deemed savings input assumptions for ptcs duct sealing in existing manufactured homes
DESCRIPTION
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 PresentationTRANSCRIPT
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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