In this online-only sidebar to "Cartridge Heater Considerations," the author offers tips for factoring in the cost of heating when selecting cartridge heaters. 

When it comes to selecting a cartridge heater, the cost is almost as important as other considerations such as how it will perform in certain processes and environment. And, it can be a tricky factor to determine because the price of the heater vs. the cost of heating in an application can vary wildly.

The purchase price of a particular cartridge heater may be much more attractive than another, but the purchaser may have no idea what the maintenance manager is going through. And the buyer may not understand how much more he is paying for the use of the wrong heater.

Effective heat transfer will drop operating costs to heat a manufacturing operation. If one heater price is three-quarters of another, but the other lasts twice as long, it will improve operating life costs substantially. Longer life translates to decreased maintenance costs and machine downtime. Heater change-out costs can far exceed the initial cost of the cartridge.

If a cartridge heater seizes in a bore, the tool, platen or die must be pulled and sent to the machine shop, generally to drill out the heater, a time-consuming and expensive procedure. If a split-sheath cartridge heater is used, this problem will be eliminated, or if a conventional heater is sized properly, this concern can generally be avoided.

To maximize on the cost of heating, the effective purchaser of cartridge heaters must be aware of the quality of a heater, its use and life in an application, and the ramifications of failure on replacement and maintenance.