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J.B. Speed School of Engineering University of Louisville
KEEPS Energy Management ToolkitStep 2: Assess Performance & OpportunitiesToolkit 2J: Building Envelope
Kentucky Energy Efficiency Program for Schools
KEEPS EnergyManagement Toolkit
Step 2
Assess Performance & Opportunities
Toolkit 2J
Building Envelope
2KPPC Kentucky’s Resource Center for Environmental Sustainability
KEEPS Energy Management ToolkitToolkit 2J: Building Envelope
KEEPSEnergyManagementToolkit
Toolkit 2JBuilding Envelope
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3KPPC Kentucky’s Resource Center for Environmental Sustainability3
7-Step Energy Management Process
1. Make the Commitment
2. Assess Performance and Opportunities
3. Set Performance Goals
4. Create an Action Plan
5. Implement the Action Plan
6. Evaluate Progress
7. Recognize Achievements
4KPPC Kentucky’s Resource Center for Environmental Sustainability
Building Envelope Overview
Definition
Importance
Heat loss/retention
Low-cost/no cost fixes
Fixes requiring capital investment
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5KPPC Kentucky’s Resource Center for Environmental Sustainability
What is the Building Envelope?
Separates interior and exterior of a building• Floor• Foundation• Walls• Ceiling• Roof
Components that penetrate the building• Windows• Doors• Vents• Electrical Boxes• Pipes
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6KPPC Kentucky’s Resource Center for Environmental Sustainability
Building Envelope Impacts
• Barrier between conditioned inside air and unconditioned outside air
• Significant impact on passive heat lost and gained by the building
• Passive heat transfer increases the load on the HVAC system
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7KPPC Kentucky’s Resource Center for Environmental Sustainability
Understanding Heat Transfer
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8KPPC Kentucky’s Resource Center for Environmental Sustainability
From Hot to Cold
Heat flows from hotter areas to colder areas.
The bigger the temperature difference the faster it moves.
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9KPPC Kentucky’s Resource Center for Environmental Sustainability
Types ofHeat
Movement
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10KPPC Kentucky’s Resource Center for Environmental Sustainability
Conductive Heat Transfer
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11KPPC Kentucky’s Resource Center for Environmental Sustainability
Heat Loss Illustrated
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12KPPC Kentucky’s Resource Center for Environmental Sustainability
A Closer Look at Heat Loss
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13KPPC Kentucky’s Resource Center for Environmental Sustainability
Infiltration Through Gaps
• Leaks around windows and doors• Broken window seals, latches and panes• Open doors and windows• Old windows and doors• Vents that do not close properly, if at all • Leaky heating and cooling ducts• Inadequate insulation (thin, sparse, gaps)• Leaks between floor, wall, ceiling, roof
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14KPPC Kentucky’s Resource Center for Environmental Sustainability
Quantifying Infiltrative Heat Loss
• Can calculate infiltrative heat loss from single measurable opening
• Cannot calculate total infiltration because of gaps in inaccessible building cavities
• For high-cost projects, heat loss can be quantified through blower door analysis
• Use thermal imaging of heat loss for prioritization
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15KPPC Kentucky’s Resource Center for Environmental Sustainability
Solar Radiation
• Orientation of building• Exterior colors• Shade trees or other structures• Landscaping• Window awnings or light shelves• Window films or shades
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16KPPC Kentucky’s Resource Center for Environmental Sustainability
Low-cost/No-cost Fixes
• Weather-seal doors, windows, electrical outlets, other openings
• Repair dampers • Keep windows and doors closed• Use kitchen exhaust fan only when
needed• Repair leaks in ductwork
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17KPPC Kentucky’s Resource Center for Environmental Sustainability
Easy Fixes
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18KPPC Kentucky’s Resource Center for Environmental Sustainability
Look Closer for Best Opportunities
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19KPPC Kentucky’s Resource Center for Environmental Sustainability
Fixes Requiring Capital Investments
• Improve insulation in floors, walls, attics• Replace windows and doors• Energy-efficient roof• Change the color of exterior walls• Add awnings or light shelves • Add window films and shades• Improve landscaping
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20KPPC Kentucky’s Resource Center for Environmental Sustainability
Evaluating Return on Investment
• Obtain reasonable estimates of heat lost or gained
• Investigate material and labor costs
• Determine time of payback
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21KPPC Kentucky’s Resource Center for Environmental Sustainability
Building Envelope Summary
• Building envelope is the barrier between conditioned and unconditioned space
• Heat transfer generally increases the load on the HVAC system
• Materials used and tightness of the structure affect the rate of heat transfer
• Conduct a thorough analysis to quantify energy wasted before implementing large capital projects
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22KPPC Kentucky’s Resource Center for Environmental Sustainability
Resources
• Available for download from the KEEPS Toolkit Library• http://www.kppc.org/KEEPS
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J.B. Speed School of Engineering University of Louisville
End of Presentation
(502) 852-0965
www.kppc.org/KEEPS
Kentucky Energy Efficiency Program for Schools
KEEPS is funded by the American Recovery and Reinvestment Act through the combined efforts of the Kentucky Department for Energy Development and Independence, the U.S. Department of Energy and KPPC.