Calculators › Industrial systems: air, pumps, fans, heat recovery Load-unload leakage repair benefit calculator
Load-unload leakage repair benefit
For unchanged loaded and unloaded powers, compare average input before and after repair using the measured duty fractions; assume this measured condition represents the stated annual hours.
S = ( P load − P unload ) × ( D before − D after ) 100 × h × p S = \frac{\left(P_{\text{load}} - P_{\text{unload}}\right) \times \left(D_{\text{before}} - D_{\text{after}}\right)}{100} \times h \times p S = 100 ( P load − P unload ) × ( D before − D after ) × h × p
Calculator
Enter the values you know and leave one box empty. Calculate finds the empty one, the result or any input.
Worked example
Given
P load P_{\text{load}} P load 90 kW P unload P_{\text{unload}} P unload 22 kW D before D_{\text{before}} D before 24 % D after D_{\text{after}} D after 10 % h h h 3,600 h/yr p p p 0.14 $/kWh S = ( 90 − 22 ) × ( 24 − 10 ) 100 × 3600 × 0.14 ≈ 4 , 798 S = \frac{\left(90 - 22\right) \times \left(24 - 10\right)}{100} \times 3600 \times 0.14 \approx 4{,}798 S = 100 ( 90 − 22 ) × ( 24 − 10 ) × 3600 × 0.14 ≈ 4 , 798
Symbols and units
Symbol Meaning Unit
S S S annual energy-cost reduction $/yr P load P_{\text{load}} P load loaded input power kW P unload P_{\text{unload}} P unload unloaded input power kW D before D_{\text{before}} D before loaded duty before repair % D after D_{\text{after}} D after loaded duty after repair % h h h annual operation on the tested duty h/yr p p p energy price $/kWh
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