Wood stove top fans (heat powered)

[MossRoad]

2017, cold stove lighting.

 

[MossRoad]

26 minutes later, shut down the full open air control and open it a couple bars.

 

[MossRoad]

2 hours later...

 

[Egon]

Radiant heat: energy particlues striking a solid object and transfering energy to that object.

Conduction: transfer of energy between objects in contact with each other. Always high to low.

Convection: energy being transported to other locations.

THE LOW PAY GRADE version

 

[Jstpssng]

I'm starting to understand how people get so many posts-as I call the kettle black...

 

[MossRoad]

I'm starting to understand how people get so many posts-as I call the kettle black...

I had the day off.

 

[MapleLeafFarmer]

I just started using one of these fans this year. My understanding is these use different metals, that when subjected to a heat differential, create a voltage that powers the fan (I.e. a Peltier device).
My wood stove top surface is about 20” x 30”

Question / shower thought: Where is best place to set fan on stove top? Middle, front edge (drawing hot from stove and blowing away from stove), or back edge (drawing cooler air and blowing across stove top)?

Assumption #1: Let’s assume surface top is uniform heat and fan will generate same voltage to motor no matter location.

At back edge: Does blowing cold dense air across stove move more air? But does it take more torque and fan is slower? So air volume is same? And does heated cold air now just rise and circulate the same as it would without fan?

At front edge: Fan might spin faster (as there’s less hot air resistance), and air may be pushed laterally as desired, but does fan move as much hot air?

I have one, put it at the back of the stove so it blows over the slots on the stove top surface that heat comes out of.

I like to watch it spin, fast when really hot, slow when cooler.

Don't think it moves any amount of air to speak of though (haha) will move the smoke from a match thats flaming out but not much more.

Other than the entertainment value of watching it spin and it looks "pretty".... I think I wasted $100 on mine.

 

[Doofy]

I have one, put it at the back of the stove so it blows over the slots on the stove top surface that heat comes out of.

I like to watch it spin, fast when really hot, slow when cooler.

Don't think it moves any amount of air to speak of though (haha) will move the smoke from a match thats flaming out but not much more.

Other than the entertainment value of watching it spin and it looks "pretty".... I think I wasted $100 on mine.

Same here but I bought knowing they were worthless for really moving air. I've seen some larger ones with an aircraft looking propeller move a bunch of air.

 

[CalG]

where does an air molecule store heat energy to then pass on to another air molecule?

VELOCITY!

 

[CalG]

LOL...motion is not thermal.

All forms of energy resolve to HEAT energy as their final resting place.

In order to SLOW a moving object, It must give up heat. Even a Neutrino emitts a burst of thermal detectable energy IF it strikes an atom of scinillation prone quartz.

Adiabatic cooling of the air as it rises is example of a similar necessity based on pressure change.

Even though our understanding of the many phenomenon that surrounds us is imperfect, Boyle's Gas Laws are well described and agreed upon.

Again, Stick you hand in a hot oven, Just don't touch anything! ;-)