th, 2015

Thermal Bridging

ASHRAE 1365- RP 2

BC Hydro BETBG

Presentation Overview

1 Thermal Bridging 101 2 Data & Findings 3 Applications

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Thermal Bridging 101

Effective Thermal Resistance What is a Thermal Bridge?

• Highly conductive material that by-passes insulation layer • Areas of high heat transfer • Can greatly affect the thermal performance of assemblies

Parallel Path Heat flow

Utotal

Area weighted average of un-insulated assemblies 6

Addressing Lateral Heat Flow

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Overall Heat Loss

Q

Qo

Qslab

Additional heat loss due to the slab

Overall Heat Loss

Ψ = Qslab / L The 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 Corner Shelf angle

Parapet

Window Transition Slab

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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

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

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Future Trends

The Future • 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

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Questions