Annual consumption is the total instantaneous leak flow rate scaled by the number of operating hours per year, with a conversion from minutes to hours (factor of 60) and from standard cubic feet to kiloscf (factor of 1000). This gives the projected yearly air loss in kiloscf, a practical unit for annual energy assessment.

\begin{equation}\label{eq:orifice-method-annual-consumption} C_{annual} = \frac{Q_{leak} \cdot t_{op} \cdot 60}{1000} \end{equation}

Symbols

\(C_{annual}\)	Estimated annual compressed air loss \([\unit{ \kscf}]\)
\(Q_{leak}\)	Total volumetric leak flow rate \([\unit{ \scfm}]\)
\(t_{op}\)	Annual system operating time \([\unit{ \hour}]\)
\(60\)	Minutes per hour conversion \([\unit{ \minute\per\hour}]\)
\(1000\)	Standard cubic feet per kiloscf conversion \([\unit{ \unitless}]\)

Note

The result is in kiloscf (kscf), where 1 kscf = 1000 standard cubic feet. This unit is conventional for annual compressed air volumes in industrial energy assessments.