Cooling Climates Technologies Task Force Meeting Fenestration portion

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Cooling Climates TechnologiesTask Force
Meeting(Fenestration portion)

• August 21, 2001Howard WiigState of Hawaii
• Erik Kolderup, PEEley Associates

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Goal of Work

• Develop commercial building guidelines
• Identify potential energy code upgrades

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Todays Topics

• High Performance Windows
• Energy impact
• Peak load impact (AC size)
• Lifecycle cost results
• Compare results to current energy code
• Discuss future code options
• Dehumidification
• Relative performance of different systems
• Discuss guideline contents
• UV-Lamp Summary

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High Performance Windows

• Low solar heat gain coefficient (SHGC)
• High visible light transmittance (Tvis)
• Technologies
• Coatings
• Tints

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Specularly-Selective Glazings
Blue or green tint
Heat Mirror
Low-e coatings
Someretrofit window films
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Window Energy Impact

• Computer simulation
• DOE2.1E program
• Honolulu weather data full year
• Window area 5, 10, 15, 20, 30, 50, 75 of wall
• 12 glazing types
• 8 orientations N, NE, E, SE, S, SW, W, NW
• With and without interior shades
• With daylighting controls 70 footcandle
  setpoint
• Typical office building
• Packaged single-zone DX systems, 73F setpoint

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Glazing Types Considered
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Glazing Cost Assumptions
These are cost to contractor on mainland. For
total markup of about 70 for shipping, and
typical contractor markup.
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Example Fenestration Electricity Impact
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Whole BuildingElectricity Consumption
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Whole BuildingElectricity Consumption (Zoom)
WWR 0 to 0.20
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Peak Cooling Load
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Lifecycle Cost Factors

• Window cost
• Electricity cost
• 0.12/kWh
• Series present worth factor 12
• 1 kWh/yr savings 1.44 present value
• AC cost
• 500 per ton savings for reduced peak load

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Life Cycle Cost Equation
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Whole BuildingLifecycle Cost
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Whole BuildingLifecycle Cost (Zoom)
WWR 0 to 0.20
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Lowest Lifecycle Cost Summary Table
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Current Window Criteria for Hawaii
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Comparison to Current Code
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Comparison to California 2001 Code
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Lifecycle Cost West
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Lifecycle Cost North
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Lifecycle Cost By OrientationHigh Perf Tint,
Low-E Glass
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Lifecycle Cost By OrientationSingle, Clear Glass
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Lifecycle Cost with and w/o Interior Shades
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Lifecycle Cost With Interior Shades Whole
Building
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Lifecycle Cost without Shades(for comparison)
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Lifecycle Cost With Interior Shades Whole
Building (Zoom)
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Lifecycle Cost without Shades(for comparison)
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Lifecycle Cost Summary Table
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Some Window Code Issues

• Separate requirements by orientation?
• Exceptions for shaded windows?
• Credit for shading devices (overhangs,)
• Upper limit on window area?
• Requirement varying by window area?
• Credit for interior shades?
• Credit for high light transmission?
• Simple table format for requirements?
• Economic criteria for setting requirements?

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Window Guideline Issues

• What information is useful for designers?
• Energy impact
• Peak load impact
• Life-cycle cost
• First cost impact
• Daylighting/glare impact
• What format is best?
• Graphs
• Tables
• ???