The two largest categories of energy consumption in a sugar factory, after the boilers, are concentration of clear juice to syrup and process heating duties serviced using evaporator vapour bleeds. These cannot be measured directly, since both are supplied by the same exhaust steam fed to the evaporator station. In this study, an algorithm was developed to separate the evaporator exhaust steam demand into the amount required to concentrate clear juice to syrup and the amount that is required for raising vapours for downstream process heating duties. The algorithm was generalised for different evaporator station configurations, different exhaust steam conditions, and varying clear juice and syrup concentrations and temperatures. The algorithm was applied to factory data to demonstrate its application for investigating the cost of combined downstream process heating demand on the factory energy bill.