RECOMMENDATIONS FOR 15% ABOVE-CODE ENERGY EFFICIENCY MEASURES FOR COMMERCIAL OFFICE BUILDINGS

Transcription

1 ESL-TR RECOMMENDATIONS FOR 15% ABOVE-CODE ENERGY EFFICIENCY MEASURES FOR COMMERCIAL OFFICE BUILDINGS A Project for Texas Senate Bill 5 Legislation For Reducing Pollution in Nonattainment and Affected Areas Soolyeon Cho Jaya Mukhopadhyay Zi Liu, Ph.D. Charles Culp, Ph.D., P.E. Jeff Haberl, Ph.D., P.E. Bahman Yazdani, P.E. Cynthia Montgomery November 27 (Revised ) ENERGY SYSTEMS LABORATORY Texas Engineering Experiment Station Texas A&M University System

2 2 Executive Summary This report presents detailed information about the recommendations for achieving 15% above-code energy performance for commercial office buildings complying with ASHRAE Standard To accomplish the 15% annual energy consumption reductions, ten measures were considered. After energy savings were determined for each measure, they were then placed in several groups to accomplish a minimum of 15% total annual energy consumption reduction. The analysis in this paper uses the total annual energy consumption of a simulated commercial building to determine the 15% above-code recommendations. The analysis also reports end-use energy use, including: heating, cooling, domestic hot water use, fans, heat rejection, equipment and lighting loads, and miscellaneous loads as defined by the BEPS and BEPU reports from the DOE-2 program. Since the 15% abovecode savings use annual energy cost savings, these same measures will report greater savings when compared against total heating and cooling loads, which has been used in other above-code program recommendations. 1 The analysis was conducted using OFFICE.inp version 1.66.

3 3 TABLE OF CONTENTS Table of Contents... 3 List of Tables... 4 List of Figures Base Case Building Description Building Envelope, Lighting and Fenestration Characteristics HVAC System Characteristics Plant Characteristics Efficiency Measures (EEMs) Simulation Input Simulation Results Base Case Use from Various EEMs Cost Effectiveness of Various EEMs % Above-Code Description of Efficiency Measures (EEMs) Efficiency Measure 1: Improved Glazing U-value (1.22 vs..45) Efficiency Measure 2: -Efficient Lighting (Decreasing Lighting Power Density from 1.3 W/ft 2 to 1. W/ft Efficiency Measure 3: Installation of Occupancy Sensors for Lighting Efficiency Measure 4: Windows Shading (No Overhangs vs. 2.5-foot Width of Overhangs) Efficiency Measure 5: Cold Deck Reset (Constant vs. Variable) Efficiency Measure 6: Supply Fan Total Pressure (2.5 W.G. to 1.5 W.G.) Efficiency Measure 7: Chiller COP (COP 4.9 to COP 6.1) Efficiency Measure 8: Boiler Efficiency (75% to 95%) Efficiency Measure 9: VSD on Chilled Water Pump Efficiency Measure 1: VSD on Hot Water Pump References Appendix A... 48

4 4 LIST OF TABLES Table 1: Base Case Building Description... 8 Table 2: Efficiency Measures... 9 Table 3: Specifications for an Electric/Gas Building Table 4: Specifications for an All-Electric Building Table 5: Summary of Annual Use, Costs,, Implementation Costs, and Payback Periods for Houston, Texas (All-Electric) Table 6: Summary of Annual Use, Costs,, Implementation Costs, and Payback Periods for Houston, Texas (All-Electric) Table 7: Cost Information of Glazing U-value (26 RSMeans) Table 8: Cost Information of Glazing U-value (Development of the Advanced Design Guide for Small Office Buildings) Table 9: Cost Information and Payback Calculation for the Improved Glazing U-value Table 1: Comparison between Base Case and Improved Model Lighting Table 11: Cost Information of Base Case and -efficient Lighting Products Table 12: Details of Spaces and Occupancy Sensors Installed for a Typical Floor Table 13: Cost Information of Windows Overhangs Table 14: Screw Chiller Equipment and Installation Cost Information Table 15: Boiler Equipment and Installation Cost Information... 4 Table 16: Variable Speed Chilled Water Pump Equipment and Installation Cost Information Table 17: Variable Speed Chilled Water Pump Equipment and Installation Cost Information and Payback Calculation... 46

5 5 LIST OF FIGURES Figure 1: Base Case Lighting Profile for a Large Commercial Building (Source: Abushakra et al., 21) Figure 2: Use for Individual Efficiency Measures (Electric/Gas) for Houston, Texas Figure 3: Use for Individual Efficiency Measures (All-Electric) for Houston, Texas Figure 4: Increased First Costs and for the Selected Measures (Electric/Gas) Figure 5: Increased First Costs and for the Selected Measures (All-Electric) Figure 6: Payback Periods for the Selected Measures (Electric/Gas) Figure 7: Payback Periods for the Selected Measures (All-Electric) Figure 8: Use Comparison for Electric/Natural Gas Base Case (Glazing U-value, U = 1.22) and EEM (Glazing U-value, U =.45) Figure 9: Use Comparison for All-electric Base Case (Glazing U-value, U = 1.22) and EEM (Glazing U- value, U =.45) Figure 1: Data Base of Fenestration Options. ( p.e-1) Figure 11: Base Case Lighting Profile for a Large Commercial Building (Source: Abushakra et al., 21) Figure 12: Use Comparison for Electric/Natural Gas Base Case (Lighting Power Density = 1.3W/ft 2 ) and EEM (Lighting Power Density = 1.W/ft 2 ) Figure 13: Use Comparison for All-electric Base Case (Lighting Power Density = 1.3W/ft 2 ) and EEM (Lighting Power Density = 1.W/ft 2 ) Figure 14: Base Case Lighting Profile Figure 15: Modified Lighting Profile Figure 16: Use Comparison for Electric/Natural Gas Base Case (Without Occupancy Sensors) and EEM (Installing Occupancy Sensors) Figure 17: Use Comparison for All-electric Base Case (Without Occupancy Sensors) and EEM (Installing Occupancy Sensors) Figure 18: Layout of Spaces for Determining Position and Number of Occupancy Sensors Figure 19: Use Comparison for Electric/Natural Gas Base Case (No Overhangs) and EEM (2.5-foot Width of Overhangs) Figure 2: Use Comparison for All-electric Base Case (No Overhangs) and EEM (2.5-foot Width of Overhangs) Figure 21: Cold Deck Temperature Schedule Figure 22: Use Comparison for Electric/Natural Gas Base Case (Cold Deck Temperature Control: Constant) and EEM (Cold Deck Temperature Control: 6, 55, 55, and 85 F) Figure 23: Use Comparison for All-electric Base Case (Cold Deck Temperature Control: Constant) and EEM (Cold Deck Temperature Control: 6, 55, 55, and 85 F) Figure 24: Use Comparison for Electric/Natural Gas Base Case (Supply Fan Total Pressure 2.5 in. WG) and EEM (Supply Fan Total Pressure 1.5 in. WG) Figure 25: Use Comparison for All-electric Base Case (Supply Fan Total Pressure 2.5 in. WG) and EEM (Supply Fan Total Pressure 1.5 in. WG) Figure 26: Use Comparison for Electric/Natural Gas Base Case (Chiller COP 4.9) and EEM (Chiller COP 6.1)

6 6 Figure 27: Use Comparison for All-electric Base Case (Chiller COP 4.9) and EEM (Chiller COP 6.1) Figure 28: Use Comparison for Electric/Natural Gas Base Case (Boiler: Conventional, Efficiency 75%) and EEM (Boiler: Condensing, Efficiency 95%) Figure 29: Use Comparison for Electric/Natural Gas Base Case (Constant Speed Drive on CHW pump) and EEM (VSD on CHW Pump) Figure 3: Use Comparison for All-electric Base Case (Constant Speed Drive on CHW pump) and EEM (VSD on CHW Pump) Figure 31: Use Comparison for Electric/Natural Gas Base Case (Constant Speed Drive on HW pump) and EEM (VSD on HW Pump) Figure 32: Use Comparison for All-electric Base Case (Constant Speed Drive on HW pump) and EEM (VSD on HW Pump)

7 7 1. Base Case Building Description The base-case building simulation model in this analysis is based on specifications in ASHRAE Table 1 summarizes the base-case building characteristics used in the DOE-2 simulation model. The simulation used the DOE-2 program and the TMY2 hourly weather data for Houston. Electricity costs were $.119/kWh, demand charges were $5./kW, and costs for natural gas were $8./MCF Building Envelope, Lighting and Fenestration Characteristics The analysis was performed for a 6-story office building (89,34 ft 2 ), with a 5% window-to-wall ratio that follows the prescriptive tables in ASHRAE Four perimeter zones and a central core zone were modeled for each floor. Based on climate specific characteristics, the base case was modeled with a wall insulation of R-13 value and a roof insulation of R-15. The U-value of the windows in the base-case building was set at 1.22 Btu/hr ºF ft 2. 2 As per ASHRAE , the SHGC of the base-case building set at.44 for the north orientation and.17 for the other orientations 3. Window overhangs or shading were not used. The base-case building was modeled with a lighting power density (LPD) of 1.3 W/ft 2, which is the maximum value for office applications, allowed by ASHRAE The electric lighting profile was set to the recommended profile from ASHRAE s Diversity Factor Toolkit (RP-193), as shown in Figure 1 (Abushakra et al. 21). 1.8 Week day Week end Lighting Profile Hours Figure 1: Base Case Lighting Profile for a Large Commercial Building (Source: Abushakra et al., 21) HVAC System Characteristics The base-case building model used a variable air volume (VAV) system with terminal reheat that was set to have a total supply air static pressure of 2.5 inches of water (gauge), and has a constant supply air temperature of 55 ºF Plant Characteristics The base-case building has one 16 ton (1.926 MBtu/hr) screw chiller 5 with a COP of 4.9, and a constant speed chilled water pump. Two options for the heating fuel type were considered: a) natural gas (natural gas hot water boiler for space heating, and natural gas water heater for service water heating) and b) electricity (electric resistance hot water boiler for space heating, and electric water heater for service water heating). In the other sections of this report, these buildings will be referred to as (a) electric/gas building and (b) all-electric building, respectively. For the electric/gas building, heating is provided by two 731 kbtu/hr hot water gas boilers 6 with an efficiency of 75%. For the all-electric building, heating was provided by an electric resistance boiler with an efficiency of 1%. 2 ASHRAE Standard , Table B-5(Climate zone for Houston), p ASHRAE Standard , Table B-5(Climate zone for Houston), p ASHRAE Standard , Table , p As required by ASHRAE , Table 6.2.1C, p. 29, for chiller sizes between 1 tons and 3 tons. 6 As required by ASHRAE , Table 6.2.1F, p. 31.

8 8 Table 1: Base Case Building Description CHARACTERISTIC BASECASE ASSUMPTIONS SOURCES Building Building type Office Gross area (sq. ft.) 89,34 Dimension (ft. x ft.) 122 x 122 Number of floors 6 Prototypical office building size and number of floors (Huang & Franconi, 1999, p.31) Floor to floor height (ft.) 13 ASHRAE (p.15) Construction Roof absorptance.7 ASHRAE (b) (p.58) Roof insulation R-value (hr-sq. ft.- F/Btu) 15 ASHRAE , Table B-5 (11.4.2(a)), (p.95) Wall absorptance.7 ASHRAE (p.16) Wall insulation R-value (hr-sq. ft.- F/Btu) 13 ASHRAE , Table B-5 (11.4.2(a)), (p.95) Ground reflectance.2 ASHRAE (p.16) U-Factor of glazing (Btu/hr-sq. ft.- F) 1.22 ASHRAE , Table B-5 (11.4.2(c)), (p.95) Solar Heat Gain Coefficient (SHGC).17 ASHRAE , Table B-5 (11.4.2(c)), (p.95) Window-to-wall ratio 5 Average WWR of new construction (Huang & Franconi, 1999, p.31 1 ) Space Area per person (ft 2 /person) for office 275 (325 occupants) ASHRAE , Table 13-2, (p.13) Occupancy schedule 8am-1pm (Monday - Saturday) ASHRAE , Table 13-3, (p.14) Space temperature setpoint 7 F Heating / 75 F Cooling ASHRAE (p.11) Lighting load (W/ft2) for Office 1.3 ASHRAE , Table , (p.51) Lighting schedule 24 hours (Monday - Saturday) Abushakra et al., 21, (ASHRAE RP-193, p.61) Equipment load (W/ft2) for office.75 ASHRAE , Table 13-4, (p.16) Equipment schedule 24 hours (Monday - Saturday) Abushakra et al., 21, (ASHRAE RP-193, p.62) HVAC Systems HVAC system type VAV with terminal reheat ASHRAE , Table A, (p.59, System2) Number of HVAC units 5 Serving 5 thermal zones Supply motor efficiency 9 Kavanaugh, 23 (p.38) Supply fan efficiency 61 ASHRAE , Table 13-6, (p.18, System #5) Supply fan total pressure (in W.G) 2.5 Info. by ESL CC engineers Plant Equipment Chiller type Screw ASHRAE , Table 6.2.1C, (p.29) Chiller COP 4.9 ASHRAE , Table 6.2.1C, (p.29) Boiler type Hot water boiler Electric resistance boiler ASHRAE , Table A, (p.59, System2) Boiler fuel type Natural gas Electricity ASHRAE , Table A, (p.59, System2) Boiler thermal efficiency 75 1 ASHRAE , Table 6.2.1F, (p.31) DHW fuel type Natural gas ASHRAE , Table 7.2.2, (p.47) DHW heater thermal efficiency 8 ASHRAE , Table 7.2.2, (p.47)

9 9 2. Efficiency Measures (EEMs) A total of 1 measures were considered to achieve a 15% annual energy consumption reduction when compared to code (ASHRAE 9.1, 1999) for the electric/gas and the all-electric buildings. These measures included improved glazing U-value, decreasing lighting power density, window shading, reducing static pressure, improving chiller COP, improving boiler efficiency, cold deck reset, VSDs on chilled and hot water pumps, and occupancy sensors for lighting control. After costs were determined for each measure, they were then placed in several groups to accomplish a minimum of 15% total annual energy consumption reduction. A list of all measures is provided in Table 2. Table 2: Efficiency Measures NATURAL GAS HEATING/NATURAL GAS DHW SYSTEM ELECTRIC RESISTANCE HEATING / ELECTRIC DHW SYSTEM A 1 Envelope and Fenestration Measures Improved Window Performance (U-factor =.45 Btu/hr-sqft C) Improved Window Performance (U-factor =.45 Btu/hr-sqft C) 2 Improved lighting load (1W/sqft) 3 Occupancy sensors for lights 4 B 5 6 C 7 Shading (ft) (From ft to 2.5 ft) HVAC System Measures Cold deck reset (Constant to variable) Supply fan total pressure (From 2.5 inw.g. to 1.5 inw.g.) Plant Equipment Measures Chiller COP (from 4.9 to 6.1) Improved lighting load (1W/sqft) Occupancy sensors for lights (Using occupancy schedules) Shading (ft) (From ft to 2.5 ft) Cold deck reset (From 55F to 6:55F; 55:85F) Supply fan total pressure (From 2.5 inw.g. to 1.5 inw.g.) Chiller COP (from 4.9 to 6.1) 8 Boiler efficiency (75% to 9%) NA 9 VSD on chilled water loop VSD on chilled water loop 1 VSD on hot water loop VSD on hot water loop

10 1 3. Simulation Input Table 3 and Table 4 list the inputs for simulating the measures in a representative office building located in Houston, Texas for an electric/gas building (Table 3) and an all-electric building (Table 4). Both systems had an electric chiller with a VAV air-handling unit. The values used for base case are presented in the first row of each of the tables. The subsequent rows present information used in each of the individual energy efficiency measures. The shaded boxes in each row indicate changes in input values of the measures being simulated. 4. Simulation Results Table 5 and Table 6 summarize the annual energy use, energy costs 7, savings (both energy and dollars), implementation costs, and the calculated simple payback periods for the energy efficiency measures simulated for both the electric/gas building (Table 5), and the all-electric building (Table 6), for a building in Houston, Texas. In order to calculate the 15% above-code annual energy cost savings, the simulated electric and/or natural gas use was converted into total annual energy costs 8. Figure 2 through Figure 7 graphically present the results of the simulations and cost analysis. Figure 2 and Figure 3 present the impact of energy efficiency measures on different energy uses; Figure 4 and Figure 5 present the first cost and the energy cost savings for different measures; Figure 6 and Figure 7 show the corresponding payback period in years Base Case Use The total annual energy consumption for the base-case building in Houston, Texas, was 5,658 MMBtu for the electric/gas building, and 5,554 MMBtu for the all-electric building. 7 The energy use shown was obtained from DOE-2 s BEPS and BEPU report. 8 This is required when simulating a code-compliant building that follows ASHRAE Standard For this analysis costs of $.119/kWh, $5/kW and $.8/therms were used.

11 11 Table 3: Specifications for an Electric/Gas Building. EEM # Efficiency Measures Glazing U- Lighting Load factor (Btu/hrsqft-F) (W/sqft) Occupancy Sensors for Lights Shading (ft) Cold Deck Reset (F) Supply Fan Total Pressure (in W.G.) Chiller COP Boiler Efficiency VSD on Chilled Water Loop VSD on Hot Water Loop BaseCase None None Efficiency Constant Speed Lighting Schedule Envelope and fenestration measures 1 Glazing U-factor (Btu/hr-sqft-F) None None Constant Speed Constant Speed 2 Lighting Load (W/sqft) None None Constant Speed Constant Speed 3 Occupancy Sensors for Lights Lit. Sch. = Occ. Sch. None Constant Speed Constant Speed 4 Shading (ft) None Constant Speed Constant Speed HVAC System Measures 5 Cold Deck Reset (F) None None (6:55,55:85) Constant Speed Constant Speed 6 Supply Fan Total Pressure (in W.G.) None None Constant Speed Constant Speed Plant Equipment Measures 7 Chiller COP None None Constant Speed Constant Speed 8 Boiler Efficiency None None Constant Speed Constant Speed 9 VSD on Chilled Water Loop None None Variable Speed Constant Speed 1 VSD on Hot Water Loop None None Constant Speed Variable Speed Table 4: Specifications for an All-Electric Building. Glazing U- Occupancy EEM Lighting Load Cold Deck Reset Supply Fan Total VSD on Chilled Water VSD on Hot Water Efficiency Measures factor (Btu/hrsqft-F) Lights Sensors for Shading (ft) Chiller COP Boiler Efficiency # (W/sqft) (F) Pressure (in W.G.) Loop Loop BaseCase None None Constant Speed Lighting Schedule Envelope and fenestration measures 1 Glazing U-factor (Btu/hr-sqft-F) None None Constant Speed Constant Speed 2 Lighting Load (W/sqft) None None Constant Speed Constant Speed 3 Occupancy Sensors for Lights Lit. Sch. = Occ. Sch. None Constant Speed Constant Speed 4 Shading (ft) None Constant Speed Constant Speed HVAC System Measures 5 Cold Deck Reset (F) None None (6:55,55:85) Constant Speed Constant Speed 6 Supply Fan Total Pressure (in W.G.) None None Constant Speed Constant Speed Plant Equipment Measures 7 Chiller COP None None Constant Speed Constant Speed 8 Boiler Efficiency None None Constant Speed Constant Speed 9 VSD on Chilled Water Loop None None Variable Speed Constant Speed 1 VSD on Hot Water Loop None None Constant Speed Variable Speed

12 12 6, 5, 4, MBtu/yr 3, 2, 1, New Baseline (L&E Schedule from RP-193) Glazing U-factor (Btu/hrsqft-F) Lighting Load (W/sqft) Occupancy Sensors for Lights Shading (ft) Cold Deck Reset (F) Supply Fan Total Pressure (in W.G.) Chiller COP Boiler Efficiency VSD on Chilled Water Loop VSD on Hot Water Loop Total 5,658 5,51 5,268 4,922 5,549 5,385 5,583 5,436 5,533 5,521 5,481 DHW Fans Misc HtRj Cooling 1,126 1,125 1, ,58 1,53 1, ,126 1,61 1,126 Heating-NG Heating-Elec Equip. 1,377 1,377 1,377 1,377 1,377 1,377 1,377 1,377 1,377 1,377 1,377 Lighting 1,811 1,811 1, ,811 1,811 1,811 1,811 1,811 1,811 1,811 Figure 2: Use for Individual Efficiency Measures (Electric/Gas) for Houston, Texas. 6, 5, 4, MBtu/yr 3, 2, 1, Baseline Glazing U-factor (Btu/hrsqft-F) Lighting Lo ad (W/sqft) Occupancy Sensors for Lights Shading (ft) Cold Deck Reset (F) Supply Fan Total Pressure (in W.G.) Chiller COP Boiler Efficiency VSD on Chilled Water Loop VSD on Hot Water Loop Total 5,554 5,61 5,13 4,735 5,443 5,341 5,479 5,332 5,554 5,417 5,445 DHW Fans Misc HtRj Cooling 1,126 1,125 1, ,58 1,53 1, ,126 1,61 1,126 Heating-NG Heating-Elec Equip. 1,377 1,377 1,377 1,377 1,377 1,377 1,377 1,377 1,377 1,377 1,377 Lighting 1,811 1,811 1, ,8 11 1,8 11 1,811 1,811 1,8 11 1,8 11 1,8 11 Figure 3: Use for Individual Efficiency Measures (All-Electric) for Houston, Texas.

13 from Various EEMs For both building types, the implementation of occupancy sensors for lighting and improved glazing U-factors had the greatest individual impact on the total annual energy consumption of the building. The implementation of occupancy sensors in the electric/gas building yields an annual energy consumption savings of 736 MBtu (13%). This same measure in the all-electric building yields a savings of 819 MBtu (14.7%). Surprisingly, the implementation of shading strategies and reduction of the supply fan static pressure resulted in comparatively small annual savings. For the electric/gas building, the implementation of shading strategies yields an annual energy savings of 18 MBtu (1.9%). This same measure in the all-electric building yields a savings of 11 MBtu (2%). Table 5: Summary of Annual Use, Costs,, Implementation Costs, and Payback Periods for Houston, Texas (All-Electric). EEM # Efficiency Measures Use (MBtu/yr) Use (Utility Units) Cooling Heating DHW Other Total kwh/yr therms/yr $/yr MBtu/yr % kwh/yr therms/yr $/yr Increased First Year Cost Payback (yrs) Envelope and Fenestration Measures Basecase 1, ,899 5,658 1,472,338 6,325 $196,566 1 Glazing U Factor (1.22 to.45 Btu/hr-sf-F) 1, ,815 5,51 1,447,64 1,16 $188, % 24,698 5,219 $7,631 $95,13 - $174, Lighting Load (1.3 to 1. w/sq-ft) 1, ,46 5,268 1,325,451 7,447 $178, % 146,887-1,122 $18,277 $ - $ Occupancy Sensors Installation Shading (none to 2.5 ft overhangs) ,24 4,922 1,172,19 9,211 $163, % 3,148-2,886 $33,32 $26,5 - $28, , ,859 5,549 1,44,495 6,331 $192, % 31,843-6 $4,223 $67,9 $11, HVAC System Measures Basecase 1, ,899 5,658 1,472,338 6,325 $196,566 5 Cold Deck Reset 1, ,95 5,385 1,452,735 4,269 $192, % 19,63 2,56 $3,887 $ - $ Supply Fan Total Pressure (2.5 to 1.5 in-h2o) 1, ,841 5,583 1,45,195 6,333 $193, % 22,143-8 $2,958 $ - $ Plant Equipment Measures Basecase 1, ,899 5,658 1,472,338 6,325 $196,566 Chiller COP (4.9 to ,899 5,436 1,47,487 6,325 $187, % 64,851 $8,718 $16, - $18, ) 8 Boiler Efficiency 1, ,899 5,533 1,472,338 5,84 $195, % -64,851 1,241 $993 $25, - $35, VSD on Chilled Water Pump (from Constant to VSD) 1, ,828 5,521 1,432,31 6,325 $191, % 4,37 $4,885 $3,7 - $4, VSD on Hot Water Pump (from Constant to VSD) 1, ,868 5,481 1,463,265 4,871 $194, % 9,73 1,454 $2,36 $4, - $5, Table 6: Summary of Annual Use, Costs,, Implementation Costs, and Payback Periods for Houston, Texas (All-Electric). EEM # Cooling Heating DHW Other Total kwh/yr therms /yr $/yr MBtu/yr % kwh/yr Envelope and Fenestration Measures Basecase 1, ,879 5,554 1,627,216 $214,554 1 Glazing U Factor (1.22 to.45 Btu/hrsf-F) 1, ,812 5,61 1,482,815 $192, % 144,41 $21,91 $95,13 - $174, Lighting Load (1.3 to 1. w/sq-ft) 1, ,436 5,13 1,53,67 $199, % 124,149 $15,317 $ - $ Occupancy Sensors Installation ,995 4,735 1,387,338 $187, % 239,878 $27,78 $26,5 $ $28, Shading (none to 2.5 ft overhangs) 1, ,838 5,443 1,594,868 $21, % 32,348 $4,321 $67,9 $11, HVAC System Measures Basecase 1, ,879 5,554 1,627,216 $214,554 5 Cold Deck Reset 1, ,252 5,341 1,564,931 $25, % 62,285 $8,656 $ - $ Supply Fan Total Pressure (2.5 to 1.5 in-h2o) 1, ,334 5,479 1,65,23 $211, % 21,986 $2,916 $ - $ Plant Equipment Measures Basecase 1, ,879 5,554 1,627,216 $214,554 7 Chiller COP (4.9 to 6.1) ,392 5,332 1,562,366 $26, % 64,85 $8,482 $16, - $18, Boiler Efficiency (Not Aplicable) 1, ,372 5,533 1,627,216 $214,554.% $ NA - NA Efficiency Measures VSD on Chilled Water Pump (from Constant to VSD) Use (MBtu/yr) Use (Utility Units) 1, ,32 5,417 1,587,179 $29, % 4,37 $4,972 $3,7 - $4, therms /yr $/yr Increased First Year Cost Payback (yrs) 1 VSD on Hot Water Pump (from Constant to VSD) 1, ,283 5,445 1,595,389 $21, % 31,827 $3,96 $4, - $5,

14 Cost Effectiveness of Various EEMs Figure 4 (electric/gas) and Figure 5 (all-electric) show the increased costs and annual energy cost savings from the energy-efficiency measures for lowered energy consumption for the different measures adopted. For example, in an electric/gas building with an improved glazing U-factor, the estimated first costs increased by $134,64 and saved $7,631, which represents a payback period of 12 years. In contrast, installing occupancy sensors cost $27,25, which saved $33,31, for a simple payback of less than one year. For both system types, four measures had very favorable paybacks of less than four years. These include occupancy sensors, improved chiller COP, and VSDs on the hot and chilled water pumps. Figure 6 (electric/gas) and Figure 7 (all-electric) present the payback period in years for each of the measures implemented. Shading strategies did not perform well for both building types. The average first costs of installing shading strategies were $88, for both building types. However, the energy savings obtained from implementing these strategies was $4,233 for the electric/gas building and $4,321 for the all-electric building. The resulting average payback periods were 21 years for both building types % Above-Code Figures 8 and 9 present the 15% above-code savings charts for an electric/gas building (Figure 8) and an all-electric building (Figure 9). These charts represent the final summary presentation of the detailed information previously shown in Tables 1 to 5 and Figures 4 to 7. In Figures 8 and 9 the results are presented for Houston, Texas, which are also applicable for Brazoria, Fort Bend, Galveston, Harris, Montgomery, and Waller counties. Similar results for other non-attainment 9 counties in Texas can be found in the attachment of this report or the Laboratory s Senate Bill 5 website (eslsb5.tamu.edu). In these figures, the upper table summarizes the results for individual measures in terms of annual energy savings (percent and dollars/year), annual demand savings (percent and dollars/year), combined savings (energy and demand in dollars/year), and the estimated costs for each measure 1. The second table in each figure summarizes the results obtained by implementing combinations of measures. Results are presented in terms of combined energy savings (percent and dollars/year), combined demand savings (percent and dollars/year), combined savings (energy plus demand in dollars/year), combined implementation costs (marginal and new system costs) and simple payback periods (years). NOx emissions reductions for each of the combinations are also presented in terms of annual NOx emission savings (lbs/year) and savings during the ozone season period (OSP) 11 (lbs/day). The maps of all the nonattainment and near non-attainment counties and specific counties for each page are included in the upper and lower figures. For the case of an electric/gas building, combining the measures of a glazing U-value of.45 Btu/hr-ft 2 - F and a lighting load of 1 W/ft 2 in combination 1 yields a combined energy savings of 2%. Combining the measures of installing occupancy sensors and a cold deck reset in combination 2 yields a combined energy savings of 19.6%. Combination 3 consists of implementing a low glazing U-value of.45 Btu/hr-ft 2 - F, a chiller COP of 6.1, a boiler efficiency of 95%, and a VSD on the chilled water pump which yields a combined energy savings of 16.8%. For the case of an all-electric building, combining the measures of a glazing U-value of.45 Btu/hr-ft 2 - F and a lighting load of 1 W/ft 2 in combination 1 yields a combined energy savings of 18.5%. Combining the measures of installing occupancy sensors and a cold deck reset in combination 2 yields a combined energy savings of 19.8%. Combination 3 consists of implementing a low glazing U-value of.45 Btu/hr-ft 2 - F, a chiller COP of 6.1, and VSDs on the chilled water pump and hot water pump which yields a combined energy savings of 15.5%. 9 The Clean Air Act and Amendments of 199 define a nonattainment area as a locality where air pollution levels persistently exceed National Ambient Air Quality Standards, or that contributes to ambient air quality in a nearby area that fails to meet standards. ( 1 The costs for measures are presented as marginal costs and new systems costs, where marginal costs represent the incremental costs to implement the measure by modifying an existing system. New system costs represent costs for newly installed measures. 11 The Ozone Season Period (OSP) represents average daily savings during the hottest period of the year from mid-july to mid-september as defined by the U.S.E.P.A.

15 15 Increased Ist Costs in Dollars $2, $16, $12, $8, $4, $ Glazing U Factor (1.22 to.45 Btu/hr-sf-F) Lighting Load (1.3 to 1. w/sq-ft) Occupancy Sensors Installation Shading (none to 2.5 ft overhangs) Cold Deck Reset Supply Fan Total Pressure (2.5 to 1.5 in-h2o) Chiller COP (4.9 to 6.1) Boiler Efficiency (Not Aplicable) VSD on Chilled Water Pump (from Constant to VSD) VSD on Hot Water Pump (from Constant to VSD) Min 1st costs $95,13 $ $26,5 $67,9 $ $ $16, $25, $3,7 $4, Max 1st costs $174,15 $ $28, $11, $8 $2 $18, $35, $4,7 $5, Av. 1st costs $134,64 $ $27,25 $88,95 $4 $1 $17, $3, $4,2 $4,5 $7,631 $18,277 $33,32 $4,223 $3,887 $2,958 $8,718 $993 $4,885 $2,36 Figure 4: Increased First Costs and for the Selected Measures (Electric/Gas). $35, $3, $25, $2, $15, $1, $5, $ in Dollars Increased Ist Costs in Dollars $2, $16, $12, $8, $4, $ Glazing U Factor (1.22 to.45 Btu/hr-sf-F) Lighting Load (1.3 to 1. w/sq-ft) Occupancy Sensors Installation Shading (none to 2.5 ft overhangs) Cold Deck Reset Supply Fan Total Pressure (2.5 to 1.5 in-h2o) Chiller COP (4.9 to 6.1) Boiler Efficiency (Not Aplicable) VSD on Chilled Water Pump (from Constant to VSD) VSD on Hot Water Pump (from Constant to VSD) $35, $3, $25, $2, $15, $1, $5, $ in Dollars Min 1st costs $95,13 $ $26,5 $67,9 $ $ $16, $ $3,7 $4, Max 1st costs $174,15 $ $28, $11, $8 $2 $18, $ $4,7 $5, Av. 1st costs $134,64 $ $27,25 $88,95 $4 $1 $17, $ $4,2 $4,5 $21,91 $15,317 $27,78 $4,321 $8,656 $2,916 $8,482 $ $4,972 $3,96 Figure 5: Increased First Costs and for the Selected Measures (All-Electric). 4. Number of Years Glazing U Factor (1.22 to.45 Btu/hr-sf- F) Lighting Load (1.3 to 1. w/sq-ft) Occupancy Sensors Installation Shading (none to 2.5 ft overhangs) Cold Deck Reset Supply Fan Total Pressure (2.5 to 1.5 in- H2O) Chiller COP (4.9 to 6.1) Boiler Efficiency VSD on Chilled Water Pump (from Constant to VSD) VSD on Hot Water Pump (from Constant to VSD) Min Years Max Years Av. Years Figure 6: Payback Periods for the Selected Measures (Electric/Gas). 4. Number of Years Glazing U Factor (1.22 to.45 Btu/hr-sf- F) Lighting Load (1.3 to 1. w/sq-ft) Occupancy Sensors Installation Shading (none to 2.5 ft overhangs) Cold Deck Reset Supply Fan Total Pressure (2.5 to 1.5 in- H2O) Chiller COP (4.9 to 6.1) Boiler Efficiency (Not Aplicable) VSD on Chilled Water Pump (from Constant to VSD) VSD on Hot Water Pump (from Constant to VSD) Min Years Max Years Av Years Figure 7: Payback Periods for the Selected Measures (All-Electric).

16 16 5. Description of Efficiency Measures (EEMs) This section includes a description of EEMs, their impact on the energy use, increased cost of implementation, and calculations for simple payback. The energy use of the base-case building with base-case characteristics and with the EEM is also plotted. This includes annual end-use energy use (MMBtu) obtained from the BEPS report and monthly electricity use (kwh), monthly electric demand (kw), and gas use (therm) obtained from PS-B report of the DOE-2 output Efficiency Measure 1: Improved Glazing U-value (1.22 vs..45) Base Case As per ASHRAE , the U-value of the windows in the base-case building was set at 1.22 Btu/hr-ft 2 - F 12. The SHGC of the base-case building was set at.44 for the north orientation and.17 for the other orientations 13. Window overhangs or shading were not used. Decreased Glazing U-value (from 1.22 to.45) To improve the glazing performance, the U-value was reduced to.45 Btu/hr-ft 2 - F 14 from 1.22 Btu/hr-ft 2 - F (ASHRAE 24). This U-value was chosen to minimize winter-time heat loss using available commercial glazing products. The SHGC of the base-case building remained at.44 for the north orientation and.17 for the other orientations 15. Figure 8 and Figure 9 compare the annual energy use of a commercial building in Houston with base-case characteristics and with this measure. Figure 8 shows that this measure applied to an electric/gas base-case building: Reduced the space cooling energy use from 1,126 MMBtu/year to 1,125 MMBtu/year. Reduced the space heating energy from 61 MMBtu/year to 71 MMBtu/year, Reduced the total energy use from 5,658 MMBtu/year to 5,51 MMBtu/year, i.e., 66.3 MMBtu/year of total energy savings, Reduced the electricity use from 1,472,338 kwh/year to 1,325,451 kwh/year, i.e., 24,698 kwh/year electricity savings, Reduced the gas use from 6,325 therms/year to 1,16 therms/year, i.e., 5,219 therms/year gas savings, and Reduced the peak demand from 3,26 kw to 3,156 kw. Figure 9 shows that this measure applied to an all-electric base-case building: Reduced the space cooling energy use from 1,126 MMBtu/year to 1,125 MMBtu/year, Reduced the space heating energy from MMBtu/year to 87.2 MMBtu/year, Reduced the total energy use from 5,554 MMBtu/year to 5,61 MMBtu/year, i.e., 493 MMBtu/year or total energy savings, Reduced the electricity use from 1,627,216 kwh/year to 1,482,815 kwh/year, i.e., 144,41 kwh/year electricity savings, and Reduced the peak demand from 4,183 kw to 3,238 kw. 12 ASHRAE Standard , Table B-5(Climate zone for Houston), p ASHRAE Standard , Table B-5(Climate zone for Houston), p From Table for Climate Zone 2 from Advanced Design Guide for Small Office Buildings. Although this guide was developed for small office buildings, i.e., up to 2, ft 2, its use in this study was deemed appropriate. 15 As required by ASHRAE , Table 5.3, p. 24. (Derived from Table B-5, p. 95.)

17 17 MBtu/yr 6, 5, 4, 3, 2, 1, Base Case U-value =.45 Total 5,658 5,51 DHW Fans Misc HtRj Cooling 1,126 1,125 Heating-NG Heating-Elec Equip. 1,377 1,377 Lighting 1,811 1,811 Use (kwh/mo) 16, 14, 12, 1, 8, 6, 4, 2, Use and Comparison (Glazing U-value: 1.22 vs..45) JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Elec. Use_U= ,47 13, , , ,45 131,79 14, ,44 125, , , ,679 Elec. Use_U= ,415 11, , ,94 127, , , , , ,14 114,4 11,862 _U= _U= Gas Use_U=1.22 1,613 1, ,433 Gas Use_U= ,4 2,1 1,8 1,5 1, (kw), Natural Gas Use (Therm/mo) Figure 8: Use Comparison for Electric/Natural Gas Base Case (Glazing U-value, U = 1.22) and EEM (Glazing U-value, U =.45). MBtu/yr 6, 5, 4, 3, 2, 1, Base Case Glazing U- value =.45 Total 5,554 5,61 DHW Fans Misc Ht. Rj Cooling 1,126 1,125 Use (kwh/mo) 16, 14, 12, 1, 8, 6, 4, 2, Use and Comparison (Glazing U-value: 1.22 vs..45) 2,4 2,1 1,8 1,5 1, (kw), Natural Gas Use (Therm/mo) Heating - Elec Equip. 1,377 1,377 Lighting 1,811 1,811 JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Elec. Use_U= , , , , ,62 136, ,79 145, , , , ,394 Elec. Use_U= ,969 14,33 119, ,75 13,732 13,65 138, , ,53 126, ,61 113,98 _U= _U= Figure 9: Use Comparison for All-electric Base Case (Glazing U-value, U = 1.22) and EEM (Glazing U- value, U =.45).

18 18 Implementation Cost Two sources, RSMeans and Advanced Design Guide (AEDG), were used to find the cost information for the improved glazing U-value. The information used in the analysis is provided in Table 9. The total additional cost for the improved U-value ranges from about $ 95,13 to $174,154. The data sources are as follows. 1) RSMeans (26) Table 7 shows the cost information from 26 RSMeans. Total increased cost for the double pane clear glass is $13,969 and for the double pane low-e coating with air is $174,154. Table 7: Cost Information of Glazing U-value (26 RSMeans). Type of Glass Thickness # Pane U-value (Btu/hrft 2 - F) Mat. Cost ($/ft 2 ) Labor Cost ($/ft 2 ) Total Unit Cost ($/ft 2 ) Increased Unit Cost ($/ft) Total Glass Area (ft2) Total Glazing Cost Total Increased Cost Code Abovecode Abovecode Clear plain Clear plain Clear with 1 low-e coating w/ air 1/4" , ,81 1/4" , ,5 13,969 1/4" ,176 29, ,154 2) Development of the Advanced Design Guide (AEDG) for Small Office Buildings ( p. E-1) This report shows the cost information for the increased glazing U-value. Figure 1 retrieved from the report shows the data of fenestration options. According to this report, the additional unit cost ($/ft 2 ) for the increased U-value is $7.22. Therefore, the total additional cost would be $95,131 for the building. Table 8: Cost Information of Glazing U-value (Development of the Advanced Design Guide for Small Office Buildings). U-value (Btu/hr- ft 2 - F) Additional Cost ($/ft 2 ) Total Glass Area (ft 2 ) Total Increase in Cost Code ,176 Above-code ,176 95,131 Table 9: Cost Information and Payback Calculation for the Improved Glazing U-value. Base Case EEM Fenestration Measure Clear single pane windows: U = 1.22 Increased U-value: U =.45 Total Glass Area Increased Unit Cost Total Increase Cost Referemce (ft 2 ) ($/ft 2 ) 13,176 13,176 $ $13.22 $ 95,13 - $174,154

19 19 Figure 1: Data Base of Fenestration Options. ( p. E-1) Payback Calculation (a) For Electric/gas building: Electricity cost savings = 24,698 kwh x $.119/kWh = $ Gas cost savings = 5,219 therm x.1 (MCF/therm) x $8/MCF = $ savings = kw x $5./kW = $ Total savings = $ Cost difference = $ 95,13 ~ $174,154 Simple Payback = to years (b) For All-Electric building: Electricity cost savings = kwh x $.119/kWh = $ 17, savings = kw x $5./kW = $ 4726 Total savings = $ 2191 Cost difference = $ 95,13 ~ $174,154 Simple Payback = 4.3 to 7.9 years

20 Efficiency Measure 2: -Efficient Lighting (Decreasing Lighting Power Density from 1.3 W/ft 2 to 1. W/ft 2 Base Case The base-case building was modeled with a lighting power density (LPD) of 1.3 W/ft 2, which is the maximum value for office applications allowed by ASHRAE The electric lighting profile was set to the recommended profile from ASHRAE s Diversity Factor Toolkit (RP-193), as shown in Figure 11 (Abushakra et al. 21). 1.8 Week day Week end Lighting Profile Hours Figure 11: Base Case Lighting Profile for a Large Commercial Building (Source: Abushakra et al., 21). Improved Model with -Efficient Lighting The impact of energy-efficient lighting was determined by reducing the Lighting Power Density (LPD) from 1.3 W/ft 2 to 1. W/ft There are a number of lighting systems available to meet the LPD requirements, including fixture type, fixture size, type of lens or louver, and mounting height. However, only the lamp type and ballast type were considered in this cost analysis. Figure 12 and Figure 13 compare the annual energy use of a commercial building in Houston with base-case characteristics and with this measure. Figure 12 shows that this measure applied to an electric/gas base-case building: Reduced the space cooling energy use from 1,126 MMBtu/year to 1,63.5 MMBtu/year, Increased the space heating energy from 61 MMBtu/year to 726 MMBtu/year, Reduced the total energy use from 5,658 MMBtu/year to 5,268 MMBtu/year, i.e., 389 MMBtu/year of total energy savings, Reduced the electricity use from kwh/year to kwh/year, i.e., kwh/year electricity savings, Increased the gas use from 6,325 therms/year to 7447 therms/year, i.e., 1122 therms/year increase in gas use, and Reduced the peak demand for July from 326 kw to 2921 kw. Figure 13 shows that this measure applied to an all-electric base-case building: Reduced the space cooling energy use from 1,126 MMBtu/year to 1,63.5 MMBtu/year, Increased the space heating energy from MMBtu/year to 594MMBtu/year, Reduced the total energy use from 5,554 MMBtu/year to 5,13 MMBtu/year, i.e., 424 MMBtu/year or total energy savings, Reduced the electricity use from 1,627,216 kwh/year to 1,53,67 kwh/year, i.e., 124,149 kwh/year electricity savings, and Reduced the peak demand from 4,183 kw to 4,74 kw. 16 ASHRAE Standard , Table , p This is the recommended level in ASHRAE for general office space.

21 21 6, 5, Use and Comparison (Lighting Power Density: 1.3 W/sq-ft vs. 1. W/sq-ft) MBtu/yr 4, 3, 2, 1, Base Case LPD = 1W/sqft Total 5,658 5,268 DHW Fans Misc HtRj Use (kwh/mo) 16, 14, 12, 1, 8, 6, 2,4 2,1 1,8 1,5 1,2 9 (kw), Natural Gas use (Therm/mo) Cooling 1,126 1,64 4, 6 Heating-NG Heating-Elec , 3 Equip. 1,377 1,377 Lighting 1,811 1,393 JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Elec. Use_With 1.3 W/sq. ft. 116,47 13, , , ,45 131,79 14, ,44 125, , , ,679 Elec. Use_With 1. W/sq. ft. 15,331 94,127 15,657 14, , , , , ,812 11,996 12,828 12,972 _With 1.3 W/sq. ft _With 1. W/sq. ft Gas Use_With 1.3 W/sq. ft. 1,613 1, ,433 Gas Use_With 1. W/sq. ft. 1,881 1, ,753 Figure 12: Use Comparison for Electric/Natural Gas Base Case (Lighting Power Density = 1.3W/ft 2 ) and EEM (Lighting Power Density = 1.W/ft 2 ). 6, 5, Use and Comparison (Lighting Power Density: 1.3 W/sq-ft vs. 1. W/sq-ft) 4, 16, 2,4 MBtu/yr 3, 2, 1, Base Case LPD = 1W/sqft Total 5,554 5,13 DHW Fans Misc Use (kwh/mo) 14, 12, 1, 8, 6, 4, 2,1 1,8 1,5 1,2 9 6 (kw), Natural Gas use (Therm/mo) Ht. Rj , 3 Cooling 1,126 1,64 Heating JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Equip. 1,377 1,377 Elec. Use_With 1.3 W/sq. ft. 15, , , , ,62 136, ,79 145, , , , ,394 Lighting 1,811 1,393 Elec. Use_With 1. W/sq. ft. 144, , ,81 11, , , , , ,72 117,21 112, ,83 _With 1.3 W/sq. ft _With 1. W/sq. ft Figure 13: Use Comparison for All-electric Base Case (Lighting Power Density = 1.3W/ft 2 ) and EEM (Lighting Power Density = 1.W/ft 2 ).

22 22 Implementation Cost There are a number of variables that can affect the installation cost of lighting systems in order to meet the LPD requirements as described above. Some of these are fixture type, fixture size, type of lens or louver, and mounting height. The cost analysis is simplified by considering the changes in general lighting systems and whole building LPD, and assuming other costs to be the same. Table 1 shows the details of the lighting system for the two scenarios. The lighting power density of 1.3 W/ft 2 can be achieved by fixtures with 3 34 Watt T12 lamps and magnetic ballast. To achieve the LPD of 1. W/ft 2, similar fixtures with 3-32Watts T8 lamps and electronic ballast are required. It was assumed that the most common light fixtures currently used in new construction is the 2x4 recessed, lay-in luminaire that would accommodate both lamp types. This fixture would also contain painted white reflecting surfaces and an acrylic, prismatic lens, and satisfy the maximum allowed power density while providing 3-5 footcandles on the work plane, depending on mounting height and/or room configuration. Finally, the cost of lighting is obtained from online sources. Table 11 shows the cost of both base-case and energy-efficient lighting products. Assuming that the other costs (including fixture cost, labor cost, and cost of wiring and accessories) are the same, there is no increased cost estimate compared to the base case. Table 1: Comparison between Base Case and Improved Model Lighting. Fixture Lamp Ballast Watt/lamp Watt/Fixture Basecase -efficient Lighting F43EE (3-48, 34W, T-12 Lamps Fixture) F43ILL (3-48, 32W, T-8 Lamps Fixture) F34T12 Magnetic-ES 34W 115W F32T8 Instant Star Electronic 32W 85W Table 11: Cost Information of Base Case and -efficient Lighting Products. Lamp Brand Cost/unit 18 Ballast Brand Cost/unit 19 Basecase F34T12 Fluorescent Bulb Philips $1.19-$ Volt One or Two Lamp F34T12 Magnetic Ballast Advance Transformer $11.99-$ efficient Lighting F32T8 Fluorescent Bulb GE $1.29-$ Volt Three Lamp F32T8 Electronic Ballast Advance Transformer $16.99-$24.99 Payback Calculation (a) For Electric/gas building: Electricity cost savings = kwh x $.119/kWh = $ 1748 Gas cost savings = therm x.11 (MCF/therm) x $8/MCF = - $ 987 savings = 339 kw x $5./kW = $ 1695 Total savings = $ Cost difference = None Simple Payback = Immediate savings (b) For All-Electric building: Electricity cost savings = kwh x $.119/kWh = $ savings = 18.7 kw x $5./kW = $ 543 Total savings = $ 15,317 Cost difference = None Simple Payback = Immediate savings

23 Efficiency Measure 3: Installation of Occupancy Sensors for Lighting Base Case The base-case building is modeled with a lighting power density of 1.3 W/sq. ft., as required by ASHRAE (Table , p. 51). The electric lighting profile is adopted from RP-193 Report (Large Buildings) and is shown in Figure 14. Improved Model with Occupancy Sensors for Lighting The energy impact from the installation of occupancy sensors for lighting is determined by specifying that the electric lighting profile is the same as the occupancy profile (Figure 15), which is adopted from ASHRAE (Table 13-3, p.14). Lighting Profile Weekday Weekend Saturday Hours Modified Lighting Profile Weekday Weekend Saturday Hours Figure 14: Base Case Lighting Profile. Figure 15: Modified Lighting Profile. Figure 16 and Figure 17 compare the annual energy use of a commercial building in Houston with base-case characteristics and with this measure. Figure 16 shows that this measure applied to an electric/gas base-case building: Reduced the space cooling energy use from 1,126 MMBtu/year to 976 MMBtu/year, Increased the space heating energy from 61 MMBtu/year to 97.4 MMBtu/year, Reduced the total energy use from 5,658 MMBtu/year to 4921 MMBtu/year, i.e., MMBtu/year of total energy savings, Reduced the electricity use from kwh/year to kwh/year, i.e., 3148 kwh/year electricity savings, Increased the gas use from 6,325 therms/year to 9211 therms/year, i.e., 2886 therms/year increase in gas use, and Increased the demand from 326 kw to 3335 kw. Figure 17 shows that this measure applied to an all-electric base-case building: Reduced the space cooling energy use from 1,126 MMBtu/year to 976 MMBtu/year, Increased the space heating energy from MMBtu/year to 727MMBtu/year, Reduced the total energy use from 5,554 MMBtu/year to 4,735 MMBtu/year, i.e., 819 MMBtu/year or total energy savings, Reduced the electricity use from 1,627,216 kwh/year to 1,387,338 kwh/year, i.e., 239,878 kwh/year electricity savings, and Reduced the peak demand from 4,183 kw to 4,477 kw.