A Better Fit for High-Temperature Test Chambers

Solving a High-Temperature Challenge with the Right Heating Solution

One of the advantages of custom electric heating is that there isn't one heater that's right for every application. Every heater technology has strengths, and the best solution is usually the one that's designed for the temperatures, environment, and performance the application requires. One TUTCO Farnam customer discovered this while building a series of high-temperature environmental test chambers.

The company had standardized on our silicone rubber heaters for several different pieces of equipment and had been very happy with their performance. Silicone rubber heaters are thin, flexible, easy to install, and provide excellent, even heat. They're a great choice for many OEM applications and were working well throughout most of the customer's product line. The environmental test chambers were the exception. 

To simplify manufacturing, the customer continued using silicone rubber heaters in the chambers even though they regularly operated above the heater's recommended maximum temperature of 428°F (220°C).

There's nothing mysterious about what happens when silicone rubber gets too hot. It starts to break down. First it smokes. Keep pushing it, and eventually the silicone begins to char and burn. The heaters weren't failing because they were poorly made—they were simply being used in an application they weren't designed for.

When the customer contacted TUTCO Farnam, they weren't looking to replace silicone rubber heaters across their entire product line. In fact, they wanted to keep using them because they had proven to be reliable in every other application. They simply needed a heater that could handle the higher temperatures inside the environmental chambers.

Rather than trying to make the existing heater work, our engineers recommended changing heater technologies. A custom mica surface heater was a much better fit for the application. Mica surface heaters are designed to operate at temperatures up to 1,000°F (538°C), and they heat up very quickly. Just as important, we were able to design the new heater with nearly the same footprint as the silicone rubber heater it replaced. That meant the customer could make the change without redesigning the chamber or making significant modifications to the equipment.

The new heaters solved the problem. The environmental chambers now had a heating solution designed for the temperatures they were actually running, while the rest of the customer's equipment continued using silicone rubber heaters where they were the right choice. The conversion required only minor design changes and gave the customer a much more reliable long-term solution.

Projects like this are a good reminder that successful thermal design isn't about finding the "best" heater. It's about selecting the right heater for the job. Silicone rubber heaters are excellent products within their intended operating range. Mica surface heaters are a better choice when the application demands higher temperatures. Knowing where one technology ends and another begins can improve reliability, extend heater life, and eliminate problems before they become expensive.

That's how TUTCO Farnam approaches every project. We start by understanding the application—not by recommending a particular product. Sometimes the right answer is the heater you're already using. Other times, a different heater technology is all that's needed to improve performance. In this case, changing from a silicone rubber heater to a custom mica surface heater gave the customer a solution that fit the application without changing the overall design of their equipment.