While direct heating can be more efficient and cost effective, there are instance where indirect heating has its place and has cost advantages over direct heating.
Water Bath is indirect heating where it heats up the water in the tank and the hot water transfer heat to the process pipes running through it. It is cost effective for high pressure application where the tank and heater design at atmospheric and only the pipe cater for high pressure process.
Type of Heat Source : Electric or Fire (burner)
Capacity : design to meet
Control : Local Contactor control (Electric) BMS (burner)