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Ductless or Nearly So

ACI Mid-Atlantic: HVAC Performance Track

October 1, 2012 3:30 PM - 5:00 PM

Linda Wigington, ACI [email protected]

www.affordablecomfort.org

www.thousandhomechallenge.org

1 ACI M-A Conference Pittsburgh Oct 1, 2012

mailto:[email protected]

http://www.affordablecomfort.org/

http://www.thousandhomechallenge.org/

Access to Resources Pacific Northwest

www.goingductless.com

www.nwductless.com

Thousand Home Challenge Planning Resource http://thousandhomechallenge.com/resources http://thousandhomechallenge.com/thc-webinars-ductless-heat-pumps

Webinars: DHP & Mini-splits Cost of Home Heating Access to Resources: Ductless Heat Pumps

Home Energy Pros Thousand Home Challenge Group http://homeenergypros.lbl.gov/

gov/


http://www.goingductless.com/

http://www.nwductless.com/

http://thousandhomechallenge.com/resources




http://thousandhomechallenge.com/thc-webinars-ductless-heat-pumps










http://homeenergypros.lbl.gov/

http://homeenergypros.lbl.gov/

Definitions: This Session

Ductless Heat Pump (DHP) Linda • Single inside head, single outdoor unit • Not ducted Nearly So (Mini-split) Dave • May have minimal ducting • Includes DHP

In all cases: Inverter driven DHP suitable for cold climates Session not addressing multi-head systems


Conversions (Btu:Btu)

Site Energy – not accounting for system efficiency differences

• All numbers used are site energy, not source!

• 30 kWh = ~1 therm

• 7,500 kWh = ~25 MMBtu

• 7,500 kWh ($750) = ~250 therms ($250)

• 7,500 kWh = ~180 gallons #2 oil ($720)

• 2,000 kWh = ~63 therms


Ductless Heat Pump (DHP) Not New – But High Performance is Game Changer

5 Photos: Jeff Pratt

• Inverter driven; variable speed

• Output & performance over huge temperature range

• Cold climates applications

• No electric resistance

• Efficiency (COP) higher at partial loads

NW Field Performance Studies

3,500 kWh Reduction/

(installed in homes w/electric resistance heat)

Inside head

Outside Unit

ACI M-A Conference Pittsburgh Oct 1, 2012

Ductless Heat Pumps: Applications

• Much broader than often advocated

• Use in transition (w/either central or point source)

• Sufficient (go solo)

• Potentially less expensive & simpler to install, maintain, & use than alternatives

• Minimize complexity – duct pressure effects, combustion safety

• Can get cooing only, or both heating & cooling


Pacific NW Leading the Way in US

• Regional collaboration – BPA, NEEA, utilities, & other stakeholders

• Focus: offset electric resistance heating • 2 field studies; w/lab & sub metering (Ecotope) • http://www.bpa.gov/energy/n/doc/BPA-

Report_Ductless-Heat-Pump-June2009.pdf • Set technical standards • Train & approve contractors • Incentives • 15,000+ DHPs installed


http://www.bpa.gov/energy/n/doc/BPA-Report_Ductless-Heat-Pump-June2009.pdf










NW DHP Study 1 (by Pre-Heating Use)

8

First of two Pacific Northwest field studies; 2nd study – Starting with forced air homes, significantly higher savings than homes starting with zoned electric heating

15,000 kWh =~50 MMBtu or 500 therms Slide credit – Bob Davis Davis, Ecotope

Single zone ductless systems installed in NW homes heated with zonal electric heat


NW Preliminary Results 2nd Study: DHPs in Homes w Forced-Air Electric

• Greater average savings than 1st NW study (offsetting duct losses: additional +25% savings)

• 5,500 kWh/yr average

• Occupant control strategy has a big impact on savings

• Double the savings – DHP primary vs. secondary


Case Studies1 from Pennsylvania & Ohio


1 1000 Home Challenge Status (www.1000HomeChallenge.org) • Ward Lutz & Wayne Mackey both officially meet the 1000

Home Challenge. & since acceptance have gone forward to achieve net zero energy (site energy); full case studies are posted on the THC website.

• Jefferson Rental is on the track to meeting THC in November 2012

• The Western PA Farmhouse does not meet the THC • Lippencott & John Morgan homes both meet their THC

threshold; THC applications are in progress

Lutz Project

• Urbana, Ohio • 5,400 HDD • 576 Ft2

• PRE: Electric space heater; 50-55° F • Feb 2010: One 9,000 Btu/hr. ductless heat pump 60-65° F • Superinsulated in 2008 – 6 sides, R-40 exterior foam walls • DHP Experiment: Outside unit in buffered crawl space (may void warranty)

2011-12 RESULTS Heating: 435 kWh (132 kWh in January) Cooling: .5 to 6 kWh/day @ 90 - 105°F ambient Household Energy: Net exporting w/ 3.5 KW PV array Case Study - www.ThousandHomeChallenge.org


Data! 11/22/11-2/2/2012

12

Heating Energy (kWh/day)

House Temp

Outside Temp

Ductless Heat Pump use from 11/22 to 2/22 = 348 kWh (~12 therms)

Crawl Space Temp


0 20 40 60 80 100 120 140

Nov-11

Dec-11

Jan-12

Feb-12

Mar-12

Apr-12

Ward Lutz (Urbana, OH) DHP kWh per Month (60°F)

2011-12 Heating Use: 435 kWh

<.5 to 4.5 kWh/day for DHP heating ($.05 to $.45/day @ $.10/kWh)


Lutz 2012 Cooling Data 78ºF & 74ºF Thermostat Settings

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T-Crawl

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Implications for Summer Peak Impacts?

Heat Storms? Average Hsg. Stock?

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100º weather! 1-6 kWh/day for cooling

Additional data posted: http://homeenergypros.lbl.gov/group/1000homechallenge/forum/topics/hot-weather-ductless-heat-pump-performance

15


http://homeenergypros.lbl.gov/group/1000homechallenge/forum/topics/hot-weather-ductless-heat-pump-performance











Mackey Project

• Chambersburg, PA • 5,343 HDD • 2,500 2 2-story, partially finished basement • Well insulated, 1,100 CFM 50; R5 windows • PRE: Forced Air Heat Pump; POST Aug 2011: (2) 9,000 Btu/hr RLS Fujitsu DHP • HEATING & COOLING RESULTS (since Dec 1, 2011) • 1st Floor DHP 1,105 kWh; $85.981 • 2nd Floor DHP 369 kWh; $31.241 • Central system (high-end Bryant HP) not needed at all • Very satisfied occupants (increased control over comfort) • Home was low energy, now exports electricity with 7.5 KW PV; EV too! 1Actual cost zero, due to PV production Case Study - www.ThousandHomeChallenge.org


Cost Per MMBtu (refer to handout1)

17

1Cost of energy shown does not reflect current regional prices; handout closer to actual. W PA electricity – ½ cost shown. Editable document: http://thousandhomechallenge.com/thc-webinars-ductless-heat-pumps ACI M-A Conference Pittsburgh Oct 1, 2012











720 Ft2 Finished Floor Area ~5,300 Heating Degree Days Attic ~R 40 cellulose (recent) ; Walls: blown-in fiberglass (years ago) Windows double-pane recent replacement (<10 years ago) Electric cooking; heat pump water heater in basement Unconditioned basement, crawl space under bath/kitchen; partial insulation (in progress) Panasonic EOV/ ceiling radiant panel in bathroom

Modest Rental Jefferson, PA


2010-11 – Direct vent fireplace & electric space heaters NOTE: Little temperature control with fireplace or electric heaters 2011-12 – Ductless heat pump installed Nov 20, 2011 NOTE: Winter thermostat set point: (80°F); average ceiling ~ 75°F @ 4 ft. from floor Summer thermostat set point: 68°F

Fireplace no longer In use


Impact of 9,000 Btu/hr. RLS Fujitsu DHP (Pre & Post Energy Use in kWh (Site))

0 5,000 10,000 15,000 20,000 25,000

PRE BY ENERGY SOURCE11/28/10 - 10/02/2011

POST BY END-USE11/20/11 - 9/30/12

POST ALL ELECTRICITY11/20/11 - 9/30/12

Natural GasDV Fireplace(482 therms)

Total Household Electricity

Household Electricity (minus DHP)

DHP ElectricityHeating & Cooling

NOTE: Pre-use characterized by overheating with gas & electric space heaters 20 ACI M-A Conference Pittsburgh Oct 1, 2012

Heating/Cooling Energy Use & Cost 11-20-2011 to 9-15-2012 DHP sub metered

T Stat kWh ~ Cost

DHP Heating 11-20-11 to 5-12-2012

80º 2,097 $210

Other Heating (estimate) Electric Res. Space Heaters

600 $60

DHP Cooling 68º 232 $23


In post period with the ductless heat pump, all natural gas use was eliminated (service was disconnected to eliminate $12.00 monthly service charge). In addition, annual electricity use was lowered. Post period was warmer (both summer & winter) with increased occupancy (1 to 3) for a 6 week period. Electricity cost: ~$.10/kWh

Western Pennsylvania Farmhouse

Claysville, PA 5,500 HDD Built ~1850; 3,000 ft2

Free gas until 2000 Propane furnace, dryer 1,500 gal/yr. initially Fix propane leaks, partially air sealed & insulated Air Leakage: Pre - ~7,700 CFM50 Post 5,000 CFM50

Goal: • Offset propane heat & dryer • Shift to electricity without increasing

annual electricity use


11/18/2011: 15,000 Btu/hr. ductless heat pump in dining room; 9,000 Btu/hr. DHP upstairs bedroom (primarily for cooling)

Propane furnace for faster warm-up & to carry load in coldest weather; central AC used only in hottest weather, after several days; switched to electric dryer – 12/2011

RESULTS • 2,000 kWh/yr htg by DHPs; ~350 gal propane reduction;

1,000 kWh/yr cooling • Annual electricity use up 259 kWh/yr (11,458 kWh/yr);

Electric dryer 500 kWh; no net increase DHP alone • Improvement in $ & air temp, winter comfort not

adequate yet; air movement noticeable at times

2001: 80,000 Btu propane furnace

Outdoor unit (DHP)

Indoor unit – Ductless heat pump; (high on wall)

Sub meters, read bi-weekly


Previous Propane use 1,500-1,800 gal/yr. 2009-2010 ~650 gal; 2011-12 ~300 gal

0.00

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4.00

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14.00

Gal/Day/Propane

Gal/Day/Propane

Fixed gas leaks; 2nd floor insulation & air sealing Deep T-stat set

point reduction Jan 2011 Nov 15 2011 Added 2 DHP Set point up to 60-65°F


Heating Energy (in kWh/Yr)

0 5,000 10,000 15,000 20,000 25,000 30,000 35,000 40,000

2 DuctlessHeat Pumps

(InstalledNov,18, 2011)

300 gal/yr

Post 2nd FloorIns & Air Sealing

Seal gas leaks650 gal/yr

Pre 2nd FloorIns & Air Sealing

1,300 gal/yr

Propane (in kWh)

Duct Heat Pump (kWh)

2 DHP Payback ($5,500 Install) ~6 years DHP Heating Use: 2,000 kWh; $200

30,000 kWh = ~100 MMBtu or 1000 Therms 25 ACI M-A Conference Pittsburgh Oct 1, 2012

Question & Opportunity (slide added since Oct 1, 2012 presentation)

How to offset more propane by using upstairs DHP to heat downstairs?1

ACI M-A Conference Pittsburgh Oct 1, 2012 26

DHP Heating - kWh

DHP Cooling - kWh

DHP Total – kWh/Cost2

RLS 15 DHP Downstairs

1,670 482 2,152 kWh ~$205

RLS 9 DHP Upstairs

402 553 955 kWh ~$95

DHP TOTAL kWh/$

2,072 kWh ~$200

1,035 kWh ~$100

4,107 kWh ~$300

1 Follow discussion: http://homeenergypros.lbl.gov/group/1000homechallenge/forum/topics/panasonic-whisper-

green-w-ductless-heat-pump?page=1&commentId=6069565%3AComment%3A97476&x=1#6069565Comment97476

2 Assuming ~.$10/kWh

http://homeenergypros.lbl.gov/group/1000homechallenge/forum/topics/panasonic-whisper-green-w-ductless-heat-pump?page=1&commentId=6069565%3AComment%3A97476&x=1














Lippencott House – SW PA 2011-12 Heating • 690 kWh ($69) – DHP

heating + ~9 gal of oil • 65°F set point

(upstairs) • 50-55°F downstairs • Work/living upstairs • Previous 65-75 gal oil

70 year-old home 5,400 HDD 1,000 Ft2; Insulated; 750 CFM50

2012 Summer Cooling DHP 149 kWh ($15) 74°-76°F set point House temperature uniform (both floors)

27 ACI M-A Conference Pittsburgh Oct 1, 2012 Toyatomi DV Oil Heater

Household Energy Use/Yr. Over time (Lippencott House (converted to kWh; 1 gal oil = ~40 kWh)

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

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2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012

kWh (electricity)

kWh (oil)

Oil Space Heater 50-55°

Oil Furnace 50-55°

Approx. 300 Gallons Oil/Yr.

DHP 60-65°

Each year is from April 15-April 15 28 ACI M-A Conference Pittsburgh Oct 1, 2012

Good News – Bad News

The good news is

– Occupants can have a huge impact on maximizing benefits from ductless heat pumps!


Good News – Bad News

The good news is:


The bad news is:



Occupant Interactions

• Using as primary source of heating/cooling increases benefits (PNW study with central heating: 2 to 1 difference)

• Long run time can give misperception of high energy use

• Rapid feedback (re operating cost) can impact occupant preference of DHP over other space conditioning options

• No set-back, continuous operation increases consistent temperatures throughout house


My Conclusions (slide added since Oct 1, 2012 presentation)

1) DHPs offer significant opportunity offset site & source energy in a range of homes (vintage, energy intensity, & climate).

2) Annual savings is greater when offsetting a) Higher priced energy sources (oil, propane, & electric resistance)

b) Inefficient HVAC systems or building enclosures

3) DHPs help make deep reductions/NZE (site energy) more attainable


Feedback, Case Studies, & Projects Welcome!

Linda Wigington 724-852-3085 [email protected] Intro to the Thousand Home Challenge Webinar www.1000HomeChallenge.org THC Threshold Calculator Deep Energy Reductions Resources DER Case Studies ETC THC Webinars


http://www.1000homechallenge.org/

Additional Case Study Not Included in Presentation Due to

Time Constraints


John Morgan Deep Energy Reduction ([email protected])

Ravens Rocks, Beallsville, OH 35

Rev 10-01-2012 35 ACI M-A Conference Pittsburgh Oct 1, 2012

130-Year-Old Farmhouse Project Summary

Previous Efforts: • Mineral wool insulation: 5" walls cavities; R-45 attic

• Owner-built storm windows (extra pane added)

• Basement partial exterior insulation, unheated

• Propane cooking, water heating, & cast iron boiler

• Home office

• 2009 embarked on creative comfort (temperature in 50°F’s; previously set on 60°F)

– 784 ft2 main floor heated

– 392 ft2 insulated second floor bedrooms unheated


“It is not what you have that counts, but rather, what you can afford to do without.”

Replacing this with a ductless heat pump reduced heating site energy by 89%! (~200 gallons of propane)


January 2011 Replaced propane boiler with Fujitsu 9,000 BTU ductless heat pump

• DHP is sub-metered

• DHP T-stat: Daytime 60° F; night - completely off

• Actual office temperature 55°-58° F

• Rest of living area 5 to 10 degrees colder (depending on outside conditions); do not heat 2nd floor or basement

• Office temperature higher in 2011 than previous year (2009-10)

• Reductions due to: 1) more efficient system; 2) increased ability to zone/control heat

• If goal was even temperature throughout house; system would have been left on 24/7 – same thermostat set-point


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