300 degree drop

Depends on what stage of the burn from 700 likely down quite a bit if thing are dying down abit in the burn chamber. mine will sink to about 350-400 maybe 500 at the peak of a burn. on tail end, gauge will read about 300. lot depends on the fuel too.

Wood that is not dry enough is my guess.

Your stove top measuring device, if it is a regular magnetic thermometer uses a bimetallic coil exposed to the air. If you or the fans blow on the coil, you cool it, and the needle moves down a lot.

If you use an IR thermometer I suspect that the temp drop is actually almost nothing.

Hogwildz said:

Wood that is not dry enough is my guess.

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yep

begreen said:

I've seen 150F drop, but not 300F. Might just be coincidence with the timing of the fan turn on? How much wood was in the stove and how long had it been burning?

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And where are you measuring with what kind of thermometer?

Highbeam said:

Your stove top measuring device, if it is a regular magnetic thermometer uses a bimetallic coil exposed to the air. If you or the fans blow on the coil, you cool it, and the needle moves down a lot.

If you use an IR thermometer I suspect that the temp drop is actually almost nothing.

Click to expand...

I find this to be true.
Remember the fan air may be blowing directly on and across the magnetic thermometer thus cooling the actual device itself and giving a sort of "false" result of the stove top.

I have TWO stove top thermometers on my stove. One sits on the upper deck and the other sits on the lower deck.
When I turn on the fan, the upper deck device always drops MUCH quicker and lower than the other one because it receives more air on it.

As stated,(by Highbeam) an IR gun will give truer results.

Also, remember when using a fan to lower temps during an over-fire, you are not really taming the fire inside, just the temp of the steel top. (or maybe ONLY the thermometer itself)

Build a shield with foil and magnets to go behind your thermo so it redirects the air around it. I find I can take alum. foil and fold it over several times to make it rigid then use magnets to keep it attached to the stove, it might not stand up to the blower on high.

Highbeam said:

Your stove top measuring device, if it is a regular magnetic thermometer uses a bimetallic coil exposed to the air. If you or the fans blow on the coil, you cool it, and the needle moves down a lot.

If you use an IR thermometer I suspect that the temp drop is actually almost nothing.

Click to expand...

That's the right answer in my opinion. Also, if you have a regular thermostat in the room. Check out what happens to that temp after the fan has been on for say, 2 hours. If your temp holds or rises, then the stove is working as it should. Moving air cools objects, but the energy is transferred to the air and shot into the house. Hard to make energy vanish...unless there is a black hole...which is why I got divorced...