Practice Exercise: Building Envelope Systems

Your Name
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Design task 1: Analyze the Initial Building Model

Before setting the baseline assumptions:

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(I am not sure why I didn’t get 81.3 as the initial value as the assignment’s description stated. I double checked the settings and ran the analysis twice but still got 75.6.)

Set baseline assumptions: 1. Operating Schedule to 12/5; 2. Roof Construction to R38.

After setting the baseline assumptions, the EUI dropped from 75.6 kBtu/ft^2/yr to 54.1 kBtu/ft^2/yr.

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Design task 2: Use Insight to Explore the Impact of Building Envelope-Related Design Decisions

By using the baseline assumptions and adjusting the building envelope-related design measures, the predicted mean EUI is reduced to 48.4 kBtu/ft^2/yr which is less than 54 kBtu/ft^2/yr.

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Factors (also my recommendations) considered:

  • Thermal Properties of Wall Surface (Wall Construction) for all orientations
    • R38 wood
  • Glazing % (Window-to-Wall Ratio) for each orientation (North, South, East, West)
    • North: 50%
    • South: 80%
    • East: 15%
    • West: 15%
  • Thermal Properties of Glazing Surfaces for each orientation
    • North: Double Low E
    • South: Triple Low E
    • East: Double Low E
    • West: Double Low E
  • Window Shading amount for each orientation
    • North: ½ Win Height
    • South: ½ Win Height
    • East: ½ Win Height
    • West: ½ Win Height

Design task 3: Use Insight to Explore the Potential Impact of Power and Lighting Measures (versus Building Envelope Measures)

By using the baseline assumptions and adjusting only the power and lighting measures, the predicted mean EUI is 44.3 kBtu/ft^2/yr (which is less than 54 kBtu/ft^2/yr), showing that the impact of power and lighting measures that I chose is more significant than the impact of the building envelope measures.

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Factors (also my recommendations) considered:

  • Plug Load Efficiency (the equipment and appliances that draw power)
    • 6W/sf & 1.0W/sf
  • Lighting Efficiency (based on the efficiency of the lighting fixtures)
    • 3W/sf & 0.7W/sf
  • Daylighting & Occupancy Controls
    • Daylighting & occupancy controls

By adding these power and daylighting measures on top of the building envelope-related measures, the predicted mean EUI is reduced to 38.6 kBtu/ft^2/yr, which is less than 54 kBtu/ft^2/yr.

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Design task 4: Use Insight to Explore the Benefits of Adding Photovoltaic Panels to Your Design

By using the baseline assumptions and adjusting only the photovoltaic panels measures, the predicted mean EUI is 12.5 kBtu/ft^2/yr, showing that the impact of PV panel measures that I chose is much more significant than the impacts of the building envelope, power, and daylighting measures.

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Factors (also my recommendations) considered:

  • Surface Coverage
    • 90%
  • Panel Efficiency
    • 4%
  • Payback Limit (how many years you will allow for the panels to pay for themselves
    • 20 yr to 30 yr

By adding these PV panel measures on top of the building envelope-related measures and the power and daylighting measures, the overall predicted mean EUI is reduced to -3.05 kBtu/ft^2/yr, which achieves the Architecture 2030 goal and shows that the building system produces more energy than it needs.

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