Transcript Heat Pump Research Project Sponsored by the Heat Pump Working Group June 7, 2005

Heat Pump Research Project
Sponsored by the
Heat Pump Working Group
June 7, 2005
Project Goals
1. Assess energy use and savings from heat pumps
installed under C&RD/ConAug and EWEB.
2. Assess base case installation practices.
3. Assess heat pump performance under laboratory
conditions to identify optimal settings.
4. Assess the general approach of installers to
control, sizing and performance issues, and of
manufacturers to new technologies, etc.
Billing Results
EWEB Billing Analysis Results
C&RD / ConAug Billing Analysis Results
Revised Results
Previous Results
ite
s
Al
lS
Zo
na
l
w/
oC
AC
FA
F
w/
CA
C
FA
F
um
p
9,000
8,000
7,000
6,000
5,000
4,000
3,000
2,000
1,000
0
He
at
P
kWh/year
All Cases NAC Saved with 90% C.L.
Billing Analysis Results by System Type
SF Sqft with 90% C.L. by Systype,
n= 470
9,000
8,000
7,000
6,000
5,000
4,000
3,000
2,000
1,000
0
3,000
kWh/year
2,500
2,000
1,500
1,000
500
Al
lC
as
es
al
Zo
n
tP
um
p
He
a
CA
C
w/
o
FA
F
w/
CA
C
FA
F
ite
s
Al
lS
Zo
na
l
w/
oC
AC
FA
F
w/
CA
C
FA
F
um
p
0
He
at
P
kWh/year
All Cases NAC Saved with 90% C.L.
Billing Analysis Results by Building Type
9,000
8,000
7,000
6,000
5,000
4,000
3,000
2,000
1,000
0
C&RD MH Cases NAC Saved by System
Type with 90% C.L., n= 124
kWh/year
kWh/year
C&RD SF Cases NAC Saved by System
Type with 90% C.L., n= 549
10,000
9,000
8,000
7,000
6,000
5,000
4,000
3,000
2,000
1,000
0
Billing Analysis Results by Vintage
MH NAC Saved with 90% C.L.
by Vintage Bin, n= 114
7,000
5,000
6,000
kWh/year
6,000
4,000
3,000
2,000
5,000
4,000
3,000
2,000
0
Legend:
1 Pre 1981
2 1981 – 1994
3 Post 94
Al
lC
&R
D
0
3
1,000
2
1,000
1
kWh/year
SF NAC Saved with 90% C.L.
by Vintage Bin, n= 523
Realization Rates by Program Year Base
Prog
Year
20022003
Area
n
Gross
NAC
kWh/yr
Net NAC
kWh/yr
Zone 1
90%
CI
Anticipated
kWh/yr
RR
518
4,698
4,584
490
7,288 63%
Zone 3
318
3,795
3,681
590
6,815
54%
All
C&RD
836
4,354
4,240
382
7,108
60%
Realization Rates for C&RD Calculator, Initial
C&RD
kWh
2003
Zone 1
Zone 2
2005
Zone 1
Zone 2
Billing Analysis
Unadjusted
R.Rate
kWh
Adjusted
R.Rate
kWh
6563
6464
3838
3432
0.585
0.531
4359
3681
0.664
0.569
5478
5456
3838
3432
0.701
0.629
4359
3681
0.796
0.675
Realization Rates, Revised
Realization Rates
Sector
Year
Manufactured Homes
2003
2005
Single Family Homes
2003
2005
Measure
FAFw/ AC FAFw/oACHP
66%
71%
70%
118%
60%
70%
69%
83%
UpgradeZonal
218%
215%
489%
84%
254%
129%
kWh Savings estimates
Savings: C&RD
Sector
Year
Manufactured Homes
2003
2005
Single Family Homes
2003
2005
Measure
FAFw/ AC FAFw/oACHP Upgrade
Zonal
5613
6654
1773
5289
4005
1798
8054
7010
976
3423
7035
5905
1879
2243
Savings: Billing Analysis
Measure
Sector
Year
FAFw/ AC FAFw/oACHP Upgrade
Zonal
Manufactured Homes
2003
3692
4713
3860
Single Family Homes
2003
4858
4880
4773
2890
Laboratory Results
HSPF: Fixed Orifice & TXV
Purdue FEO, Zone 4 (blue), Zone 6 (red)
Purdue TXV, Zone 4 (blue), Zone 6 (red)
10
10
9
130
100
8
100
130
70
70
130
100
130
100
70
70
7
100
70
130
100
130
70
70
130
7
130
70
100
130
100
70
8
100
6
130
100
70
100
70
130
6
500
1000
1500
Air Flow Rate (scfm)
2000
500
10
1000
1500
Air Flow Rate (scfm)
2000
10
9
8
1700
1300
1300
1700
1700
800
1300
800
1300
1700
800
800
1700
1300
1700
800
1300
7
800
HSPF
9
HSPF
100
130
70
HSPF
HSPF
9
1300
1300
1700
8
1300
1700
800
1300
1700
800
7
1700
1300
800
800
800
6
1300
1700
1700
800
6
60
80
100
Charge (%)
120
140
60
80
100
Charge (%)
120
140
Summary of Lab Results
• Impacts of refrigerant charge minimal except at very reduced
levels (70% of specification)
• Impacts of air flow also limited to cases with very low air
handler flow (less than 300 CFM/ton).
• Low air flow appears to occur in about 25% of “base case”
installation practice
• TXV improves overall performance but has minimal impacts
on the effects of low charge and low air flow
• Cd higher than modeling assumptions for fixed orifice, lower
than assumption for TXV
• Defrost degradation factors largely stable at values near the
modeled and manufacturer’s assumptions.
Field Data Summary
Field Study Overview
• 160 field sites in 4 regions (Central Oregon, Kitsap
Peninsula, Clark Co., Yakima/Walla Walla) started
September 2004
• “Base case” sites, chosen at random to represent nonPTCS installations
– Combine field findings with billing data to recalibrate
performance assumptions used in RTF calculations
• On-site review consists of two visits
– Duct/house review (complete)
– Heat pump review by service tech. (110 sites now in,
additional 15 sites expected)
Site Selection
• Sites selected via random telephone dial to have airsource heat pump and be within appropriate utility
territory
• Sites might have basements/interior ducts
• Clark County chosen vs. Portland because of paucity
of HPs in PDX Pacific Power svc territory
– Clark actually has HP inspection program so non-typical vs
other areas
Key Audit Outputs
(house/duct)
• House heat loss rate (UA)
– Integral part of modeling house performance vs bills
– Includes infiltration component (blower door test)
• System airflow (CFM)
– System capacity & efficiency
• Duct system insulation and leakage
– System operating pressures also measured
• Duct leakage fraction (%)
– Effect on overall delivery efficiency/energy use
• Homeowner interaction with system (via survey)
Key Audit Outputs
(heat pump review)
• HP control strategy
– Indoor thermostat type, setting and staging
– Outdoor thermostat presence, setting and operation
– Compressor low ambient cut out
• Refrigerant charge level
.4
.3
.2
UA per sq.ft.
.5
.6
Building Characteristics – Heat Loss Rate
Pre-76
76-80
80-86
86-92
92-2000
2000+
.25
Blower Door Results
0
.05
.1
.15
.2
– Median ACH50 is 7.6
for 149 clean cases;
mean is 8.3
– This converts to
median ACHnat of 0.38
– Highest ACH50 19.0
– Lowest ACH50 1.6
0
5
10
ach50
15
20
0
5
10
15
20
Blower Door Results by Vintage Bin
Pre-76
76-80
80-86
86-92
92-2000
2000+
.3
.2
.1
0
Leakage fraction
.4
.5
Duct Leakage Fraction (all sites)
Return leak f raction
Nonzero RLF omitted
Supply leak f raction
Duct Leakage by Vintage Bin
Return Side
.2
0
0
.1
.1
.2
.3
Return leak fraction
.3
.4
.4
.5
Supply Side
Pre-76
76-80
80-86
86-92
92-2000
2000+
Pre-76
76-80
80-86
86-92
92-2000
2000+
Supply vs. Return Leakage
Supply vs. Return Duct Leakage Fraction
Supply Leakage Fraction
0.5
0.4
0.3
0.2
0.1
0.0
0.0
0.1
0.2
0.3
Return Leakage Fraction
0.4
0.5
System Fan Flow
• Median flow is 340
CFM/ton (n=126)
• Lower quartile is <=292
CFM/ton
• ECM cases (n=21*),
median flow is 338
CFM/ton
*final # will be larger
.1
0
.05
Fraction
.15
.2
Airflow Distribution
200
300
400
Indoor unit CFM/ton
500
200
300
400
500
System airflow by size of outdoor unit
1.5
2
2.5
3
Tons
3.5
4
5
Refrigerant Charge Evaluation
• Review predominantly done
in swing seasons
– Heating season evaluation
combined tech’s review of
operating pressures and
sensible split in context of
ambient temp., system
airflow, coil match
• About 1/3 of systems
evaluated in cooling only
mode or in addition to
heating mode
– Superheat/subcooling
evaluation
Charge Results
• 60% of cases evaluated
as having correct charge
• 28% of cases evaluated
as being overcharged
• 10% of cases evaluated
as being undercharged
– 2 had serious leaks (no
refrigerant)
Refrigerant Charge Digest
• Over/undercharge amounts likely under-reported vs
weigh-in approach
• However, cases of severe undercharge were very
limited
• ½ of overcharged cases had an accumulator
• 2/3 of remaining overcharged cases were units with
Trane compressors or scroll compressors
Heat Pump Efficiency
9
8.5
7
7.5
8
HSPF
7
7.5
8
HSPF
8.5
9
9.5
HSPF by Equipment Size
9.5
HSPF by Region
Bend
Clark
Kitsap
Y akima
1.5
2
2.5
3
3.5
4
5
HVAC Usage
(from median low bill analysis of 124 bills)
Cooling - Annual kWh
0
0
2,000
10,000
4,000
20,000
6,000
8,000
30,000
Heating - Annual kWh
Bend
Clark
Kitsap
Y akima
Bend
Clark
Kitsap
Y akima
Normalized Heating Load
by Vintage and Region
Total Usage - Annual kWh/sf
0
0
2
10,000
4
20,000
6
30,000
8
40,000
10
50,000
Heating - Annual kWh/sf
Pre-76
76-80
80-86
86-92
92-2000
2000+
Bend
Clark
Kitsap
Y akima
Normalized Heating Usage
25
Impact of wood – Annual kWh/sf
Percentage of Sample Using Wood
No
Wood
Wood
Total
Bend
64.86
35.14
100
Clark
59.38
40.63
100
Kitsap
36.84
63.16
100
Yakima
66.67
33.33
100
Total
56.85
43.15
100
0
5
10
15
20
Region
No Wood
Wood
Modeled Duct Efficiency
(efficiency of 1 is perfect ducts)
.8
.7
.6
.5
.5
.6
.7
.8
.9
By Vintage
.9
By Region
Bend
Clark
Kitsap
Y akima
Pre-76
76-80
80-86
86-92
92-2000
2000+
Duct Insulation
R-Value of Supply Ducts
0
0
50
5
100
10
150
15
200
20
250
Supply vs. Return UA
0
20
40
60
retua
80
100
Pre-76
76-80
80-86
86-92
92-2000
2000+
TXV Summary (Outdoor Unit)
80%
67%
70%
60%
61%
50%
50%
35%
40%
32%
30%
20%
10%
0%
overall
Bend
Clark
Kitsap
Yak/WW
TXV Summary (Indoor Unit)
90%
81%
80%
70%
70%
64%
63%
60%
50%
38%
40%
30%
20%
10%
0%
overall
Bend
Clark
Kitsap
Yak/WW
Thermostat/Homeowner Interaction
• ~80% of systems have programmable stats…
• ~1/3 of occupants say they understand their
thermostat and/or like how it keeps their house
comfortable
• ~1/3 say they tolerate their thermostat (but wish they
understood it better)
• ~1/3 have thrown up their hands and use the HOLD
feature
Controls: Indoor Thermostat
• 78% programmable
• Median heating
setpoint: 70 F
• Median setback: 65 F
• 55% of systems with
setback > 5 F
– Estimated 75% of
programmable stats have
adaptive recovery
Controls: Outdoor Thermostat
• About 35% of sites visited
had an operating ODT (75%
of Clark sites have ODT)
• Average setting 40° F
• About 2/3 of sites without
ODTs had the extra wires
needed to install one
without fishing new wire
• Only 15% of systems had
elements on in Stage 1
heating
– Median on-time 5 minutes
Market Actor Interviews
HVAC Installer Interviews
(detailed results)
• 32 shops throughout region in urban, suburban, rural areas (29
full interviews)
• Shops range from 2 trucks to 30, median of 6
• Median 50% new construction
• Participants install all major (and some secondary) brands of
equipment
• Almost all participants report use of non-intuitive heat pump
and duct sizing tools (Manual J, Manual D, etc.)
• Wide range of experience with utility, state, national
incentive/marketing campaigns and installation procedures
Technician Certification
NATE-Certified Technicians
Percentage of Technicians
100
80
60
40
20
0
0
5
10
15
20
25
Percentage of Respondents
30
35
Installer System Sizing Criteria
Typical Sizing Priority
Sizing Priority When Loads Differ
Heat
Heat
Co o l
Co o l
Bo th
0
10
20
30
40
Perce nta ge of R es ponde nts
50
60
0
10
20
30
40
Perce nta ge of R es ponde nts
50
60
Characteristics of Efficient Line
SEER of Efficient Line
HSPF of Efficient Line
12
20
11
18
17
16
SEER
HSPF
10.5
10
9.85
9
9.5
15
14
14
13
12
12
8
11
8.0
10
8
7
0
10
20
30
40
50
Percentage of Respondents
60
70
80
0
10
20
30
40
50
Percentage of Respondents
60
70
80
Installation Characteristics - TXVs
TXV on the Indoor Coil
TXV on the Outdoor Coil
50
Pe rcentage of Respondents
Percentage of Respondents
50
40
30
20
10
40
30
20
10
0
0
0%
20%
40%
60%
80%
Percentage of Heat Pump Ins tallations
100%
0%
20%
40%
60%
80%
Perce nta ge of He at Pump Ins ta lla tions
100%
Availability/cost of Outdoor Unit TXV
Factory Equipped TXV
Cost of Field-Installed TXV
500
Estimated Cost ($/Unit)
Percentage of Units
100
80
60
40
20
400
300
200
100
0
0
0
10
20
30
40
Percentage of Respondents
50
60
0
10
20
30
40
Percentage of Respondents
50
60
Acceptance of TXV Technology
General Opinion of TXV Technology
Un su re/Do n ' t Kn o w
Po sitiv e
Neu tral
Neg ativ e
0
20
40
60
Pe rcentage of R es ponde nts
80
100
Outdoor Thermostat/Low Ambient Cutout
Low Ambient Cut Out Enabled?
Outdoor Thermostats Typically Installed?
S eld o m
M os t re s pondents s e t a t 40° F
Yes
Often
No
No
0
20
40
60
Perce nta ge of R es ponde nts
80
100
0
20
40
60
80
Perce nta ge of R es ponde nts
All “often” cases in
TriCities/Yakima
All “seldom” cases as above or
Mid-Columbia
100
Installation Characteristics – Aux Heat
Element wired in first stage heating?
Seldom
Often
Never
0
10
20
30
40
50
60
70
80
Percentage of Respondents
Out of 7 cases answering “seldom” or “often”, 5 In Zone 2 (E Wash or Boise)
Installer Target System Airflow
Preferred Airflow per Ton
Airflow Per Ton
450
400
350
300
0
10
20
30
40
50
Percentage of Respondents
60
70
80
R410a
Pe rce ntage of Insta lla tions
Heat Pumps Installed with R410a
General Opinion of R410a
100%
Un imp ressed
80%
To o n ew
To o ex p en siv e
60%
Mo re lab o r
Lik e it
40%
Hig h er p ressu re
Hig h er d u ct temp
20%
Gu ard ed ly o p timistic
0%
Ev acu atio n co n cern s
0
5
10
15
Pe rcentage of R es ponde nts
20
25
0
5
10
15
Pe rce ntage of R es pondents
20
25
PTCS
Familiar with PTCS specifications?
Percentage of PTCS-Certified Installations
76 to 100
Yes
51 to 75
26 to 50
No
1 to 25
0
10
20
30
40
50
Percentage of Respondents
60
70
0
10
20
30
40
50
Percentage of Respondents
60
70
Familiarity With Third Party Charge Checking
Familiar with CheckMe/ACRx/EEnalysis Programs
Number of Check Me Certifications
76 to 100
Very
51 to 75
Somewhat
26 to 50
No
1 to 25
0
10
20
30
40
50
Percentage of Respondents
60
70
0
10
20
30
40
50
Percentage of Respondents
60
70
Acceptance of Third Party Mechanisms
Disadvantages of CheckMe and Similar Programs
Advantages of CheckMe and Similar Programs
To o mu ch p ap erwo rk
Imp ro v ed d ata
Req u ires 2 site v isits
Aid s ' u p sellin g '
Hard to sell
0
20
40
60
Pe rcentage of R es ponde nts
80
100
0
20
40
60
Pe rcentage of R e s pondents
80
100
Energy Star
Familiarity with Energy Star HP Efficiency Requirements
Very aware
So mewh at aware
Nev er h eard o f
0
10
20
30
Pe rc enta ge of R es ponde nts
40
50
Penetration of Incentives & Tax Credits
Perce nta ge of Re spondents
Installations Receiving Tax Credits or Incentives
3 5 .0
3 0 .0
2 5 .0
2 0 .0
1 5 .0
1 0 .0
5 .0
0 .0
1 0 % 2 0 % 3 0 % 4 0 % 5 0 % 6 0 % 7 0 % 8 0 % 9 0 %1 0 0 %
Pe rc enta ge of Ins ta llations
Marketing Impacts
Do Incentives Impact Bottom Line?
Does lower ETO requirement make a difference in sales?
Yes
Yes
No
No
0
20
40
60
Pe rcentage of R es ponde nts
80
100
0
20
40
60
Perc enta ge of R e s pondents
80
100
Challenges in Explaining
Tax Credits/Incentives to Customers
Too complicated
Not difficult
Acces s to information
0
20
40
60
Percentage of R es pondents
80
100
Client Priorities
Most Important Factor to Customer
B oth
Operating C os t
Firs t C os t
0
20
40
60
Percentage of R es pondents
80
100
Comments on Thermostats
To u ch screen s mu ch b etter
Difficu lt to p ro g ram
0
10
20
30
40
50
60
70
Pe rcenta ge of R e s pondents
80
90
100
Perceived Trends
Perceived Trends in Consumer Interest in Heat Pumps
In cen tiv es
Imp ro v in g tech n o lo g y
F u el selectio n
F u el co st
Co n su mer awaren ess
0
10
20
30
Perc enta ge of R es ponde nts
40
50