Okay BK, go ahead, egg me on! Here goes.
I was answering LTB's original question:
One thing that puzzles me is why many people think that turning the fans on and blowing air across the top of the stove and directly onto the coil of the cat prob would cool the cat itself? Unless I’m missing something it just doesn’t make sense
And in doing so spoke explicitly of open-loop performance, which ignores the action of the thermostat.
My point remains a simple one, but one that is often overlooked--cooling the outside of a stove cools the inside too, cat included.
Regarding that, and remembering that I'm still talking open-loop, I'd like to make one clarification. LTB said:
Before the cat is put in place it is wrapped in a gasket, then it is placed in a metal holder then wrapped in another gasket. Now it is placed in the front of the chamber. Once the stove starts to heat up both gaskets expand to seal it in place. you now have 2 layers of insulation separating the cat from the metal surfaces so there isn’t enough temp difference to overcome the insulation in this case.
To split hairs in the interest of insight, I do not believe that is precisely the case, for two reasons.
First, thermodynamics says that cooling one side of a conductive path (the stove surface) cools the other side (the cat), regardless of the amount of insulation. The more insulation the less the change, but there is still cooling. That said, if there is enough insulation along a particular thermal path, the cooling by that path is trivial, which may be what LTB meant by "there isn’t enough temp difference to overcome the insulation in this case."?
The second factor is that conduction by the cat mount is not the only cooling path--there is also radiation from cat to stove skin, and conduction by the flue gases, which carry heat to the stove skin. Both the "cool sides" of these paths are made cooler by cooling the stove skin, and will cool the cat. How much can be debated, but it does happen, which is my answer to the original question. (In fact I was going to suggest you try blowing a fan directly on the area around the cat.)
LTB went on to talk about closed-loop dynamics, on the longer time scale that allows the thermostat to react, and his description makes sense to me. However, closed-loop operation involves so many variables that I don't think anyone could accurately guess net cat temperature response--up? down? none? It depends on how the stove is tuned, production tolerances, flue, time frame, etc.
My original point remains--there is a sensible explanation for how cooling the stove surface can cool the cat.
Happy?
Awake?
In fact the specific issue is fairly trivial, except for the take-away that it might be worthwhile putting a fan on the cat area. Perhaps LTB simply meant that knowing what he does about the stove layout, he doesn't think cooling the skin would cool the cat much, and if so I take his point. I heeded your urging primarily in hopes that someone, myself included, finds it somewhat enlightening and entertaining. I'm often wrong, and apologize if this seems irrelevant or annoying.