BIMtopia

7.5.A Building Envelope Systems - Alessandro Kerr

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Alessandro Kerr

The following exercise will use the Autodesk Insight to explore how features of a building’s envelope can affect the predicted energy performance.

Baseline Case:

This is the benchmark comparison with the operating schedule and roof construction updated:

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Building Envelope Case:

The following building envelope changes resulted in a Predicted Mean EUI of less than 54 kBtu/ft2/yr. While there were some choices that could have saved slightly more energy, some changes seemed illogical and unreasonable ( 0% WWR ratios on any wall for example). The following changes take into account Thermal properties, Glazing %, Thermal properties of glazing, and window shading, and the specific change can be seen in the photo and caption:

Wall Construction: 14 inch ICF
Wall Construction: 14 inch ICF
Western Wall WWR of less than 15%
Western Wall WWR of less than 15%
Eastern Wall WWR - 30%
Eastern Wall WWR - 30%

Northern Wall WWR - Less than 50%
Northern Wall WWR - Less than 50%
Southern Wall WWR - No change
Southern Wall WWR - No change
East Window Glass - Triple Low-e
East Window Glass - Triple Low-e

North Window Glass - Triple Low-e
North Window Glass - Triple Low-e
West Window Glass - Triple Low-e
West Window Glass - Triple Low-e
East Window Shades - 2/3 Window Height
East Window Shades - 2/3 Window Height
EUI Mean Estimate based on Building Envelope Changes
EUI Mean Estimate based on Building Envelope Changes

Power and Lighting Measures

The following changes were implemented in the power and lighting measures category:

Plug Load Efficiency - 0.6W/sf
Plug Load Efficiency - 0.6W/sf
Lighting Efficiency - 0.3W/sf
Lighting Efficiency - 0.3W/sf
Daylighting and Occupancy Controls
Daylighting and Occupancy Controls

EUI Mean Estimate from Power and Lighting + Building Envelope Changes
EUI Mean Estimate from Power and Lighting + Building Envelope Changes

By adding the power and lighting measures to the building envelope improvements, the EUI can be reduced significantly.

Photovoltaic Panels

The following changes to the PV panel surface coverage, panel efficiency, and payback limit were explored:

PV - Panel Efficiency (20.4%)
PV - Panel Efficiency (20.4%)
PV - Payback Limit of 20-30 years
PV - Payback Limit of 20-30 years
PV - Surface Coverage of 90%
PV - Surface Coverage of 90%
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Overall, the predicted mean EUI can be driven below the ASHRAE, ARCH 2030, and even into the negative values by implementing PVs into the design strategy. The negative value suggests that this building could create more energy than it uses by implementing all these options.