J.B. Speed School of Engineering University of Louisville KEEPS Energy Management Toolkit Step 2: Assess Performance & Opportunities Toolkit 2J: Building Envelope Kentucky Energy Efficiency Program for Schools KEEPS Energy Management Toolkit Step 2 Assess Performance & Opportunities Toolkit 2 J Building Envelope

2 KPPC Kentuckys Resource Center for Environmental Sustainability KEEPS Energy Management Toolkit Toolkit 2J: Building Envelope KEEPS Energy Management Toolkit Toolkit 2 J Building Envelope 2

3 KPPC Kentuckys Resource Center for Environmental Sustainability 3 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

4 KPPC Kentuckys Resource Center for Environmental Sustainability Building Envelope Overview Definition Importance Heat loss/retention Low-cost/no cost fixes Fixes requiring capital investment 4

5 KPPC Kentuckys 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 5

6 KPPC Kentuckys 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 6

7 KPPC Kentuckys Resource Center for Environmental Sustainability Understanding Heat Transfer 7

8 KPPC Kentuckys 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. 8

9 KPPC Kentuckys Resource Center for Environmental Sustainability Types of Heat Movement 9

10 KPPC Kentuckys Resource Center for Environmental Sustainability Conductive Heat Transfer 10

11 KPPC Kentuckys Resource Center for Environmental Sustainability Heat Loss Illustrated 11

12 KPPC Kentuckys Resource Center for Environmental Sustainability A Closer Look at Heat Loss 12

13 KPPC Kentuckys 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 13

14 KPPC Kentuckys 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 14

15 KPPC Kentuckys 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 15

16 KPPC Kentuckys 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 16

17 KPPC Kentuckys Resource Center for Environmental Sustainability Easy Fixes 17

18 KPPC Kentuckys Resource Center for Environmental Sustainability Look Closer for Best Opportunities 18

19 KPPC Kentuckys 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 19

20 KPPC Kentuckys 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 20

21 KPPC Kentuckys 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 21

22 KPPC Kentuckys Resource Center for Environmental Sustainability Resources Available for download from the KEEPS Toolkit Library 22

J.B. Speed School of Engineering University of Louisville End of Presen tation (502) 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.