Effective Energy Modeling WGBA Leadership Conference October 19, 2005

Transcription

1 Effective Energy Modeling WGBA Leadership Conference October 19, 2005 Steven Carlson, P.E. CDH Energy Corp. Evansville, WI

2 Presentation Overview What Why How Illustrated by experiences in the Alberici World Headquarters LEED Platinum project

3 Experience Building Performance Energy Simulation Development Buildings Loads, part-load performance, etc Technologies (GSHP, Desiccants, Refrigeration, etc) Energy Technology Demonstration Field data Building Performance Metrics Commissioning Monitoring & Verification Energy Project Development Feasibility Studies Energy Management

4 Whole Building Energy Analysis Hourly simulation Comprehensive Integration Loads Systems Plant Economics Requires detailed design input to represent: Shell Systems Equipment Use

5 State-of-the-Art Software Review ARTI 2001 Whole Building Energy Analysis Only used regularly by 5% of respondents When client requires it Not well linked with tools already used Green Design Tools Previous experience (31%) Mfg. literature (20%) Rating system (13%) Energy Analysis & Code Compliance Tools Paper forms (27%) Mfg. software (18%) Previous experience (10%)

6 Tools Used Most Often HVAC Equipment Sizing: What Method Do You Use Most Often? Other.8% Mfgs' sizing softw ar 51.7% Manual J w orksheet 4.2% Bldg energy sim 6.8% 3rd party sizing sof 8.5% Other 11.0% Previous experience, 16.9%

7 ARTI Focus Group Findings HVAC loads software is common Design tradeoffs are evaluated in some cases Mostly glazing; lighting generally not considered Depends on when the ME is brought into the process Schedules don t permit much interaction between disciplines Design-build projects more likely to encourage collaboration Iterations, especially cost estimating, are time consuming Lots of software being used CAD Equipment selection / System sizing Cost estimating Lots of redundant data entry looking for data exchange

8 Why Use WBEA? Where simple load and sizing analysis is not enough: Daylighting benefits/tradeoffs Lighting / HVAC / Shell tradeoffs HVAC control issues (economizer, DCV) Geothermal Heat Pumps vs. other systems Dehumidification performance Natural /Mixed Ventilation Thermal storage

9 Whole Building Design Treat building as a system Interactions of design decisions (first cost & operating cost) architectural form, opaque shell, glazing, lighting, HVAC systems Example of benefits: Better windows vs. less HVAC Reduced lighting power density vs. less HVAC Requires Team Communications

10 Energy Modeling - Why? To inform design Options analysis To obtain LEED points Number one driver of energy modeling / Whole Building design process.energy savings? Who cares, just give me my points! To set performance targets Review building data (M&V) Baseline for energy management Alberici M&V plan with 5 min DDC data archive

11 To Inform Design Options Analysis To quantify options before design is finished Requires tradeoff between design details and assumptions Requires communication of intent Budget Schedule System performance requirements Requires model detail appropriate for analysis Need to build confidence in model results Parametrics Modeling is most appropriate for relative comparisons

12 Alberici World Headquarters Design Features Shell insulation R-19 metal frame R-30 roof Glazing: U=0.31, SHGC = 0.20 & 0.23 Lighting 0.64 W/sq ft building 0.20 W/sq ft parking garage Daylighting control (35 f.c.) HVAC System UFAD at 2.3 in wc static pressure Perimeter powered boxes for heat Variable speed supply fans Energy recovery ventilation with economizer mode Active humidity control Natural ventilation

13 Alberici World Headquarters Design Features Equipment - Cooling HCFC free screw chillers Variable speed tower Water-side economizer Variable speed secondary loop pumping Equipment - Heating Full modulating condensing boilers Interconnection to CHW coils for morning warm-up Domestic hot water solar preheat (380 sq ft) Renewable Electricity Production 65 kw Wind Turbine

14 To Obtain LEED Points Designed Building Budget Building Energy Regulated Energy Energy Peak Energy Peak Impact Summary by End Use Energy Type [kwh] [kw] [kwh] [kw] [%] Interior Lighting Electricity 162, , % Exterior Lighting Electricity 72, , % Space Cooling Electricity 106, , % Vent Fans Electricity 41, , % Pumps & ERV Fans Electricity 34, , % Energy Peak Energy Peak Impact [therm] [Btu/hr] [therm] [Btu/hr] [%] Space Heating Natural Gas 9,915 2,430,899 20,415 5,436,068 51% Service Water Heating Natural Gas ,801 1,181 34,801 62% Designed Building Budget Building Impact Source Source Energy & Cost Energy Cost Energy Cost Energy Cost Summary by Fuel [10 6 Btu] [$] [10 6 Btu] [$] [%] [%] Electricity 4,267 32,517 8,895 67,538 52% 52% Natural Gas 1,037 9,971 2,160 19,408 52% 49% Subtotal Non-Renew (DEC') 5,303 42,488 11,054 86,946 52% 51.1% Sutotal Renewable (REC') (951) (7,596) - - Total 4,352 34,892 11,054 86,946 Percentage Savings = 100 x (ECB'$-DEC"$)/ECB'$= 59.9% Credit 1 Points = 10

15 Alberici World Headquarters Energy Model Representation Daylighting analysis increased emphasis on geometry. HVAC zoning to match design

16 To Set Performance Targets Energy Management Whole Building Systems & Equipment Performance Model calibration vs system performance Schedules Operating parameters Performance curves M&V plan closes loop to verify performance Requires building operational data and analysis Alberici M&V plan with 5 min DDC data archive

17 Performance Targets - Patterns Hour of Day Hour of Day Total Building Power Operating Pattern JanFebruary March April May June July August Sep Day (MAX/MIN = / 0.00 kw) Total Building Power Operating Pattern - Energy Model Jan February March April May June July August Sep 2003 Day (MAX/MIN = / kw)

18 Performance Targets - Patterns Hour of Day Hour of Day Lighting Power Operating Pattern JanFebruary March April May June July August Sep 2005 Day (MAX/MIN = 83.00/ 0.00 kw) Lighting Power Operating Pattern - Energy Model Jan February March April May June July August Sep 2003 Day (MAX/MIN = 73.60/ 7.40 kw)

19 Performance Targets - Trends Weekday Sunday Saturday Simulation Daily Total Electricity Use 5000 kwh/day Daily Average Outdoor Dry Bulb Temperature (F) Model adjusted with extended operating hours

20 Performance Targets - Trends System by system performance trend reviews Proving fan modulation with plant heating and cooling loads 800 Fan Energy Heating/Cooling Load Relationship AHU Fan Electricity (kwh/day) Daily Net Heating(-) Cooling (+) Load (MMBTU)

21 Performance Targets - Trends Economizer operation reduces CO 2 levels Hour of Day HRU Unit #2 Return Air CO February March April May June July August September 2005 Day (MAX/MIN = / ppm) HRU #2 Return Air CO2 Concentration (ppm) February March April May June July August 2005

22 Summary Effective Modeling Adds value by integrating energy simulation into design process Options analysis Model informs the design Goes beyond modeling for points Modeling alone does not improve efficiency Provides a tool for energy management Baseline / Performance Targets Whole building System Equipment Sequence of Operations Close the loop data informs the model Build confidence in the process ready for next project