Research Strategy Review:Heat Pump Water Heaters

Thermostatic Restriction Valves

Jennifer AnzianoRTF R&E Subcommittee

July 8, 2015

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Overview

Reviewing two Research Strategies • Thermostatic Restriction Valve• Heat Pump Water Heaters

• Thoughts on the Research Strategy format?

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Background

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What is a Research Strategy?

• Used to inform deficiencies and related data needs for non-Proven measures

• Focuses on priority research objectives– What data does the RTF need for the measure to be proven?

• Outlines a potential data collection and analysis approach for addressing objectives– What might this research look like?

• Provides an estimate cost range to inform prioritization (based on potential approach)

• Does not intend to prescribe a specific, single approach for researchers

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What Does RTF Adoption of a Research Strategy Mean?

• RTF agrees with the research objectives and that strategy outlines a reasonable approach to addressing those objectives

• RTF recognizes that researchers define their own research and actual research may look different than outlined in strategy

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Role for R&E Subcommittee in Reviewing Research Strategies

• Provide feedback on whether outlined data collection and analysis approach is reasonable or whether:– Alternative approach might equally (or better) address research

objectives while being more practical (i.e. at a lower cost)

– Existing research already exists to inform some parameters (i.e. research not yet identified by staff or technical subcommittee)

– Unreasonable (or unrealistic) to research a defined parameter

– Whether proposed approach and estimated cost range match

• Typically, technical subcommittee is best group to inform research objectives for measure

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Thermostatic Restriction Valve

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Technology Description

• Showerers typically turn on water and wait for water temperature to rise before jumping in, resulting in two kinds of waste:– Structural waste: plug of cooled off water in hot water pipe

– Behavioral waste: additional water used after temperature rise, but before shower

• Device reduces behavioral waste by slowing shower flow to a trickle once the hot water reaches the valve

• Device is installed in-line between shower arm and shower-head and can be coupled with low-flow showerhead

• Evolve Technologies’s ShowerStart TSV is the only product currently on the market

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Determining Electric Savings• Hot water savings per shower event

– Showerhead flow rate (gpm)

– Behavioral waste savings (minutes)

– % Hot water (during warm-up)

– % of Shower (vs tub) start

• Shower events per year– Showers per person

– People per shower

• Hot water intensity– Change in temperature of hot water

– Water heater recovery efficiency

• Removal rate

Better data is needed to inform these parameters

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Measure Identifiers• Market Segment (2)

– Residential

– Health Care and Assisted Living

• Delivery Mechanism (3)

– Direct install

– Retail

– Mail

• Equipment Type (2)

– Valve only

– Valve and low-flow shower heads

• Hot Water Type (3)

– Electric resistance

– Electric heat pump

– Any (including gas)

More data will be informative for these identifiers

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Proposed Research Strategy1. Meter 60 baseline homes (30 per market segment)

– Collect: Flow rates, water temp at showerheads, fraction of “tub starts”

– Purpose: Inform behavioral waste and tub/shower starts parameters2. Meter 60 participant homes (30 per market segment)

– Collect: Flow rates, water temp at shower heads, fraction of “tub starts”

– Purpose: Validate performance and observe any difference in frequency of tub starts

3. Conduct pilot program with evaluation (several hundred per delivery mechanism and market segment)– Collect: Storage/removal (perhaps by phone survey) and showerhead

flow rate, DWH type, and shower/tub type (perhaps by direct install)– Purpose: Validate removal rate parameter and others

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Discussion

• Does the data collection and analysis approach appear reasonable?– If not, which aspect(s) should be refined?

• Is there an alternative approach that might better address research objectives?

• Based on the proposed (or discussed) approach, what is the appropriate estimated cost range?

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Heat Pump Water Heaters

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Objective for Today

• Res HPWH measure already has existing research strategy that was adopted at April 2015 RTF meeting– Existing strategy deals with HVAC interaction factor

• Now seeking to add a second objective to the existing strategy

• Scope for Today: Seeking feedback on portions of the Research Strategy related to the second objective

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• Staff is proposing to add a new performance tier (Tier 3) based on new product in the market

• Currently, only one product is available at Tier 2 or Tier 3

• RTF staff believe more data based on real world use of HPWHs is required to appropriately model new products in SEEM– Previously, performance characteristics used

in SEEM for all HPWH models have been calibrated to field data to reflect “real world” performance and savings

– Only DOE lab test data is currently available for this new product

Background

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Why More Data is Required

DOE lab tests do not appear to do a sufficient job of reflecting how these units perform in the field• DOE draw patterns are somewhat artificial and not reflective

of in situ draw patterns• Ecotope compared lab calibrated results to field calibrated

results for older GE tank and found:– Significant underestimation of resistance element use – Overestimation of heat pump use

• Evidence that manufacturers “design to the tests” for higher rated COPs

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Add an additional lab test to the existing DOE suite that uses “real world” water draw patters from existing field data

Perform new lab test on two older tanks for which we already have

field data

Compare the calibrated

performance characteristics

between the new lab test and the field data

If results compare well, use new lab test going forward

on new models coming to market

Proposed Research Strategy Goal

• RTF staff recognize that it is not practical to conduct field tests for every new model

• Seeking a solution that will give us a better answer, yet be more sustainable in the long term

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Discussion

• Technical subcommittee agrees with the need for research and is strongly supportive of this approach

• Seeking R&E Feedback on:– Is this a reasonable to collect the necessary data

to inform the measure long term?– Are there other suggestions for research to better

address the data need?

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Meeting Wrap Up

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Final Thoughts

• Feedback on:– New Research Strategy template?– Scheduling of monthly meetings?

• Next R&E Subcommittee meeting scheduled for August 6, 2015– Likely topic: Research Strategy for SEEM

calibration– Agenda will be confirmed one week out