Objective. Energy Modeling User s Group: Modeling Review and Q/C. Why? Outline. The model plan 3/24/2011

Transcription

1 Energy Modeling User s Group: Modeling Review and Q/C Sharon Gould Keith Swartz Zach Obert Objective What is quality assurance Why is it important What is required to get there Steps to maintain quality Checking the quality 1 2 Outline Planning the Model Third Party Modeling Review Hold major questions to the end Why? Deliver a quality project that is: On time Within budget Matches internal and external expectations 3 4 The model plan Plan the Work Planning the model Sharon Gould, PE Franklin Energy Services Define Objective Layout Scope of work/ deliverable Identify software package Identify the affected variables Identify measure order Write down plan 5 6 1

2 The model plan Understanding the scope of work Build the model Review the baseline Work the Plan Review Build the the final measures results Build the report Present to customer How close do the results need to be? Schematic/ Budget Decisions Design Development Decisions Demonstrating Compliance (record keeping exercise) Guaranteed savings What are the customer s expectations? What is the model being used for? Level of effort vs. outcome Understand the deliverable/ report 7 8 Defining the scope of work Information available Margin of error for different variables Limitations of the software program Workarounds Complexity of the system Hire your modeling engineer as a sub don t assume they understand the scope of work Writing down the plan If you did this model again, would you get the same results? Consistency/ Predictable results Tracing the work history Simplify the time in the modeling software 9 10 Reviewing the results What does it look like? Benchmarking/ Trends? Does this building type use this much energy? Relative BTU savings per measure Was the correct code/ standard used? How much energy does an ERV really save? Does the model match the plan? DOES THIS MAKE SENSE? WHY?

3 Tools Develop checklists/ Pre calculators Summary Understand customer expectations Develop model measure tracking EUI/ DOE Energy Star Other models of building type, weather Develop an effective path Provide only what the customer is looking for A place to understand the data Keith Swartz, PE Energy Center of Wisconsin Use the built in software checks equest Tools Check Building Description (syntax errors) Tools Quality Control Reporting QC Summary tab identifies areas of concern QC Details tab identifies specific concerns TRACE Calculate and View Results Scan for Errors After simulating, check load rules of thumb Airflow cfm/sq ft Cooling Airflow cfm/ton Peak Cooling sq ft / ton Peak Heating MBH/sq ft OA Fraction %OA Check equipment operating hours equest: PS H (plants), SS P (unitary) TRACE: System Load Profiles Calculate load factor = kwh / kw full load equivalent hours Higher for 24/7 operation

4 Check unmet load hours & space temperatures equest SS F Hours underheated & overcooled BEPU Hours plant load not satisfied BEPS Hours outside throttling range SS E Simultaneous heating & cooling SS O Space temperatures TRACE Building Temperature Profiles LEED Summary Other equest checks ATTN report lists errors, warnings, and cautions If simulation aborted by a run time error, search for error in.bdl file Can create Hourly Reports to help troubleshoot Check loop temperatures of geo systems For complex ventilation systems Compare utility consumption to typical Dept. of Energy s Commercial Building Energy Consumption Survey (CBECS) Energy Use Intensity (EUI) = kbtu/sq ft per year kwh/sq ft per year therms/sq ft per year $/sq ft per year W/sq ft (older data) Adjust expectations if not all systems are modeled (DHW, outside lighting) Check monthly patterns equest: Monthly Energy Consumption by Enduse TRACE: Equipment Energy Consumption Hl Helps to identify schedule problems

5 Evaluating Upgrades Run each change independently Bundling can hide an energy loser if combined with winners Easier to identify irregularities The order of the upgrades makes a difference in the energy numbers Upgrades get a larger share of the credit of the cumulative savings when they are evaluated earlier than if they are evaluated later Evaluating Upgrades Ask yourself if values should increase or decrease. Not everything will decrease! Lighting & daylighting improvements have less waste heat Higher gas consumption in winter No net savings in winter if electric heat Increased insulation in internal load dominated buildings Savings in summer & winter, but higher consumption in spring & fall, especially if no economizer Caution The computer might be changing more than you think Condensing boiler and reset schedule, the program automatically changed the hot water reset schedule hdl Hidden assumptions in the program Have someone else look over your results! You are too familiar with it to find mistakes, especially big picture items you have overlooked rd Party Energy Modeling Review Third Party Model Review Zach Obert, PE Wisconsin Energy Conservation Corporation E.g., project manager or other party not directly involved in doing modeling Modeling reports should be able to: Beeasily easily understood by someone not involved in the project Provide sufficient detail to make further decisions Demonstrate that project / program requirements have been followed Show what baseline was followed and why

6 Energy Modeling Report Details Brief overview of the project General project information: sq ft, utility rates, date/version control, hours of operation, modeling software used, contact info Rendering or floor plan Appropriate details related to why doing modeling (utility incentives, LEED, owner requirement, etc.) Energy Modeling Report Details Detailed description of energy saving measures Specific properties for baseline and proposed Sizes, capacities, other key features Can you understand what the measure is? Energy used, demand, and cost for baseline and proposed by energy saving measure Keep track of energy saving measures that have been ruled out Be able to go back a year from now and know what was done Making Sense of the Results Review key performance indicators: Energy cost / sq ft % energy cost savings kbtu / sq ft / year Does gas / electric use change by reasonable amount and in the correct direction? Change in energy use between measures Change in energy use overall Making Sense of the Results Grammar, spelling, formatting, math errors Were goals of the project met? Anything look unusual? Ask for more explanation if don t understand Provide detailed feedback in writing Request responses in writing Clear timeline for comments and responses Questions? Plan the work and work the plan Look for issues with the model and troubleshoot them Assure the deliverable meets the customers needs 35 6