In cold climates, water or chemical pipework often needs to be heat traced to prevent freezing. Thermal insulation alone is incapable of preventing freezing. A 25mm bore pipe at 5°C having 25mm thick insulation will reach freezing point within one hour in an ambient temperature of -10°C.
Steam at, say 150°C, is not a viable fuel source for simple freeze protection and of course, condensate returns may themselves freeze. Electric heat tracing having a low power output is the most convenient and efficient option.The type of control system will determine operating costs.