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1
Proposed Changes to the RTF’s Heat Pump Deemed Savings and Cost-
Effectiveness
Draft 6th Plan Assumptions
April 7, 2009
2
Background
• Bonneville requested RTF Review of 6th Plan Heat Pump Deemed Savings and Cost-Effectiveness Assumptions
• Are More Upgrades Cost-Effective with Higher Avoided Costs?
• With A Revised Base Case Assumption for Conversion of Forced-Air Furnace Systems to Heat Pumps, Which Measures are Cost-Effective?
3
Existing Deemed Savings for Heat Pump Upgrades & Conversions
0
2,000
4,000
6,000
8,000
10,000
12,000
14,000
Heating Zone 1 Heating Zone 2 Heating Zone 3
An
nu
al H
eati
ng
Sav
ings
(k
Wh
)
UpgradesConversions
4
Limitations of Current Estimates
• Based on “calibration” to billing analysis of existing homes with forced-air electric furnaces prior to conversion to heat pumps (w/o PTCS)
• All homes in sample were from Heating Zone 1• Analysis “tool” did not fully reflect impact of colder
climate zones nor the impact of alternative control strategies on heat pump performance
• TMY 2 Weather Data• Cost data from DOE Standards process, limited (i.e.,
one) contractor estimates and online prices.
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6th Plan Analysis
• 6th Plan savings estimates based on prior “calibration” for Heating Zone 1– Using current SEEM input assumptions, zonal system “base case” most
closely matched prior calibration – Heat Pump w/PTCS duct sealing & commissioning treated as single
measure– TMY 3 weather files– Kalispell as reference site for Heating Zone 3
• Savings assume home is fully weatherized (i.e., installs all cost-effective thermal shell measures)
• Heat pump & duct sealing cost updated based on Energy Trust of Oregon program data base
6
Base Case Forced Air Furnace Use Assumptions – Crawlspace Homes
0
5,000
10,000
15,000
20,000
25,000
Heating Zone 1 Heating Zone 2 Heating Zone 3
Ann
ual H
eati
ng U
se (
kWh) Prior Base Case
Revised Base Case
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Base Case Forced Air Furnace Use Assumptions – Basement Homes
0
5,000
10,000
15,000
20,000
25,000
Heating Zone 1 Heating Zone 2 Heating Zone 3
Ann
ual H
eati
ng U
se (
kWh) Prior Base Case
Revised Base Case
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Heat Pump Space Heating Use - Crawlspace (w/ PTCS Duct Sealing & Commissioning)
0
2,000
4,000
6,000
8,000
10,000
12,000
Heating Zone 1 Heating Zone 2 Heating Zone 3
Ann
ual S
avin
gs (
kWh)
Current HSPF 8.5/SEER 14
Revised HSPF 8.5/SEER 14
Revised HSPF 9.0/SEER 14
9
Heat Pump Space Heating Use - Basement (w/ PTCS Commissioning)
0
1,000
2,000
3,000
4,000
5,000
6,000
7,000
8,000
9,000
Heating Zone 1 Heating Zone 2 Heating Zone 3
Ann
ual S
avin
gs (
kWh)
Current HSPF 8.5/SEER 14
Revised HSPF 8.5/SEER 14
Revised HSPF 9.0/SEER 14
10
Heat Pump Conversion Space Heating Savings - Crawlspace
(Base Case Forced Air Furnace)
0
2,000
4,000
6,000
8,000
10,000
12,000
14,000
Heating Zone 1 Heating Zone 2 Heating Zone 3
Ann
ual S
avin
gs (
kWh)
Current HSPF 8.5/SEER 14
Revised HSPF 8.5/SEER 14
Revised HSPF 9.0/SEER 14
11
Heat Pump Conversion Space Heating Savings – Basement (Base Case Forced Air Furnace)
0
1,000
2,000
3,000
4,000
5,000
6,000
7,000
8,000
9,000
10,000
Heating Zone 1 Heating Zone 2 Heating Zone 3
Ann
ual S
avin
gs (
kWh)
Current HSPF 8.5/SEER 14
Revised HSPF 8.5/SEER 14
Revised HSPF 9.0/SEER 14
12
Heat Pump Upgrade Savings (Base Case HSPF 7.7/SEER 13 w/o PTCS Duct Sealing & Commissioning
0
1,000
2,000
3,000
4,000
5,000
6,000
7,000
8,000
Heating Zone 1 Heating Zone 2 Heating Zone 3
Ann
ual S
avin
gs (
kWh)
Current HSPF 8.5/SEER 14Revised HSPF 8.5/SEER 14Revised HSPF 9.0/SEER 14
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Revised Conversion and Upgrade Cost Estimate
• Energy Trust Data Base– 1260 Heat Pump Upgrades– 610 Heat Pump Replacements
• Regression Analysis Using Size, HSPF, SEER and “Replacement/Upgrade” as Independent Variables
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Regression Results ( R2 =0.37)
Coefficients* Standard Error t Stat P-value
Intercept ($4,797) 1,223 -3.92 0
Capacity (tons) $508 74 6.87 0
HSPF $205 157 1.3 0.2
SEER $578 48 11.93 0
Upgrade ($775) 114 -6.79 0
*All coefficients significant at the 95% level, except HSFP which is significant at the 80% level.
Heat Pump Cost Regression vs. Reported Cost
Actual Heat Pump Cost vs. Regression Estimated Cost
$-
$2,000
$4,000
$6,000
$8,000
$10,000
$12,000
$14,000
$16,000
$- $2,000 $4,000 $6,000 $8,000 $10,000
$12,000
$14,000
$16,000
$18,000
Actual Cost
Re
gre
ssio
n C
ost
Est
ima
te
16
Heat Pump Conversion and Upgrade Cost
$0
$1,000
$2,000
$3,000
$4,000
$5,000
$6,000
Conversion Upgrade
CurrentProposed
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Findings – The Good News
• All Single Family and Manufactured Home Heat Pump Efficiency Upgrades to HSPF 8.5/SEER 14 and HSPF 9.0/SEER 14 with PTCS Duct Sealing and Commissioning are cost-effective in all zones.
• All Single Family and Manufactured Home Conversions to HSPF 8.5/SEER 14 and HSPF 9.0/SEER 14 with PTCS Duct Sealing and Commissioning are cost-effective in all zones for homes with exterior duct work, i.e., crawlspaces.
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Findings – The Bad News
• No Single Family Conversions to HSPF 8.5/SEER 14 or HSPF 9.0/SEER 14 are cost-effective in any zones for homes with interior duct work, i.e., basements/half basements.
