1

Proposed Revisions to Deemed Savings Input Assumptions for PTCS Duct Sealing and Heat Pump Efficiency Upgrades and Duct Sealing,

Commissioning and Controls in Existing Homes

January 8, 2007

2

Issue

• Current deemed savings analysis assumes that existing single family and manufactured homes with heat pumps have the same average size as homes with any electric heating system

• Average home size assumptions– Pre-79 Single Family – 1600 sq.ft– Post79/Pre93 Single Family – 2200 sq.ft.– Post92 Single Family – 2300 sq.ft.– Existing Manufactured Home – 1020 sq.ft– New Manufactured Home – 1636 sq.ft..

3

Average Size of Single Family Homes in Regional Heat Pump Savings Evaluation

Vintage FAF w/o CAC FAF w/ CAC Heat Pump All

Pre79 2,232 1,887 2,621 2,069

Post79/Pre93 2,276 1,710 2,406 2,278

Post92 2,333 1,963 2,376 2,271

All 2,263 1,883 2,477 2,146

4

Average Pre79 Single Family Homes in Regional Heat Pump Evaluation Were Significantly Larger Than RTF

Assumes

2,6212,406 2,376

1600

2200 2300

0

500

1,000

1,500

2,000

2,500

3,000

Pre79 Post79/Pre93 Post92

Vintage

Ho

use

Siz

e (

sq.ft

.)

Heat Pump RTF

5

Average Size of Manufactured Homes in Regional Heat Pump Savings Evaluation

Vintage FAF w/o CAC FAF w/CACHeat Pump All

Pre79 1,662 NA 1,650 1,661

Post79/Pre93 1,706 1,716 1,881 1,728

Post92 1,758 1,887 NA 1,762

All 1,711 1,802 1,823 1,721

6

Average Pre79 Manufactured Homes in Regional Heat Pump Evaluation Were Significantly Larger Than RTF

Assumes

1,650

1,8811800

1021

1636 1636

0

200

400

600

800

1,000

1,200

1,400

1,600

1,800

2,000

Pre79 Post79/Pre93 Post92Vintage

Ho

me

Siz

e (

sq.ft

.)

Heat Pump RTF

7

Do These Larger Homes Use Proportionately More Space Heating?

• Compared Regional Heat Pump Evaluation’s Estimated “Pre-Retrofit” Space Heating Use to RTF Assumptions– Problems

• Data for homes with pre-existing heat pump in Heating Zone 1/Cooling Zone 1 (sample primarily from Olympic Peninsula and OR Coast)

• Sample sizes are small or non-existent, especially for MH

– Issue: Should these homes usage be used to modify the RTF baseline (Pre-PTCS measure) space heating estimates

8

Estimated Single Family Space Heating Use Pre-Retrofit All Forced Air System Types

Heating Zone 1 Cooling Zone 1

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

FAF Z1/Z1 FAF w/CAC Z1/Z1 HP Z1/Z1System Type

Pre

-Ret

rofit

SpH

t-N

AC

(kW

h/sq

.ft.

yr)

Pre79

Post79/Pre93

Post92

Were these heat pumps functioning?

9

Estimated Single Family Space Heating Use Pre-Retrofit All Forced Air System Types

Heating Zone 1 Cooling Zone 2

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

FAF Z1/Z2 FAF w/CAC Z1/Z2 HP Z1/Z2System Type

Pre

-Ret

rofit

SpH

t-N

AC

(kW

h/sq

.ft.

yr)

Pre79

Post79/Pre93

Post92

10

Estimated Single Family Space Heating Use Pre-Retrofit All Forced Air System Types

Heating Zone 1 Cooling Zone 3

0.0

1.0

2.0

3.0

4.0

5.0

6.0

FAF Z1/Z3 FAF w/CAC Z1/Z3 HP Z1/Z3System Type

Pre

-Ret

rofit

SpH

t-N

AC

(kW

h/sq

.ft.

yr)

Pre79

Post79/Pre93

Post92

Were these heat pumps functioning?

11

Estimated Single Family Space Heating Use Pre-Retrofit Heat Pump Systems

Heating Zone 1 All Cooling Zones

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

HP Z1/Z1 HP Z1/Z2 HP Z1/Z3

Climate Zone

Pre

-Re

tro

fit S

pH

t-N

AC

(kW

h/s

q.ft

.yr)

Pre79 Post79/Pre93 Post92

Were these heat pumps functioning?

12

Estimated Single Family Heat Pump Home Space Heating Use Pre-Retrofit –

Heating Zone 1 All Cooling Zones

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

HP Z1/Z1 HP Z1/Z2 HP Z1/Z3

Climate Zone

Pre

-Ret

rofit

SpH

t-N

AC

(kW

h/yr

)

Pre79

Post79/Pre93

Post92

Assuming Heat Pumps in Cooling Zone 1 Were Functioning Increases Single Family Baseline Consumptions Estimates –

Especially for More Recently Built Homes

House Vintage Pre79 - Excl CZ1

Pre79 - All

Post79/Pre93 - Excl CZ1

Post79/Pre93 - All

Post93 - Excl CZ1

Post93 - All

N 16 27 13 36 3 13

House Size 2,232 2,621 2,267 2,406 2,472 2,376

Space Heating Use (kWh)

10,460 11,589 7,014 10,619 6,240 12,279

Space Heating Use (kWh/sq.ft./yr)

4.7 4.4 3.1 4.4 2.5 5.2

14

Estimated Manufactured Home Space Heating Use Pre-Retrofit All Forced Air System Types

Heating Zone 1 Cooling Zone 1

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

FAF Z1/Z1 FAF w/CAC Z1/Z1 HP Z1/Z1System Type

Pre

-Ret

rofit

SpH

t-N

AC

(kW

h/sq

.ft.

yr)

Pre79

Post79/Pre93

Post92

15

Estimated Manufactured Home Space Heating Use Pre-Retrofit All Forced Air System Types

Heating Zone 1 Cooling Zone 2

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

FAF Z1/Z2 FAF w/CAC Z1/Z2 HP Z1/Z2System Type

Pre

-Ret

rofit

SpH

t-N

AC

(kW

h/sq

.ft.

yr)

Pre79

Post79/Pre93

Post92

16

Estimated Manufactured Home Space Heating Use Pre-Retrofit Heat Pump Systems

Heating Zone 1 All Cooling Zones

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

HP Z1/Z1 HP Z1/Z2 ALL HP

Climate Zone

Pre

-Ret

rofit

SpH

t-N

AC

(kW

h/sq

.ft.y

r)

Pre79

Post79/Pre93

17

Estimated Manufactured Home Heat Pump Home Space Heating Use Pre-Retrofit – Heating Zone 1 All Cooling Zones

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

HP Z1/Z1 HP Z1/Z2 All Zone 1

Climate Zone

Pre

-Ret

rofit

SpH

t-N

AC

(kW

h/yr

)

Pre79

Post79/Pre93

Post92

18

Single Family Heat Pump Zone 1 Space Heating Evaluation Estimates Compared to Current RTF Assumptions (kWh/sq.ft.)

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

HP Z1/Z1 HP Z1/Z2 HP Z1/Z3 HP Zone 1 -All Cooling

Zones

HP Zone 1Cooling

Zones 2 & 3

RTF

Climate Zone

An

nu

al U

se (

kWh

/sq

.ft./y

r) Pre79 Post79/Pre93 Post93

19

Single Family Heat Pump Zone 1 Space Heating Evaluation Estimates Compared to Current RTF Assumptions (kWh/sq.ft.)

0.0

1.0

2.0

3.0

4.0

5.0

6.0

HP Zone 1 - All CoolingZones

HP Zone 1 Cooling Zones 2 &3

RTF

Climate Zone

An

nu

al U

se (

kWh

/sq

.ft./y

r)

Pre79 Post79/Pre93 Post93

20

Estimated Single Family Heat Pump Zone 1 Space Heating Evaluation Estimates Compared to Current

RTF Assumptions

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

Annual Use - w/Cool Zone1

Annual Use - w/o CoolZone 1

RTF - Zone 1

Climate Zone

Pre

-Re

tro

fit S

pH

t-N

AC

(kW

h/y

r)

Pre79

Post79/Pre93

Post93

21

Manufactured Home Heat Pump Zone 1 Space Heating Evaluation Estimates Compared to Current RTF Assumptions

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

All Zone 1 RTFClimate Zone

Pre

-Re

tro

fit S

pH

t-N

AC

(kW

h/s

q.ft

.yr) Pre79

Post79/Pre93Post92

Note: Post92 Construction use estimate from RCDP

22

Estimated Manufactured Home Heat Pump Zone 1 Space Heating Evaluation Estimates Compared to

Current RTF Assumptions

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

All Zone 1 RTF

Climate Zone

Pre

-Re

tro

fit S

pH

t-N

AC

(kW

h/y

r) Pre79

Post79/Pre93

Post92

Note: Post92 Construction use estimate from RCDP

23

Recommendation – Single Family

0

2,000

4,000

6,000

8,000

10,000

12,000

Pre79 Construction Post79/Pre93 Post93 Construction

Ann

ual S

pace

Hea

ting

Use

(kW

h)

Evaluation Estimate

Current RTF

Proposed RTF

24

Recommendation – Manufactured Homes

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

Pre94 Post93 NonSGC SGC/Energy Star

Ann

ual S

pace

Hea

ting

Use

(kW

h)

Evaluation Estimate

Current RTF

Proposed RTF

Note: Estimated use of SGC/Energy Star heat pump homes derivedFrom RCDP analysis which found annual use of 2.6 – 3.2 kWh/sf/yr.

25

Impact of Revised Base Case Space Heating Use Assumptions on PTCS Measure Cost-Effectiveness

• Some changes in status of any heat pump upgrade measures– Upgrades for all vintages of MH in all climates zones are now

cost-effective, including SGC/NEEM– Upgrades for all vintages and foundation types of SF homes

in all climates zones are now cost-effective, including half/full basements in Heating Zone 1

• PTCS Duct sealing, system commissioning & controls measure is now cost-effective for SGC/NEEM homes with existing or newly installed heat pumps in all climates zones