Deemed Savings Input Assumptions for PTCS Duct Sealing in Existing Manufactured Homes
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1 Deemed Savings Input Assumptions for PTCS Duct Sealing in Existing Manufactured Homes February 10, 2004
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Deemed Savings Input Assumptions for PTCS Duct Sealing in Existing Manufactured Homes. February 10, 2004. Current Assumptions. Basis for Reconsideration. Pre & Post Duct Blaster Test on nearly 2400 Manufactured Homes Data implies that “baseline” duct leakage is higher than assumed - PowerPoint PPT Presentation
Transcript of Deemed Savings Input Assumptions for PTCS Duct Sealing in Existing Manufactured Homes
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Deemed Savings Input Assumptions for PTCS Duct Sealing in Existing
Manufactured Homes
February 10, 2004
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Current Assumptions
Assumption Zone 1 Zone 2 Zone 3
Baseline Duct Efficiency,
10% Supply Losses
84% 83% 82%
PTCS Duct Efficiency,
5% Supply Losses
89% 88% 88%
Savings w/FAF & No CAC (kWh/yr)
900 1,317 1,607
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Basis for Reconsideration
• Pre & Post Duct Blaster Test on nearly 2400 Manufactured Homes
• Data implies that “baseline” duct leakage is higher than assumed
• Revised Duct System Efficiency model (used for PTCS “sliding scale” calculator) specifically addresses manufactured home construction
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Pre-PTCS Duct Sealing CFM/SF25
0%
2%
4%
6%
8%
10%
12%
14%
0.04 0.12 0.2 0.28 0.36 0.44 0.52 0.6 0.68 0.76 0.84 0.92 1
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Post-PTCS Duct Sealing CFM/SF25
0%
5%
10%
15%
20%
25%
30%
35%
0.04 0.12 0.2 0.28 0.36 0.44 0.52 0.6 0.68 0.76 0.84 0.92 1
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Difference Between Pre & Post PTCS Duct Sealing - CFM/SF25
0%
5%
10%
15%
20%
25%
30%
0.04 0.12 0.2 0.28 0.36 0.44 0.52 0.6 0.68 0.76 0.84 0.92 1
Summary Statistics
ALL Homes in CC Data base
N=2386
Square Footage
Pre duct blaster CFM 50 P
Post duct blaster CFM 50 P
Mean 1,174 278 117 Median 1,152 222 90 Std Deviation 356 211 117 Mode 1,344 140 44 25% Percentile 896 142 58 75% Percentile 1,440 347 133
More Summary Statistics
ALL Homes in CC Data base N=2386
Pre CFM @ 25 P
Post CFM @ 25 P
Difference CFM/SF @ 25 P
Mean 177 74 103 Median 141 57 80 Std Deviation 135 74 105 Mode 89 28 - 25% Percentile 90 37 38 75% Percentile 221 84 138
Still More Summary Statistics
ALL Homes in CC Data base N=2386
Pre CFM/SF @ 25 P
Post CFM/SF @ 25 P
Difference CFM/SF @ 25 P
Mean 0.16 0.07 0.09Median 0.12 0.05 0.07Std Deviation 0.13 0.07 0.10Mode 0.09 0.04 0.0025% Percentile 0.08 0.03 0.0375% Percentile 0.20 0.07 0.12
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Recommendation
• Use “Median” differential value of 80 CFM25 as most representative of distribution of both pre and post-PTCS duct tightness
• Use PTCS “Sliding Scale” deemed savings calculator duct modeling assumptions for manufactured homes to to derive deemed savings
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Revised Assumptions
Assumption Zone 1 Zone 2 Zone 3
Baseline Duct Efficiency,
12% Supply Losses
81% 78% 76%
PTCS Duct Efficiency,
5% Supply Losses
92% 92% 92%
Site Savings w/FAF & No CAC (kWh/yr)
1,151 2,305 3.071
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Current vs Revised Credits
Case Zone 1 Zone 2 Zone 3
Existing
Site Savings w/FAF & No CAC (kWh/yr)
900 1,317 1,607
Existing C&RD Credit $303 $456 $581
Revised
Site Savings w/FAF & No CAC (kWh/yr)
1,151 2,305 3.071
Revised C&RD Credit $360 $715 $954
