When the compressed air cost basis is selected (utility_type = 0), the annual cost is the product of the compressed air utility rate and the annual air volume. This basis is appropriate when the facility purchases compressed air from an external supplier or has an internally established cost-per-scf transfer price.

\begin{equation}\label{eq:leak-survey-ca-cost} C_{cost} = r_{ca} \cdot V_{annual} \end{equation}

Symbols

\(C_{cost}\)	Annual compressed air cost of leaked air \([\unit{ \dollar\per\year}]\)
\(r_{ca}\)	Compressed air utility rate \([\unit{ \dollar\per\cubic\foot}]\)
\(V_{annual}\)	Annual compressed air volume for this survey entry \([\unit{ \scf}]\)

Note: When utility_type = 0 (compressed air), annual_total_electricity in the compressed_air_leak_survey::Result remains zero. Only annual_total_electricity_cost is populated.