Heat Pump Water Heaters: Tier 2 – Ducted Interior Installations

Provisional UES Proposal Regional Technical Forum

February 14th, 2012

UES Analysis by: B. LarsonRTF Staff Review by: A. HadleyPresentation by: A. Hadley, J. Harris

2

Background

• In October 2011, Provisional UES approved for heat pump water heater (HPWH) for: – Northern Climate Specification Tier 1

• Buffer space installs• Interior (non-ducted installs)

– Northern Climate Spec Tier 2• Buffer space installs

• Northern Climate Spec Tier 2 Interior Installations require exhaust ducting – Left as “TBD” in October– Presented preliminary analysis in December 2011

3

Measure Summary• Measure name: Heat Pump Water Heater• Measure description

– Installation of a heat pump water heater instead of a standard electric tank water heater in single family site built homes in an interior location with exhaust ducts

– Installation shall comply with the Northern Climate Heat Pump Specification for Tier 2 units with exhaust ducting

• Measure spec under development

• Measure type: UES• Today’s Request: Discussion, Review, Decision• Change in measure status: Proposed Provisional• Change in measure savings: n/a• Change in measure cost effectiveness: n/a

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6

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Tier 2: Field Installs

• Current NEEA field study specifies interior installs with exhaust ducting limit airflow to 200 cfm

• Example from one site (1/27/12):– airflow measurements with 12-point duct traverse

Duct Run

  Fitting Diameter (in.) Length (in.)

1 Start 6" 0”

2 Straight Duct 6" 12”

3

6" to 4" Reducer

with damper

6" 8”

4 Straight Duct 4" 10”

5 Exhaust 4"  0”

Airflow MeasurementsTraverse Duct Size CFM

A 4” Damper

Full Open

234B

A 4”

Damper Adjusted

206B

10

Measured Airflow Variation Effects: ATI

• NEEA lab testing of ATI at 67.5F ambient– 375 cfm: full flow, capacity and COP– 200 cfm: 5% capacity and 10% COP reduction– 150 cfm: 11% capacity and 12% COP reduction

60 70 80 90 100 110 120 1300

0.5

1

1.5

2

2.5

3

AirGenerate ATI HPWH Input Power & Output Capacity at Varied Airflows

In Power Full FlowOut Capacity Full FlowLinear (Out Capacity Full Flow)In Power 200 cfmOut Capacity 200 cfmLinear (Out Capacity 200 cfm)In Power 150 cfmOut Capacity 150 cfmLinear (Out Capacity 150 cfm)

Average Tank Temperature (F)

Inpu

t Pow

er a

nd O

utpu

t Cap

acity

(kW

)

60 70 80 90 100 110 120 1300

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

AirGenerate ATI HPWH COP vs Tank Temper-ature at Varied Airflows

Full FlowPoly-nomial (Full Flow)

Average Tank Temperature (F)

COP

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Measured Airflow Variation Effects: Voltex• BPA HPWH lab evaluation observed Voltex compressor performance for 3 flow

scenarios at 67.5F ambient temperature– Full flow: 475 cfm – ⅓ filter area blocked: 372 cfm– ⅔ filter area blocked: 284 cfm Similar, small changes in performance as found with ATI but flow down to 200cfm not

tested

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Overall Savings Estimates

• Impact on house heating + cooling system depends on climate, exhaust airflow, and HVAC system type

• Combining DHW energy savings with heating + cooling impact produces the overall energy savings estimate

• 5 scenarios in 4 climates considered on next slide:– Interior non-ducted (0 cfm flow to outside)– 4 levels of exhaust ducting to outside

• 150, 200, 250, and 300 cfm

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Zonal Resistance Heat (kWh/yr) Electric Resistance Furnace (kWh/yr)CFM PNW HZ1 HZ2 HZ3 CFM PNW HZ1 HZ2 HZ3300 -1283 -1252 -1514 -1764 300 -1464 -1428 -1741 -2036250 -1029 -1003 -1222 -1431 250 -1173 -1143 -1399 -1641200 -839 -817 -1006 -1184 200 -953 -927 -1146 -1349150 -664 -646 -799 -943 150 -751 -730 -906 -1072

0 -1415 -1415 -1479 -1597 0 -1608 -1606 -1688 -1830

Heat Pump HSPF 8.5 (kWh/yr) Gas Furnace AFUE 90 (therms/yr)CFM PNW HZ1 HZ2 HZ3 CFM PNW HZ1 HZ2 HZ3300 -790 -731 -1142 -1542 300 -68 -66 -83 -98250 -617 -572 -888 -1195 250 -54 -53 -66 -78200 -491 -454 -701 -961 200 -46 -44 -56 -67150 -379 -351 -539 -741 150 -35 -33 -42 -51

0 -609 -590 -731 -892 0 -62 -62 -64 -68

Heating System Interaction

• CFM is airflow ducted to outside (“0” corresponds to no ducting)• Negative values are a heating system debit

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Cooling System Interaction• None for houses without cooling system (Zonal Resistance

and Electric Furnace)• Cooling savings for ducted installations nearly negligible but

not so for nonducted ones

• CFM is airflow ducted to outside (“0” corresponds to no ducting)• Positive values are a cooling system benefit

Heat Pump SEER 13 (kWh/yr) Gas Furnace w A/C: SEER 13 (kWh/yr)CFM PNW HZ1 HZ2 HZ3 CFM PNW HZ1 HZ2 HZ3300 20 20 20 20 300 19 19 19 19250 18 18 18 18 250 18 18 18 18200 17 17 17 17 200 17 17 17 17150 16 16 16 16 150 16 16 16 16

0 153 153 153 153 0 152 152 152 152

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Analysis Outputs: Savings Estimates DHW Savings Combined with Heat+Cool Interaction

0 50 100 150 200 250 300 3500

250500750

10001250150017502000

Zonal Resistance Heat (kWh/yr)

PNWHZ1HZ2HZ3

Airflow Ducted to Outside (CFM)

Estim

ated

Sav

ings

(kW

h/yr

)

0 50 100 150 200 250 300 3500

250500750

10001250150017502000

Electric Resistance Furnace (kWh/yr)

PNWHZ1HZ2HZ3

Airflow Ducted to Outside (CFM)

Estim

ated

Sav

ings

(kW

h/yr

)

0 50 100 150 200 250 300 3500

250500750

10001250150017502000

-120

-100

-80

-60

-40

-20

0Gas Furnace 90 AFUE w/ SEER 13 Cooling

PNW

HZ1

HZ2

HZ3

PNW (therms)

HZ1 (therms)

HZ2 (therms)

HZ3 (therms)Airflow Ducted to Outside (CFM)

Estim

ated

Sav

ings

(kW

h/yr

)

Ther

m In

tera

ction

(the

rms/

yr)

0 50 100 150 200 250 300 3500

250500750

10001250150017502000

Heat Pump HSPF 8.5 (kWh/yr)

PNWHZ1HZ2HZ3

Airflow Ducted to Outside (CFM)

Estim

ated

Sav

ings

(kW

h/yr

)

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Analysis Outputs: Combined Savings Tables Zonal Resistance Heat (kWh/yr) Electric Resistance Furnace (kWh/yr)

CFM PNW HZ1 HZ2 HZ3 CFM PNW HZ1 HZ2 HZ3300 662 692 428 197 300 484 520 206 -70250 917 942 722 531 250 776 806 549 327200 994 1016 825 666 200 884 909 690 506150 1145 1163 1009 884 150 1063 1083 907 761

0 538 537 474 374 0 349 350 270 147

Heat Pump HSPF 8.5 (kWh/yr) Gas Furnace AFUE 90 (kWh/yr)CFM PNW HZ1 HZ2 HZ3 CFM PNW HZ1 HZ2 HZ3300 1090 1155 698 284 300 1829 1837 1778 1756250 1263 1314 952 632 250 1839 1847 1791 1771200 1267 1311 1014 744 200 1726 1734 1675 1657150 1352 1387 1149 935 150 1706 1714 1656 1640

0 1407 1433 1248 1071 0 1970 1976 1930 1914

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Measure Cost and Life

• Exhaust venting adder includes materials, labor, and concealing cost (wall board repair)

http://www1.eere.energy.gov/buildings/appliance_standards/residential/pdfs/htgp_finalrule_app8a.pdf

• Total Incremental Cost: $1,810 in 2011 $’s ($1,615 in 2006 $’s)

• Measure Life: 15 years – same as other RTF HPWH and WH measures

Tier 2 Items

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Results with B/C RatiosAnnual Energy Saving (kWh/yr) Tier 1Tier 1 Tier 2

HPWH Location Space Heat Type Small Tank Large Tank Any SizeUnheated Buffer Location Any Heat Type 881 1,811 1,786 Interior Location Gas Heated Home 1,547 2,169 1,726 Interior Location Zonal Electric Heated Home 648 957 994 Interior Location Electric Furnace Heated Home 556 833 884 Interior Location Heat Pump Heated Home 1,189 1,686 1,267

Annual Energy Saving (therms/yr) Tier 1Tier 1 Tier 2HPWH Location Space Heat Type Small Tank Large Tank Any Size

Unheated Buffer Location Any Heat Type (4) (4) (4)

Interior Location Gas Heated Home (38) (52) (46)

TRC B/C Ratio's Tier 1Tier 1 Tier 2HPWH Location Space Heat Type Small Tank Large Tank Any SizeUnheated Buffer Location Any Heat Type 1.0 1.4 1.4 Interior Location Gas Heated Home 1.5 1.4 1.1 Interior Location Zonal Electric Heated Home 0.7 0.7 0.7 Interior Location Electric Furnace Heated Home 0.6 0.6 0.6 Interior Location Heat Pump Heated Home 1.3 1.3 0.9

Capital Cost (2011$'s) Tier 1Tier 1 Tier 2HPWH Location Space Heat Type Small Tank Large Tank Any SizeUnheated Buffer Location Any Heat Type $ 1,009 $ 1,608 $ 1,535 Interior Location Gas Heated Home $ 1,060 $ 1,659 $ 1,810 Interior Location Zonal Electric Heated Home $ 1,060 $ 1,659 $ 1,810 Interior Location Electric Furnace Heated Home $ 1,060 $ 1,659 $ 1,810 Interior Location Heat Pump Heated Home $ 1,060 $ 1,659 $ 1,810

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Call for Participants:Regional HPWH Evaluation Advisory Committee

• Scope 1. RTF sub-committee to study savings, AND 2. regional process and market evaluation

• Co-chaired by – RTF (Tom Eckman), and – NEEA (Dave Kresta)

• Kick-off meeting by end of Feb• Anticipate bi-weekly meetings for several months, then

monthly• Contact Dave Kresta (dkresta@neea.org) if interested in

participating by Feb 17th

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Study Design• Lab tests of Voltex at 200 cfm to confirm performance estimates• Same study design as for other HPWH – here’s the review:• Three primary data collection areas

– Hot Water Consumption– Space Conditioning Interaction (model inputs)– In-field COP

• Study Dates– Site/Participant recruitment

• Program participants through 3/31/2013• Overlap of site selection across data collection areas expected

– Study data collection period: 6/1/2013 – 5/31/2014• Installation of monitoring equipment would occur well before 6/1/2013

– Provisional UES Sunset Date: 12/31/2014

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Study Area: Hot Water Consumption

• Data Collected– Monthly hot water consumption (gallons)

• Sample– 200 sites

• Random/representative sample of program participants

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Study Area: Space Heat Interaction

• Data Collected– Unheated Buffer Space-to-House UA– Unheated Buffer Space estimate of internal gains

(equipment audit)• Sample

– 50 sites

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Study Area: In-Field COP• Data Collected

– Hot water consumption (gallons)– Unheated Buffer Space-to-House UA– Unheated Buffer Space estimate of internal gains (equipment audit)– HPWH energy consumption

• Compressor and Fan• Electric resistance

– ΔT of water delivered– Ambient temperature– For tier 2 (assumes constant speed fan):

• Two-time measurement of – airflow – incoming air temperature

• Sample– 75 sites

• Site selections weighted by program occurrence of HPWH model, installation location, and heating zone.

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Measure Checklist

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Discussion

• Installation specification• Installations with larger airflows?

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Motion to Adopt

“I _________ move that the RTF approve the addition of Tier 2, Ducted Interior Installations to the UES for Heat Pump Water Heaters under provisional status with a sunset date of December 31st, 2014.”