Round One: Continuous Heat
Method
Each sample was sealed with DEI Cool Tape (not being evaluated as part of this article!). Each sample was then fitted with a thermocouple and placed within a closed oven with temperature stabilized at 200F (as referenced by a second thermocouple). After 4 minutes’ time (an arbitrary figure), the sleeve-protected thermocouple’s temperature reading was noted. Where the product was based on a hook-and-loop closure (aka velcro), the seam was sealed with DEI Cool Tape.
Results
Remarkably, all of the samples not only failed this test, the thermocouple reading inside the material was higher than the oven temperature. Unconvinced by the results, both thermocouples were put through calibration tests and passed with flying colors. The 200F closed oven test was performed again with nearly identical results. I cannot explain this. The results are as follows (left axis is temperature in F).
Conclusion
These products are not up to the task of providing protection from continuous heat in the absense of ambient airflow of some sort. This was confirmed by one of the manufacturers who reported, “The
sleeve we sent you (I am sure the other brands operate in the same fashion) are designed for open areas with some airflow.”
But don’t some of the products say they can handle “continuous heat” up to a certain temperature? Yes, they do.
- Heatshield Products Reflect-A-Sleeve: “Reflect-A-Sleeve withstands 1100°F continuous of radiant heat and 500°F direct heat.”
- DEI Heat Sheath: “The Heat Sheath will reflect up to 90% of the radiant heat and can insulate against up to 500 degrees direct continuous heat.”
Apparently, like all marketing, everything is in the subjective meaning of the often vague phrases used. I am sure both of these companies can explain what they mean by their statements, but I consider both statements to be misleading. Neither of the 2 products performed at even 200F continuous heat. ThermoTec wisely makes no such claim of their Express Sleeve product.
Let’s move on and test with some ambient air present.
