The bag sub-calculator returns an annual consumption in kscf that already accounts for the operating time specified in the bag method input. The survey converts this result to standard cubic feet before applying its own units multiplier so that aggregate survey totals use scf for all measurement methods.

\begin{equation}\label{eq:leak-survey-bag-annual} V_{annual} = C_{bag} \cdot 1000 \cdot n \end{equation}

Symbols

\(V_{annual}\)	Annual compressed air volume for this survey entry \([\unit{ \scf}]\)
\(C_{bag}\)	Annual consumption from bag_method::calculate \([\unit{ \kscf}]\)
\(1000\)	Kiloscf to standard cubic feet conversion \([\unit{ \unitless}]\)
\(n\)	Number of identical leak points (units multiplier) \([\unit{ \unitless}]\)

Note: The bag_method::Input.operating_time field governs the period over which annual consumption is computed for bag-method entries; it is not overridden by the survey's hours_per_year field (unlike the estimate method).