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Modeling To Inform Design. IBPSA - USA. Integrated Design Process Modeling Procedures Case Studies. 1. Modeling and the Building Life Cycle. 2. Performance Impact. Level of Effort. Early Decisions Are The Most Important. Typical energy modeling timeframe. HIGH. Level of Effort.
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Modeling To Inform Design IBPSA - USA Integrated Design Process Modeling Procedures Case Studies 1
Performance Impact Level of Effort Early Decisions Are The Most Important Typical energy modeling timeframe HIGH Level of Effort LOW Project Start Project Finish Time 3
Integrated Design ProcessTime Comparison Construction Admin Construction Admin Project Closeout Project Closeout Pre-design Construction Documents Construction Documents Schematic Design Pre-design Design Development Schematic Design Design Development Typical Integrated 4
Integrated Design ProcessOverview Activities • Align team around energy-related goals • Make design recommendations EARLY to increase potential for impact • Identify where efforts should be focused to maximize energy savings and equipment downsizing • Maximize opportunity for energy efficiency Modeling Objectives 5
Integrated Design ProcessGoal Setting Use Energy Modeling to Quantify Targets Goal Setting Charrette 6
Integrated Design ProcessTechnical Potential • WHY DO WE CARE? • Challenges conventional ways of thinking • Not limited by industry benchmarks/norms • Leads to more aggressive design targets • Explicitly determines where ground has been lost WHAT IS IT?? The minimum level of energy consumption possible for a building, given today’s technology (excluding renewables). 7 HOW DO WE DETERMINE THIS? Start with a baseline or current design Removes the losses and inefficiencies with best available technology
Integrated Design ProcessThe Right Steps In The Right Order Most people start here! 8
Integrative Design ProcessSupporting the Business Case • Packages of measures • Downsize HVAC equipment • Identify packages that meet various goals • Include all cash flows • Identify “business as usual” baseline 10
Integrative Design ProcessSupporting the Business Case Peak Cooling Load Contributions Potential Cooling Load Reduction Evaluate heating and cooling load breakdowns to identify impactful load reduction measures….this is how you can downsize HVAC systems! ** Use “Design Day” Feature 11
Integrative Design ProcessSupporting the Business Case Show a path to a desired goal – communicate to the owner/architect early on that this is important! 12
Modeling to Inform Design IBPSA - USA Integrated Design Case Study: NELHA 13
NELHA Case StudyIntegrated High Performance Building AIA Top 10 Green Projects-2007 14
NELHA Regenerative Design Warm air Warm Air Cool Air Cool water Condensate water for irrigation 15
NELHA Annual Energy Use: 8.6kBtu/sf Annual Energy Cost Savings: $25,437 Indoor Potable Water Use: 11,700 gal/yr Indoor Potable Water Use Reduction: 73% Outdoor Potable Water Use: Zero LEED NC V2.1 Platinum Date Completed: November 2005 16
Modeling to Inform Design IBPSA - USA Supporting The Business Case Car Dealership 17
Car Dealership Case StudyEnd Use Breakdowns Hot & Humid Cold Winter Haven, FL Chicago, IL 19
Car Dealership Case StudySummary of Results • IMPACT OF Life Cycle Cost Analysis (LCCA) • Forced the dealers to consider metrics beyond SPP • Gave “credit” for downsizing HVAC • By considering integrated packages of measures, we were able to “finance” measures with non-quantifiable benefits • Improved thermal comfort • Increased sales and worker productivity from daylighting 20
Modeling to Inform Design IBPSA - USA Supporting the Business Case Empire State Building 21
Empire State Building (ESB) Application of Technical Potential www.esbsustainability.com 22
ESB Pre-Retrofit Prior to 2008, the Empire State Building’s performance was average compared to most U.S. office buildings. Annual utility costs: $11 million ($4/sq. ft.) Annual CO2 emissions: 25,000 metric tons (22 lbs/sq. ft.) Annual energy use: 88 kBtu/sq. ft. Peak electric demand: 9.5 MW (3.8 W/sq. ft. inc. HVAC) 23
ESB Process Motivation of ESB Ownership: To demonstrate how to cost-effectively retrofit a large multi-tenant office building to inspire others to embark on whole-building retrofits. 8 24
ESB: Technical Potential Exercise What is the maximum level of energy savings for this building given today’s technology? 90 kBtu/sf/yr Annual Energy Use 25 1 Current Energy Use
ESB: Technical Potential Exercise What is the maximum level of energy savings for this building given today’s technology? 90 kBtu/sf/yr 65% Savings Annual Energy Use Raise Cooling Setpoint Cooling Energy Use Envelope & OA Savings Reduce Internal Gains 2 EEMs Cooling Efficiency Cooling T-Min Existing Cooling 26 1 Current Energy Use
ESB: Technical Potential Exercise What is the maximum level of energy savings for this building given today’s technology? 90 kBtu/sf/yr Annual Energy Use 2 EEMs 4 Constraints 27 3 5 1 Technical Potential Implementable Minimum Current Energy Use
ESB: Technical Potential Exercise 29% not cost effective or implementable Baseline: 90 kBtu/sf/yr Implementable Minimum: 57 kBtu/sf/yr 67% Savings Technical Potential: 30 kBtu/sf/yr 28
ESB: Implementable Minimum Energy and CO2 savings result from 8 key projects. 38% Reduction 29
ESB Summary 30
Modeling to Inform Design IBPSA - USA Modeling Procedures 31
Modeling Procedures • How is energy modeling best utilized during each phase? • What are the key steps to be followed during each phase? 32
Modeling ProceduresPre-Design • Confirm critical assumptions and big picture analysis • Take what you know (footprint, building type, etc) and construct a 90.1-2007 model • Document all assumptions, note values to be validated • Evaluate the end-use breakdown to identify major savings opportunities • Evaluate peak heating and cooling load contributions to identify ways to downsize mechanical systems • Analyze certain measures that are early design decisions and will be difficult to change later • Determine the “technical potential” for reduced energy consumption to challenge the actual design 34
Modeling ProceduresSchematic Design • Review all available documents (Owner’s Requirements, Narratives, Drawings). Extract known data, document assumptions. • Compile schedules, LPD, EPD design data for team to review, get info for ASHRAE fan power calculation (filters, sound attenuation, etc.) • Evaluate those things that can’t be modeled with alternative methods (e.g. thermodynamic equivalent, spreadsheet, 8760 schedule, etc.) • Evaluate impact of change from “reference” to “technical potential” • Define several HVAC alternatives • Expand EEMs to include synergistic elements • Make series of runs that include one EEM at a time to facilitate QC • Define packages to cover range of targets • Check results against metrics (site, plant, end-use) and targets 36
Modeling ProceduresDesign Development • Update model input with latest design info, document assumptions • Identify any gaps in the plans & specifications (e.g. fenestration properties, fan bhp, sequence of operations, etc.) and request clarifications. • For lifecycle cost analysis or value engineering, identify efficiency measures already incorporated into the design, and use parametric cases to show performance without these measures • Identify and analyze efficiency measures not analyzed in earlier phases • Fine-tune efficiency measures in design • control parameters • exterior shade depths • chiller selection (using part-load curves) • Verify equipment capacities will meet comfort conditions without jeopardizing energy efficiency 38
Modeling ProceduresConstruction Documents • Check for changes to building form, orientation, or thermal zones • Verify envelope input parameters • Identify any changes to LPD, EPD, or schedules • Identify any changes to fan bhp, air flow, and other HVAC equipment • Identify any changes to controls • Revise model to reflect current design • Check results against DD results, metrics, targets • Ensure that documentation appropriately responds to information requested by Authority Having Jurisdiction • Provide full justification for all savings claimed • Provide a narrative justifying any non-standard inputs or outputs 40
Modeling to Inform Design IBPSA - USA Construction Documents Case Study UH C-MORE LAB 42
UH C-MORE Case StudyConstruction Documentation Reviews ASHRAE 90.1-2004 Goal of CD Reviews: To ensure inclusion of all sustainability measures and LEED points. CD Energy Modeling: Completion of Exceptional Calculation Measures. 43
UH C-MORE Case StudyCD Review 44 *EAc1 Optimize Energy Performance **IEQc1 Outdoor Air Delivery Monitoring
UH C-MORE Case StudyExceptional Calculation Method Heat Recovery Schematic 45