Heat powered fans, can they be placed on side of stove?

[morganp107]

Hi Folks,

I am installing a freestanding woodstove in my large fireplace. I have come across heat powered fans and I am intrigued by them. However, I do not have clearance above my stove to install it on the stove top. I was curious if they can be installed on the side of a stove? Thanks for any insights!

 

[jetsam]

Short answer: No. The TEG needs a big heat differential to work.

Long answer: Maybe, if you have a stove with flat metal sides and a way to attach the fan in such a way that you get very good thermal conductivity. Maybe samarium-cobalt magnets? Now you are also looking at needing a fan with a ferrous heat sink (I think a lot of them are aluminum), and the magnets are likely not strong enough. Even if they were, does the side of the stove get hot enough to spin the fan? Even if it does, is the fan doing any meaningful work down there away from the hot stovetop?

There are even worse answers (self-tapping screws).

A better and easier answer would be to screw a tegfan to a 1/4" x 6" x (however far out it needs to protrude to clear the fireplace) piece of steel bar stock, and put a brick on the stove side of the plate to hold it down if needed.

Also, the fan doesn't *have* to be adjacent to the TEG and heat sink... but the fan is cooling the cool side of the TEG, so the further out you put the fan motor, the less voltage it will generate. It's possible that you could move the fan blade out onto a long shaft, and add a small chipset fan behind the heat sink to cool it directly.

I want pictures if you try any of this stuff!

 

[begreen]

Theoretically possible but they have no mounting holes and to do so would mean tapping into the stove body. A small electric fan on the hearth could be more effective. What stove is this? Will there be a damper area sealing block-off plate in place?

 

[wooduser]

Hi Folks,

I am installing a freestanding woodstove in my large fireplace. I have come across heat powered fans and I am intrigued by them. However, I do not have clearance above my stove to install it on the stove top. I was curious if they can be installed on the side of a stove? Thanks for any insights!

Ummm. In my experience the main purpose of a fan is to break up the stratified layers of heat near the ceiling, and cold near the floor. For that I find a cheap box fan placed pretty much anywhere to be the best solution to that issue.

 

[bholler]

Ummm. In my experience the main purpose of a fan is to break up the stratified layers of heat near the ceiling, and cold near the floor. For that I find a cheap box fan placed pretty much anywhere to be the best solution to that issue.

Or to aid in convecting heat off of the stove by moving air over the surface. That is what stove blowers are for and what the thermoelectric fans attempt. They simply dont move enough air to be effective but they are kind of cool.

 

[bholler]

Hi Folks,

I am installing a freestanding woodstove in my large fireplace. I have come across heat powered fans and I am intrigued by them. However, I do not have clearance above my stove to install it on the stove top. I was curious if they can be installed on the side of a stove? Thanks for any insights!

Sure they can be installed wr here ever you want to install them. They just wont do anything in most locations.

Honestly they are a pretty cool novelty but are not very effective no matter where they are installed.

 

[wooduser]

Or to aid in convecting heat off of the stove by moving air over the surface. That is what stove blowers are for and what the thermoelectric fans attempt. They simply dont move enough air to be effective but they are kind of cool.

Is it really desirable to strip away additional heat from the stove? My supposition is that stove designers designed in a certain relationship between heat produced by the fire and heat going into the ambient air. If that's the case, you wouldn't need a fan, and operating a fan might cool off the stove more than it's designed for.

In particular, operating a fan with a small or medium fire might tend to cool off the combustion in the stove excessively.

I know when I'm starting a fire, I want the fire as hot as I can get it as fast as I can get it.

I suggest that we don't really know what a fan does to the combustion process, since you'd need a skilled person with a combustion gas analyzer to sort out what happens. However, does it seem likely that a stove that is designed to operate properly without a fan will operate as well or better with a fan blasting away on high? I pose the question without really knowing the answer.

The only time I really value a fan is when the stove is blasting away with a hot stove and a hot fire when I may direct the air from my box fan across the stove. Even then, however, I don';t really need a fan located in the stove!

 

[bholler]

Is it really desirable to strip away additional heat from the stove? My supposition is that stove designers designed in a certain relationship between heat produced by the fire and heat going into the ambient air. If that's the case, you wouldn't need a fan, and operating a fan might cool off the stove more than it's designed for.

In particular, operating a fan with a small or medium fire might tend to cool off the combustion in the stove excessively.

I know when I'm starting a fire, I want the fire as hot as I can get it as fast as I can get it.

I suggest that we don't really know what a fan does to the combustion process, since you'd need a skilled person with a combustion gas analyzer to sort out what happens. However, does it seem likely that a stove that is designed to operate properly without a fan will operate as well or better with a fan blasting away on high? I pose the question without really knowing the answer.

The only time I really value a fan is when the stove is blasting away with a hot stove and a hot fire when I may direct the air from my box fan across the stove. Even then, however, I don';t really need a fan located in the stove!

You do realize those fans are part of the design of those stoves right? The stoves have been tested with them on. Any yes it is desirable to strip more heat off if you need more heat inthe house.