Baltimore Aircoil Specific Cost, c Cooling and c Condensing Baltimore Aircoil Company (BAC) is a manufacturer of cooling and condensing towers which provides extensive online documentation on the performance of small-and medium-size cooling towers (BAC, 2020). The BAC estimator provides parasitic load and heat rejection for each model as a function of cooling tower parameters, such as ambient air temperature. Additionally, budgetary numbers for BAC units were obtained from a vendor.