advancing codes, standards and bem tools to meet evolving ......1 advancing codes, standards and bem...

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Advancing Codes, Standards and BEM Tools to Meet Evolving Needs

SUPRIYA GOELPacific Northwest National LaboratoryNovember 13th, 2019

PNNL-SA-149141

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Progressive improvements in energy code…

Still far from net zero…Source : Roadmap to Commercial Energy Codes, Rosenberg et al, PNNL-24009

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Where are energy codes heading?

Several States, and cities are Targeting Zero Net Energy

Oregon: Solar Ready and Carbon NeutralityMinnesota: Zero Energy by 2030New York : Voluntary Stretch CodeCalifornia : Zero Energy by 2030And Delaware, Vermont…

Code cycles on ZNE in CASource: SCE & AEC 2009.

Prescriptive Paths

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Formats being used or being contemplated for energy codes…

Proposed Building

Mandatory Requirements Enhanced Mandatory Requirements or Backstops

Component Prescriptive

Ref: Roadmap for the Future of Commercial Energy Codes, Rosenberg et al, PNNL-24009

Energy Efficiency

Credits

Capacity Constraint

Performance: Equivalent or Differential

Outcome Based Compliance and Energy Use Reporting

Design and Construction Code Compliance for Occupancy Permit

Performance Paths

System Performance

Performance Based Codes

Various approaches to facilitate transition to net zero

Provide flexibility – through metrics, accounting for regulated/unregulated loads, renewable energy, trade-offs between systems

Require supported capabilities in BEM tools

Require reporting mechanisms

Require result verification and QA/QC processes

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Challenges Faced for Transition to Performance Based Codes….

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Usability

Multiple Baselines

Complexity

Lack of Standardization

Stringency

Allows Trade-OffsTrade-off between long-lasting envelope measures and, shorter lived HVAC controls. Free riders (like LPD allowance)

CA specific tools, rulesets and data standards : more work for practitioners

Complex requirements = complex software = complex verification and low confidence in results

Design analysis, compliance, beyond-code/certification, incentives

Reporting

Manual, repetitiveVague Submittal Requirements and a Lack of Standardized Compliance Forms

Verification

ChallengingMultiple BEM tools, 1000s inputs, difficult to crosscheck between model inputs and design drawings.

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Solutions being evaluated at PNNL to address all of these issues…

Usability Issue: Multiple Baselines

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ASHRAE 90.1-2016 Appendix G – stable baselineCompliance requires meeting a performance target below the baseline

Specific targets created for any code or beyond code program

90.1-2004 Baseline

90.1-2007 Baseline

90.1-2010 Baseline

90.1-2013 Baseline90.1-2016 Baseline

0.75

0.50

0.25

0

1.0

Net Zero

Future Codes

Stable Baseline (2004)

90.1-2007 Target

90.1-2010 Target

90.1-2013 Target

90.1-2016 Target

Stretch Code Target

T-24 2030

T-24 20XX

Stable Baseline Approach

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One model used for multiple purposesCreates a larger market for tools that automate the simulation process

Is simpler, cheaper, more likely to be accurate

Encouraging Electrification and De-carbonization –“It’s the metric”

Most code performance paths in the U.S. use energy cost as the metric for compliance

Current utility costs favor natural gas over electric heating

Conflicts with many state and city mandates to electrify and limit carbon emissions

Picking the correct metric helps meet policy goalsNYS Stretch Code – source energy

Washington State – carbon emissions

ASHRAE Standard 189.1 – source energy and carbon emissions

Metrics

$/unit (therm,kWh)1

. $/kBtu

Source Multiplier 2.

CO2e(lb/unit)

(therm,kWh)3.

CO2e(lb/kBtu)

Heating Eff (furnace/ASHP4.)

Site Energy

(kBtu/kBtu delivered)

Energy Cost ($/kBtu

delivered)

Source Energy(kBtu/kBtu delivered)

CO2e (lb/kBtu

delivered)

Gas Furnace 0.906 $ 0.0091 1.05 11.70

$ 0.1170 0.8 1.2500$

0.0113 1.313

0.15 Electric Heat Pump

0.1619 $ 0.0474 2.55 0.70

$ 0.2051 3.86 0.2591$

0.0123 0.661

0.05 *Relationship of Electric to Gas Results 21% 109% 50% 36%

*Greater than 100% favors gas furnaces over heat pumps1. EIA 2019 State Average2. EIA 2016 National Average3. Natural gas emmissions from EIA https://www.eia.gov/environment/emissions/co2_vol_mass.php. Electricity emmission from Brendon Owens (eGrid)4. Standard 80% efficient furnace, heat pump HSPF of 8.2, based on 90.1-2016 for <65,000 Btuh. Conversion to COPnf from Section 11. COPnfheating = –0.0296 × HSPF2 + 0.7134 × HSPF

Performance Rating Method (PRM) Can be Modified to Address CA Specific Requirements

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Electrification : Building Performance Factors : Can be developed using electric heating systems.

Metric: Source Energy

Net zero goalsAllow credit for >5% renewable energy

Can develop PCI targets with unregulated loads.

Limit Trade-Offs Between Long and Short Life Components

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Envelope backstop

Establishes mandatory envelope minimums below which no trade-offs are allowed

ASHRAE Standard 90.1 (approved for public review) and New York Stretch Code use similar approach

Washington State Approach – Maximum UA

Addressing Complexity in Code

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PrescriptiveSEER, AFUE, LED, LPD, Economizer, ERV, Motor Efficiency, Etc.

• Applies mostly to small and simple buildings

• Limited Options

• Doesn’t achieve deep savings

• Options limited with increased code stringency

Simple & inexpensive to implement

Whole Building Performance

Energy Modeling, Whole Building Integrated Design, LEED Certification,

• Applicable to large/ complex buildings

• Achieves deeper savings

• Unlimited options

• Flexible

Complex & expensive to implement

“THE GAP”

System PerformanceCompare energy to system delivery

• Applicable to a range of buildings

• Includes system effect

Simple to implement

Addressing Complexity in Code: System Efficiency

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…

Lighting

….

SHW System

Fan Systems

Source: http://www.hpbmagazine.org/System-Level-Key-Performance-Indicators/

http://www.hpbmagazine.org/System-Level-Key-Performance-Indicators/


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Envelope90.1 Appendix C : Prevents trading-off envelope efficiency with HVAC systems

LightingNew approach, being evaluated by 90.1 Lighting Subcommittee

kWh approach – allows trade-offs between lighting power and controls

𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃 𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴 𝑘𝑘𝑘𝑘𝑘 = 𝐿𝐿𝐿𝐿𝐿𝐿𝑘𝐿𝐿𝐿𝐿𝐴𝐴𝐿𝐿 𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃 × 𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴 𝑂𝑂𝑃𝑃𝑃𝑃 𝐻𝐻𝑃𝑃𝑃𝑃 × 𝐶𝐶𝑃𝑃𝐴𝐴𝐿𝐿𝑃𝑃𝐴𝐴 𝐹𝐹𝐴𝐴𝐹𝐹𝐿𝐿𝑃𝑃𝑃𝑃𝑃𝑃

𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃 𝑘𝑘𝑘𝑘𝑘 < 𝐵𝐵𝐴𝐴𝑃𝑃𝐿𝐿𝑃𝑃𝐿𝐿 𝑘𝑘𝑘𝑘𝑘

HVAC Total System Performance Ratio (TSPR) – allows trade-offs between HVAC components and controls

𝑇𝑇𝑇𝑇𝑃𝑃𝑇𝑇 = 𝑆𝑆𝑆𝑆𝑆𝑆 𝑜𝑜𝑜𝑜 𝐴𝐴𝐴𝐴𝐴𝐴𝑆𝑆𝐴𝐴𝐴𝐴 𝐵𝐵𝑆𝑆𝐵𝐵𝐴𝐴𝐵𝐵𝐵𝐵𝐴𝐴𝐵𝐵 𝐻𝐻𝐻𝐻𝐴𝐴𝐻𝐻𝐵𝐵𝐴𝐴𝐵𝐵 𝐴𝐴𝐴𝐴𝐵𝐵 𝐶𝐶𝑜𝑜𝑜𝑜𝐴𝐴𝐵𝐵𝐴𝐴𝐵𝐵 𝐿𝐿𝑜𝑜𝐴𝐴𝐵𝐵𝐿𝐿 (𝑘𝑘𝐵𝐵𝐻𝐻𝑆𝑆)𝐴𝐴𝐴𝐴𝐴𝐴𝑆𝑆𝐴𝐴𝐴𝐴 𝐻𝐻𝐻𝐻𝐴𝐴𝐶𝐶 𝐸𝐸𝐴𝐴𝐻𝐻𝐸𝐸𝐵𝐵𝐸𝐸 𝐼𝐼𝐴𝐴𝐼𝐼𝑆𝑆𝐻𝐻 (𝑈𝑈𝐿𝐿𝐻𝐻 𝑜𝑜𝐸𝐸 𝐶𝐶𝑜𝑜𝐿𝐿𝐻𝐻 𝑜𝑜𝐸𝐸 𝐶𝐶𝐶𝐶𝐶 𝐸𝐸𝑆𝑆𝐵𝐵𝐿𝐿𝐿𝐿𝐵𝐵𝑜𝑜𝐴𝐴𝐿𝐿)

𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃 𝑇𝑇𝑇𝑇𝑃𝑃𝑇𝑇 > 𝐵𝐵𝐴𝐴𝑃𝑃𝐿𝐿𝑃𝑃𝐿𝐿 𝑇𝑇𝑇𝑇𝑃𝑃𝑇𝑇

Similar to ASHRAE Appendix G…Baseline is a “reasonably efficient” system for each building type

Trades within HVAC system onlyNot trading better HVAC for worse envelope

Simplified Building Energy ModelUses simplified building geometry & defaults

Limited design team effortTSPR requires 2 to 6 hours

Whole building simulation is likely 75 to 100+ hours

…with some differences

And how does a building get a TSPR?

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Adopted by Washington State Energy Code

Uses CO2 emissions instead of energy cost or energy use.

TSPR Ruleset has been implemented into DOE’s Asset Score tool.


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New approach proposed by PNNL

No ‘Prescriptive Requirements’

‘Enhanced Mandatory Requirements’ with minimum prescribed system efficiency for envelope, lighting and HVAC

100% Performance Based Codes

Proposed Building

Enhanced Mandatory Requirements

Envelope Trade-Off

HVAC TSPRWhole Building

Performance DifferentialLighting System

Performance

Addressing Complexity in Code: SEM

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Simplified Energy Modeling Ruleset (SEM)

New Project 2019-2022• Appropriate for small, simple buildings

• Reduces modeling time and cost • Standard Appendix G model for 50,000 ft2 project can require 75-100 hours

• Simplified Energy Model may be 2-6 hours

Typical App G Energy Model Simplified Model

Addressing Complexity in Code: Energy Credits

Stakeholders have expressed the desire to maintain simple, prescriptive solutions

Precalculated ‘Energy Credits’ : Likely in IECC 2018, being evaluated by Standard 90.1

10 credits equals 2.5% energy cost saved

Additional Energy Efficiency Credits for Group B Occupancies

Climate Zone: 1A 1B 2A 2B 3A 3B 3C 4A 4B 4C 5A 5B 5C 6A 6B 7 8

C406.2.1: 5% Heating NA NA NA NA NA NA NA NA NA NA 1 NA NA 1 1 NA 1

C406.2.2: 5% Cooling 6 6 5 5 4 4 3 3 3 2 2 2 1 2 2 2 1

C406.2.3: 10% Heating NA NA NA NA NA NA NA 1 NA NA 2 1 1 2 2 NA 1

C406.2.4: 10% Cooling 11 12 10 9 7 7 6 5 6 4 4 5 3 4 3 3 3

C406.3.1: 10% LPA 9 8 9 9 9 9 10 8 9 9 7 8 8 6 7 7 6

C406.4:Digital Lt Ctrl 2 2 2 2 2 2 2 2 2 2 2 2 2 1 2 1 1

C406.5: Renewable 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9

C406.6: DOAS 4 4 4 4 4 3 2 5 3 2 5 3 2 7 4 5 3

C406.7.1: SWH HR NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA

C406.7.2: SWH NG eff NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA

C406.7.3: SWH HP NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA

C406.8: 85% UA 1 4 2 4 4 3 NA 7 4 5 10 7 6 11 10 14 16

C406.9: Low Leak 2 1 1 2 4 1 NA 8 2 3 11 4 1 15 8 11 6

Reporting and Verification:Ensure Accurate Performance Model Submittals

PNNL project FY 18-20

Stakeholder SurveyQ: Near term tools and resources to facilitate performance based compliance

Source: Karpman, Maria, ‘High Priority Tools to Facilitate Compliance with ASHRAE Standard 90.1 2016 Section 11 and Appendix G’

Q: Long term goals for facilitating performance based compliance


PNNL project FY18-20

Developing QA/QC tools to help jurisdictions and program administrators verify the accuracy of performance based compliance

Reporting template and checklists

Building parameters input with reference to design documents and simulation reports

Automated compliance calculations

Built-in look ups of code requirements

Submittal review manual

Long term goal :Support development of standardized reporting schema which could be used to pre-populate the reporting forms for different programs.


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New Proposed ASHRAE Standard

“Protocol for Evaluating Ruleset Implementation in Building Performance Modeling Software”

• Would provide tests and acceptance criteria for implementation of rulesets and related reporting in building performance modeling software

• Status• Sponsored by TC 4.7- Energy Calculations

• Co-Sponsored by TC 7.6- Building Energy Performance

• Approved by ASHRAE Standards Committee, waiting for ASHRAE BOD approval.

• 3-year agenda (2020-2022) I/O schema + 90.1 Appendix G ruleset checker

• Continuous maintenance

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User’s Model (UM)

PMInput/Output

Report

Proposed Model (PM)

UMInput/Output

Report

PM Sim Results

BMInput/Output

Report

Baseline Model (BM)

BM Sim Results


I/O ruleset checking tool

Vendor Model + Simulation Results to I/O Converter

Ruleset Implementation

Source: Roth, Amir, ‘Automating Compliance Modeling – Challenges, Opportunities and Path Forward ’, ASHRAE Building Performance Analysis Conference, Denver, CO 2019

To Summarize…

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Usability

Multiple Baselines

Complexity

Lack of Standardization

Stringency

Allows Trade-Offs

System Efficiency, SEMEnergy Credits

Stable baseline approach

Reporting

Manual, repetitive Standardized reporting templates

Verification

ChallengingASHRAE Ruleset Standard

Standardized Reporting Templates

Standardized QA/QC Tools, PRM

ASHRAE Ruleset Standard

System EfficiencyPRM + Envelope Backstop

Thank you

advancing codes, standards and bem tools to meet evolving ......1 advancing codes, standards and bem...

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