Post on 06-Feb-2018
Ductless or Nearly So
ACI Mid-Atlantic: HVAC Performance Track
October 1, 2012 3:30 PM - 5:00 PM
Linda Wigington, ACI lwigington@affordablecomfort.org
www.affordablecomfort.org
www.thousandhomechallenge.org
1 ACI M-A Conference Pittsburgh Oct 1, 2012
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/
2 ACI M-A Conference Pittsburgh Oct 1, 2012
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
3 ACI M-A Conference Pittsburgh Oct 1, 2012
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
4 ACI M-A Conference Pittsburgh Oct 1, 2012
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
6 ACI M-A Conference Pittsburgh Oct 1, 2012
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
7 ACI M-A Conference Pittsburgh Oct 1, 2012
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
ACI M-A Conference Pittsburgh Oct 1, 2012
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
9 ACI M-A Conference Pittsburgh Oct 1, 2012
Case Studies1 from Pennsylvania & Ohio
10 ACI M-A Conference Pittsburgh Oct 1, 2012
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
11 ACI M-A Conference Pittsburgh Oct 1, 2012
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
ACI M-A Conference Pittsburgh Oct 1, 2012
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)
13 ACI M-A Conference Pittsburgh Oct 1, 2012
Lutz 2012 Cooling Data 78ºF & 74ºF Thermostat Settings
0
1
2
3
4
5
6
7
50
60
70
80
90
100
110
20-
Jun
21-
Jun
22-
Jun
23-
Jun
24-
Jun
25-
Jun
26-
Jun
27-
Jun
28-
Jun
29-
Jun
30-
Jun
1-J
ul
2-J
ul
3-J
ul
4-J
ul
5-J
ul
6-J
ul
7-J
ul
8-J
ul
9-J
ul
10-
Jul
T-Crawl
T-Living
T-Out
kWh
KW
h
Te
mp
Fº
14 ACI M-A Conference Pittsburgh Oct 1, 2012
Implications for Summer Peak Impacts?
Heat Storms? Average Hsg. Stock?
0
1
2
3
4
5
6
7
50
60
70
80
90
100
110
20-
Jun
21-
Jun
22-
Jun
23-
Jun
24-
Jun
25-
Jun
26-
Jun
27-
Jun
28-
Jun
29-
Jun
30-
Jun
1-J
ul
2-J
ul
3-J
ul
4-J
ul
5-J
ul
6-J
ul
7-J
ul
8-J
ul
9-J
ul
10
-Ju
l
T-Crawl
T-Living
T-Out
kWh
KW
h
Te
mp
Fº
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
ACI M-A Conference Pittsburgh Oct 1, 2012
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
16 ACI M-A Conference Pittsburgh Oct 1, 2012
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
18 ACI M-A Conference Pittsburgh Oct 1, 2012
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
19 ACI M-A Conference Pittsburgh Oct 1, 2012
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
21 ACI M-A Conference Pittsburgh Oct 1, 2012
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
22 ACI M-A Conference Pittsburgh Oct 1, 2012
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
23 ACI M-A Conference Pittsburgh Oct 1, 2012
Previous Propane use 1,500-1,800 gal/yr. 2009-2010 ~650 gal; 2011-12 ~300 gal
0.00
2.00
4.00
6.00
8.00
10.00
12.00
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
24 ACI M-A Conference Pittsburgh Oct 1, 2012
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
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
16,000
18,000
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!
29 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!
The bad news is:
– Occupants can have a huge impact on maximizing benefits from ductless heat pumps!
30 ACI M-A Conference Pittsburgh Oct 1, 2012
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
31 ACI M-A Conference Pittsburgh Oct 1, 2012
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
ACI M-A Conference Pittsburgh Oct 1, 2012 32
Feedback, Case Studies, & Projects Welcome!
Linda Wigington 724-852-3085 lwigington@affordablecomfort.org Intro to the Thousand Home Challenge Webinar www.1000HomeChallenge.org THC Threshold Calculator Deep Energy Reductions Resources DER Case Studies ETC THC Webinars
33 ACI M-A Conference Pittsburgh Oct 1, 2012
Additional Case Study Not Included in Presentation Due to
Time Constraints
34 ACI M-A Conference Pittsburgh Oct 1, 2012
John Morgan Deep Energy Reduction (jmrrpress@gmail.com)
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
36 ACI M-A Conference Pittsburgh Oct 1, 2012
“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)
37 ACI M-A Conference Pittsburgh Oct 1, 2012
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
38 ACI M-A Conference Pittsburgh Oct 1, 2012