DNV GL © 2015-05-12 SAFER, SMARTER, GREENER1 DNV GL © 2015-05-12 HVAC-4 Webinar at CPUC

2015-05-12

ENERGY

HVAC-4 Deemed Measures Study, Year 1

Public Webinar

for California Public Utilities Commission

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Presentation Outline

Study Objectives

Measure selection

Literature review

Description of Crystal Ball® analysis tool

By Measure

– Background Information

– Results

– Recommendations

Year 2 study plans

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Study Objectives

Select 3 deemed measures to study

Perform literature review for each

Perform Monte Carlo simulations of ex ante savings using Crystal Ball®

Identify input parameters in need of updates or information gaps

Inform other HVAC Roadmap data collection efforts

Suggest study plans for Year 2

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Measure Selection: HVAC Roadmap Savings

Top 5 Natural Gas Saving Measures

Top 5 Annual Electric Saving Measures

Rank Measure GroupPreliminary Ex Ante

Savings, therms

1 HVAC Furnace 2,830,079

2 HVAC Duct Sealing 1,578,223

3 HVAC Boiler 1,427,112

4 HVAC Controls: Energy Management Systems (EMS) 875,857

5 HVAC Controls: Thermostat 470,346

Rank Measure GroupPreliminary Ex Ante

Savings, kWh

1 HVAC Rooftop or Split System 37,981,291

2 HVAC Motor Replacement 28,987,677

3 HVAC Chiller, Water-cooled 22,339,413

4 HVAC Chiller, Air-cooled 21,756,495

5 HVAC Fan Variable Frequency Drive (VFD) 17,612,888

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Measure Selection: HVAC Roadmap Measure Trends

Quarterly Natural Gas

Savings Claims

Quarterly Electric

Savings Claims

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Measure Selection: Selection Criteria

Selection Criteria

Residential Furnaces

Residential QM & Blower Motor Replacements

Mini-Splits and VRF Systems

Electric Gas Electric Gas Electric Gas

High savers in HVAC Roadmap?False(but

growing)True False False True False

Growing participation? True(particularly with VSMs)

True True

Not currently being evaluated? True True False(during HVAC-1 pilot)

ESPI measure? False True True

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Literature Review Process

Review IOU workpapers

Review secondary sources

Identify information gaps

Identify opportunities for improvements

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Description of Crystal Ball Analyses: General

Crystal Ball is an add-in for Microsoft Excel®

Monte Carlo simulation was named for Monte Carlo, Monaco

When rolling a single die, the roller knows that a 1, 2, 3, 4, 5, or 6 will result, but

cannot know the outcome for any given roll.

To set up Monte Carlo simulations, define the conditions of the input variable—in

this case, an integer between 1 and 6, incl.

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Description of Crystal Ball Analyses: Simulating a Single Die Roll

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Description of Crystal Ball Analyses: For Ex Post/Ex Ante Comparison

Snapshot of deemed savings from sample workpaper:

Snapshot of gross savings reporting table from CA Evaluation Framework1:

1 “The California Evaluation Framework,” TecMarket Works Framework Team for Southern California Edison Company, June 2004. (p. 380)

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Residential Furnaces: Background (PG&E)

For central, natural gas furnaces1 with ≥ 95 AFUE and < 97 AFUE

– w/variable-speed fan motors (and w/o)

Annual natural gas deemed savings based on 2011 DEER2 database

Electric deemed savings assume baseline equipment = constant volume fan

1 “High Efficiency Furnace 95 AFUE (1.04 HIR)—Residential,” Pacific Gas & Electric Company, 8/28/2012.

2 “Database for Energy Efficient Resources,” at http://www.deeresources.com/

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Residential Furnaces: Retrofit Prototypes Used in DEER

eQUEST prototype models:

Multifamily Building Prototype

Mobile Home Prototype

Single Family Home Prototype

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Residential Furnaces: Input Parameters VSMs

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Residential Furnace VSMs: Simulation Results

Monte Carlo simulation results:

Deemed Savings per PG&E workpaper:

Statistical Descriptors

Annual Electric Savings, kWh

CZ11 CZ12 CZ13

PG&E Workpaper 315 224 297

Simulated Mean 320 225 297

Standard Deviation 141 107 134

Coefficient of Variation 0.44 0.48 0.45

Minimum 131 85 149

Maximum 705 547 675

Mean Standard Error 1.41 1.07 1.34

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Residential Furnace VSMs: Simulation Results

Annual Electric Savings Distribution by Dwelling Type in CZ11

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Residential Furnace VSM: Monte Carlo Simulation Results

Savings Variance Contributions for Single Family Homes in CZ11

In most cases, building vintage accounted for the majority of the variance

Thermostat usage bin weights are the next highest contributor to the variance.

Savings at SFM buildings vary significantly by the number of stories.

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Residential Furnace & VSM: Recommendations

Assess average blower motor power during non-cooling modes for the baseline and post-retrofit case

Update building vintages represented in the participant population

Update thermostat usage bins and associated weights

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Residential Quality Maintenance & Blower Motor Retrofits: Background

Residential Quality Maintenance Measure Components by IOU

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Residential Quality Maintenance & Blower Motor Retrofits: Background

Residential Quality Maintenance Measure Components by IOU

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Residential Quality Maintenance: Workpaper

Source: PG&E Workpaper

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Residential Quality Maintenance: Background

Annual Electric Energy per Ton, Baseline and Post-Measure, in CZ03*

* Excludes blower motor replacement

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Residential Quality Maintenance: Comparison to Deemed Savings

Simulated Savings and Ex Ante Annual Electric Energy Savings, per Ton

• The annual electric energy estimates are within 25% of the ex ante savings in all climate zones except CZ12

• For peak demand, the simulated savings and ex ante savings in all climate zones except for Climate Zone 1 are within 25%.

• For natural gas energy, however, the ex ante savings are significantly higher than the simulated savings.

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Residential Quality Maintenance: Sensitivity Results

Sensitivities of Baseline Annual kWh, kW and therms consumptions

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Residential Quality Maintenance: Recommendations

Update thermostat offset values and weights based on the 2009 RASS

Verify distributions of duct UAs and furnace AFUEs

Verify building shell Uas

For those ex ante savings that differ significantly from the simulation results, hold a working session with the PG&E workpaper authors to identify the source of the discrepancies

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Mini-Split and Variable Refrigerant Flow Systems: Background

Mini- and multi-split units:

– Ductless split systems <65 kBtuh of cooling capacity

– Minimum seasonal energy efficiency ratio (SEER) rating of 16-22

Variable Refrigerant Flow (VRF) systems with inverter-driven compressors to vary refrigerant flow during part-load conditions:

– In systems of single- or multi-zone configurations

Fan coil units with electronically commutated motors (ECM) to vary the fan speed during part-load conditions

Heat recovery configurations that capture inverter waste heat removed from zones being cooled and diverting the captured heat to zones being heated

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Mini-Split Systems Background: SCE Methodology

At systems installed at commercial applications:

– Savings are scaled based on DEER savings for a 14 SEER package system at a single family home prototype

– Additional savings are included based on duct sealing savings to account for the ducted to ductless conversion

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Mini-Split Review

With savings based on DEER values and secondary sources Monte Carlo Analysis cannot be conducted

There is insufficient data available for savings associated with these measures. Basing savings on single family home DEER prototype may yield a rough estimate of savings, but is not necessarily representative of commercial applications. The question is how valid is this relationship:

– No secondary sources were provided in the workpaper to support the validity of this relationship.

– Each DEER Savings value has error associated with it, this will propagate through the calculation

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Mini-Split Review

Three studies are referenced for duct sealing savings with savings ranging from 10% to 18%.

– These savings values are from conditioned air leaking to unconditioned spaces The conversion from ducted to ductless systems will only result in fan savings

– SEER ratings already account for ductless systems operating with lower static pressure

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Mini-Split Recommendations

– Further study regarding whether the increased energy savings that go hand-in-hand with an improved SEER rating scale up at the same rate when installed at commercial applications as at residential ones

– Further investigation regarding the energy savings from the elimination of ductwork are already accounted for by the higher SEER ratings of ductless mini- and multi-split heat pumps

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VRF Workpaper Methodology

2011 DEER does not provide savings for VRF measures

2 cases are considered: 1) commercial VRF units or systems with heat recovery and 2) commercial VRF units or systems without heat recovery.

Savings are determined by running EnergyPro® v5.1 building simulations

Two assumptions are made:

– The equipment was manufactured by either Daikin or Mitsubishi, the two largest manufacturers of VRF equipment.

– Half of the zones in the building models were served by ducted systems and the other half by ductless units. This assumption was based on the sales proportions provided during interviews with Daikin and Mitsubishi representatives.

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VRF Review Recommendations

Gather ex post evaluation data to verify VRF deemed savings

Use EnergyPro® v5.1—with adjustable performance curves—instead of fixed SEER ratings

Through HVAC-1 evaluation, consider gathering:

– Proportions of ducted and ductless zones in commercial spaces

– Cooling capacities of these zones

– Typical lengths of duct runs in ducted zones

Field or Lab tests could greatly improve these measures to:

– Gather data regarding the full range of commercial building types, occupancy types, and associated load profiles. Alternatively, since the tracking data do not contain consistent building type fields, improving the tracking of participant building types would greatly facilitate the identification of building simulation models

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Year 2 Plans

Based on Year 1 findings:

Review 2014 tracking data for any new trends to inform future efforts

Further investigate measures that have been examined in Year 1

Gather underlying data used for the DEER parametric runs to facilitate running Monte Carlo simulations on parameters that feed into models

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Posting Comments http://www.energydataweb.com/cpuc/search.aspx; select “2013-2014” program cycle and search “HVAC”.  Public comment may be posted to the Public Document Area through Friday May 15, 2015.

Rachel MurrayRachel.murray@dnvgl.com510-891-0446