Variable Speed Heat Pumps

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Variable Speed Heat Pumps. Provisional UES Proposal Presentation to the Regional Technical Forum September 18, 2012 Presentation by Kacie Bedney, Bonneville Power Elizabeth Daykin, Bonneville Power Ben Larson, Ecotope. Overview. - PowerPoint PPT Presentation

Text of Variable Speed Heat Pumps

  • *OverviewHeat pump measures applicability clarified to exclude variable speed heat pumps (VSHP) at May 2012 RTF meeting83 VSHP systems reported to BPABPA is conducting research to establish savings for this measure

  • *Measure SummaryMeasure name: Variable Speed Heat PumpsMeasure Sponsor: BPAMeasure description:Installation of high efficiency variable speed air source heat pumps to replace an electric forced air furnace. 12 HSPF / 18 SEERRequesting Status: Provisional

  • Measure Classification*

  • Measure Identifiers*

  • Baseline SpecificationsTwo baseline HVAC systems:Electric Forced Air Furnace - w/ and w/o ACASHP - 8.5 HSPF 14.0 SEERPTCS controls, commissioning, and sizing in baseThree building types (weighted):1,344 ft2 single-story ranch house (5%)2,200 ft2 split-level house (67%)2,688 ft2 house with basement (28%)


  • Baseline Specifications ContdLast measure in existing houses weatherized, lighting upgradedSame characteristics as those used for GSHP analysis


  • VSHP Performance Model: SEEMEcotope developed based on the Carrier Corporation 25VNA InfinityTM VSHP HSPF 12, SEER 18Product specification sheet provides: input power and output capacity at 10F increments for both min & max indoor air handler flowMin and max inputs and outputsPrevious work basing performance model from spec sheet data suggests assessment is likely optimistic - field & lab work needed.*

  • Carrier Spec Sheet Data*

  • Curve FitsPerformance curve fitted to spec sheet data using regression techniquesInput = (Tout, Trp, CFM)Output = (Tout, Trp, CFM)Currently, no cooling curve fit. Cooling improvements assumed to occur in proportion to heating improvements.*

  • Variable Capacity Considerations: Controls & AirflowAssert HP controller follows house loadAssert it is similar to observed DHP behaviorEx: If VSHP runs for 45 mins at full output for 1 hour, in the next hour it runs at 75% output for 1 hour.Airflow is a function of capacity and changes every hour within simulationDuct losses vary with varied airflowThis model shows ~5% increase in duct losses over a single speed system*

  • Example Simulation Output2200ft2 house with UA= 475 Btu/hr-FHeat pump size = 3 tonsEugene, OR climate. January 10-11.*

  • *

  • *Higher duct losses for VSHP when operating at lower airflows requires more overall heat outputHigher COP for VSHP system requires less energy inputCapacity changes based on load.Min capacity is ~40%

  • Measure Cost Summary*Baseline costs for upgrade and conversion rely on air-source heat pump analysesVSHP costs are from customer invoicesUpgrade $2,851 incremental costConversion incremental costFAF w/ CAC $5,616FAF w/o CAC $6,975

  • Measure Life SummaryMeasure life of 20 yearsAvailable default EUL*Sunset Criteria:Measure shall sunset at the end of 2014, at which time the field work and lab testing results will inform updated SEEM runs

  • Cost Effectiveness*

  • Checklist*

  • Checklist contd*

  • Plan for Data Collection and Analysis laboratory testingLab testing for performance curves Spring/Summer 20132-ton outdoor unit, 2 to 3.5 ton indoor unit AHRI ref # 4618711Tested at high, intermediate and low compressor speedsTested over a range of indoor and outdoor conditions (ODT 17 deg 62 deg)AHRI steady state heating tests


  • Plan for Data Collection and Analysis: field testBPA-led advisory committeeCommittee to assist in developing:method for evaluating the performanceappropriate M&V planwhat data to collect what & how to measureduration of the testsnumber of sites to testCombine lab and field testing into SEEM model to determine annual estimated savingsWinter 2013


  • ContactsBPAKacie Bedneykcbedney@bpa.gov503.230.4631EcotopeBen Larsonben@ecotope.com206.322.3753 x207

    *Stephanie Vasquezsmvasquez@bpa.gov503.230.3492

  • RTF Proposed Motion: I _________ move that the RTF approve the Residential VSHP UES Measure as Provisional with Active status.*