A Parametric Study on Retrofitting Existing Building Envelope using EIFS over-cladding

Transcription

1 Using Your Building s Envelope to Minimize Heating and Cooling Load A Parametric Study on Retrofitting Existing Building Envelope using EIFS over-cladding Chris Norris, P.E., LEED AP Walter P Moore August 16, 2017 Tampa Convention Center Tampa, Florida

2 Outline Learning Objectives Background Why is it important? Energy Study Scope What did we do? Limitations What did we not do? Energy Model Input The nuts and bolts Energy Simulation Results What we found out Conclusion Key Findings 2

3 Learning Objectives Understand opportunities for building enclosure energy upgrades for building enclosure of pre-1980's vintage office buildings Identify key factors for optimization of building enclosure energy performance Understand the influence of climate and building geometry on energy improvement opportunities Identify the relative benefits of Pre-fabricated Exterior Insulation Finishing Systems (EIFS) over-cladding as a building enclosure retrofit option for reducing energy consumption. 3

4 Background 4

5 Background 5

6 Background 6

7 Background Huge opportunity to improve sustainability and reduce energy consumption. 7

8 Energy Study Scope EIFS Pre-Fabrication Panel over-cladding system for retrofitting existing building envelope wall systems Parametric study to compare relative benefits EIFS overclad Re-roofing Window replacement 8

9 EIFS Retrofits 9

10 EIFS Retrofits 10

11 EIFS Retrofits 11

12 Energy Study Scope Three building geometries Office Building equest Models: 3-Story vs. 6-Story vs. 12-Story 12

13 Energy Study Scope Three climate zones Atlanta (3A)m Baltimore (4A), Chicago (5A) 13

14 Energy Study Scope Modeled energy consumption by cost for: Space heating Space cooling Ventilation 14

15 Limitations Study limited to the effectiveness of building enclosure retrofits No modifications to HVAC Systems Calculated energy consumption limited to HVAC energy Domestic water heating, lighting, and other miscellaneous energy consumption are not included in this study. 15

16 Energy Model Input Baseline Building Geometry Building Geometry Gross SF Aspect Ratio WWR Three Story 53, % Six Story 230, % Twelve Story 460, % Note: Existing pre-1980 construction is referenced from NREL report on U.S. Department of Energy Commercial Reference Building Models of the National Building Stock. 16

17 Energy Model Input Baseline Building Thermal Performance Criteria Climate Zone Atlanta (3A) Baltimore (4A) Chicago (5A) Air Infiltration 1.57 PSF Wall R-value (R eff ) Roof R-Value (R eff ) Window U-Value Window SHGC Note: Existing pre-1980 construction is referenced from NREL report on U.S. Department of Energy Commercial Reference Building Models of the National Building Stock. 17

18 Energy Model Input Baseline Building- HVAC Systems Three Story HVAC Systems Cooling Heating Air Distribution Packaged Air Conditioning: DX Coils Furnace Single-Zone CAV Six Story Chilled water cooling Boiler Multi-Zone VAV Twelve Story Chilled water cooling Boiler Multi-Zone VAV Note: HVAC system in existing pre-1980 construction is referenced from NREL report on U.S. Department of Energy Commercial Reference Building Models of the National Building Stock. 18

19 Energy Model Input Parametric Study Energy Enhancements Considered EIFS and associated interfaces: +R7.7, Air Leakage 0.04 CFM +R15.4, Air Leakage 0.04 CFM + R23.1, Air Leakage 0.04 CFM Roof Replacement Atlanta: R24, R35, R45 Baltimore: R28.8, R41.6, R51.6 Chicago: R35, R45, R55 Window Replacement Atlanta: U=0.5, SHGC 0.25 Baltimore: U=0.42, SHGC 0.4 Chicago: U=0.42, SHGC

20 Energy Simulation Results % COST SAVING OF EIFS RETROFIT OPTIONS 14.0% % total cost saving contributed by electricity saving % total cost saving contributed by gas saving % COST SAVING 12.0% 10.0% 8.0% 6.0% 4.0% 10.2% 10.6% 9.4% 8.6% 9.0% 7.9% 6.0% 6.3% 5.5% 8.0% 8.3% 7.3% 7.6% 7.3% 8.4% 8.8% 8.0% 8.4% 2.0% 3.9% 4.2% 4.3% 0.0% 0.6% 0.6% 0.7% 0.2% 0.3% 0.4% EIFS (R12.1) EIFS (R19.8) EIFS (R27.5) EIFS (R13.3) EIFS (R21) EIFS (R28.7) EIFS (R14.1) EIFS (R21.8) EIFS (R29.5) Zone 3A Zone 4A Zone 5A THREE-STORY OFFICE BUILDING 20

21 Energy Simulation Results % COST SAVING OF EIFS RETROFIT OPTIONS 14.0% 12.0% % total cost saving contributed by electricity saving % total cost saving contributed by gas saving 11.0% 11.6% 11.9% 12.2% 13.0% 13.3% % COST SAVING 10.0% 8.0% 6.0% 4.0% 2.0% 0.0% 7.3% 8.0% 8.3% 7.5% 7.8% 7.0% 7.7% 8.0% 7.2% 6.4% 6.7% 5.9% 5.2% 5.4% 5.6% 3.8% 3.9% 3.9% 1.4% 1.5% 1.6% EIFS (R12.1) EIFS (R19.8) EIFS (R27.5) EIFS (R13.3) EIFS (R21) EIFS (R28.7) EIFS (R14.1) EIFS (R21.8) EIFS (R29.5) Zone 3A Zone 4A Zone 5A SIX-STORY OFFICE BUILDING 21

22 Energy Simulation Results % COST SAVING OF EIFS RETROFIT OPTIONS % COST SAVING 14.0% 12.0% 10.0% 8.0% 6.0% 4.0% 2.0% 0.0% -2.0% % total cost saving contributed by electricity saving % total cost saving contributed by gas saving 10.1% 7.0% 7.6% 7.9% 12.8% 13.2% 10.8% 11.1% 12.0% 9.2% 9.5% 8.5% 8.7% 9.3% 9.6% 7.1% 7.7% 8.0% 3.5% 3.6% 3.7% 1.5% 1.5% 1.5% -0.1% -0.1% -0.1% EIFS (R12.1) EIFS (R19.8) EIFS (R27.5) EIFS (R13.3) EIFS (R21) EIFS (R28.7) EIFS (R14.1) EIFS (R21.8) EIFS (R29.5) Zone 3A Zone 4A Zone 5A TWELVE-STORY OFFICE BUILDING 22

23 Energy Simulation Results % COST SAVING OF ROOF, WINDOW AND EIFS RETROFIT OPTIONS 18.0% % total cost saving contributed by electricity saving % total cost saving contributed by gas saving 17.1% % COST SAVING 16.0% 14.0% 12.0% 10.0% 8.0% 6.0% 4.0% 2.0% 0.0% 1.3% 1.5% 1.6% 1.1% 1.4% 1.5% 0.1% 0.1% 0.1% Roofing Insul (R32.7) Roofing Insul (R43.8) Roofing Insul (R53.8) 6.7% 10.4% Upgraded Window 12.8% 13.2% 12.0% 9.2% 9.5% 8.5% 3.5% 3.6% 3.7% EIFS (R14.1) EIFS (R21.8) EIFS (R29.5) ROOF WINDOW EIFS TWELVE-STORY OFFICE BUILDING - CHICAGO 23

24 Energy Simulation Results $300,000 $ Cost per % savings Twelve Story Office - Chicago $250,000 $200,000 $150,000 $100,000 $50,000 $0 Roof Window EIFS 24

25 Conclusions Roof % energy savings from roof retrofits minimal for taller buildings Windows Significant impact on total energy use, up to 17% savings Significant influence on cooling energy use Costly and disruptive to retrofit windows Pre-fabricated EIFS Panel retrofit Can provide significant % energy cost savings, up to 13% Primary influence on heating energy use Retrofit from exterior, less disruptive than window retrofit Can allow for aesthetic updates to building Best ROI of retrofit options considered Results may vary dependent on base building Retrofit decisions should be project and client specific 25

26 Thank You Thank You Chris Norris, P.E., LEED AP Principal Walter P Moore cnorris@walterpmoore.com 26