Stirling engine fan for top of woodstove

[aloneagain55]

I have the thermoeletric stove fans but really wanted to try a stirling engine fan for my woodstove top.

Are there any companies selling them that dont cost 100s of dollars ? I dont care if the unit doesnt look like a work of art, I just care that it functions well and blows out more air then peltier type stove fans.. Ty

[Bumpkin]

I was gifted one of those peltier fans - "I Know you live off-grid and you'll just love this." It worked silently and reliably and pretty much uselessly. I either threw it away or it's stored away somewhere, I dunno. Not that they couldn't serve a purpose, but the best way to spread the heat of a wood stove is to start with a floor-plan that places the stove central so there's not much spreading to do. Which I ingeniously did, only to stupidly later add on a back room that's colder than a witch's broom. It'd be nice to blow some heat back there at night but of course it'd just be an extra battery drain on my solar power. So - though my short answer to your question from my own knowledge is no, I sure hope someone with experience chimes in. Otherwise, if you throw yourself on the mercy of the market I hope you report back. Meanwhile, welcome to the forum and best wishes for a warm house.

Bumpkin

[Tom Booth]

The Vulcan stove fan is about $150 (not including international(?) shipping) so technically I guess, not "hundreds" (plural), but still over $100.

https://www.gyroscope.com/d.asp?product ... gecurrency

However, I never owned one, don't know anything about quality, reliability, customer service, CFM air flow, actual availability etc.

I'm not even sure that is the actual company website "gyroscope.com"?

Also for sale from Kontax for $188.99

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Image from Kontax website:

https://www.stirlingengine.co.uk/d.asp? ... gecurrency

But includes "FREE worldwide shipping !" and 3 year "comprehensive manufacturer warranty" whatever that means.

A few reviews on that site seem a bit iffy, suggesting it may wear out or something after a season or two of continuous operation.

I wanted one, waited years and years it seemed, for it to be back in stock but was always sold out as I recall. Seems it is available at the moment.

Not currently available from Amazon, but there are some old reviews:

https://www.amazon.com/Vulcan-Stove-Fan ... B002Y4UOYM

They also offer a "Mini Vulcan":

https://www.stirlingengine.co.uk/d.asp? ... VULCANMINI

Some specifications on this page:

https://stovefanreviews.com/product/vulcan-stove-fan/

I may just get one myself now that I see they are available again. I don't expect that to last long.

I don't personally consider the price unreasonable. I've paid nearly as much for some small "toy" Stirling engines that have no functional use other than experimenting with.

[Tom Booth]

My criticism might be, it apparently requires direct surface contact with a good hot stove to operate. Probably something wider, like an LTD type design would have wider application on heaters with outer jackets or stoves that don't burn quite so hot.

I think I would like a wood stove fan that had a water reservoir to put some humidity in the air, as I usually keep a pot of water on the back of my wood stove for that purpose and there may not be room for both, and the water cooling would probably make the Stirling fan run better if used, but could still be optional.

Also, Vulcan does have a website, but they apparently do not sell direct:

https://www.vulcanfan.com/buy.asp

[aloneagain55]

Im located in America and was hoping to find a seller in my country instead of buying from overseas. Im wondering why these stirling stovew fans are priced high ? Its old technology and its not like it has complex components/electronics. If I could find 1 for $150 or so, Id probably give it a purchase, to see how it compares to my peltier/seebok woodstove fans , which have really come down in price over the years. I remeber 10-15 years ago, these peltier woodstovew fans were around $100 but now you can buy them new for around $25. I wish the stilring woodstove fans would have also came down in price like that.

I did just pruchase this $30 stirling unit to see if I can modify it to work on top of my woodstove. It may have been a waste of money/time , but for $30, I took a chance.

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[Tom Booth]

That is a Ringbom type Stirling, which, aside from the small size, I've often thought could be a good option for a wood stove fan or generator because the power output cylinder, in this case, the fan, is largely independent from the heat input cylinder, (in that engine, the glass displacer tube)

The two are joined by a flexible tube, so, at least in theory, could be separated.

For example, you could have a tall floor fan which could be positioned any which way as desired to direct the heat from the stove. If the wood stove had a removable cooktop lid, the heat input displacer cylinder could possibly drop down into the firebox.

If this was for a generator rather than just a fan, the generator with sensitive electrical components could sit on the floor some distance away from the stove.

To be practical, though, it would need to be scaled up a bit, I think.

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[Tom Booth]

A little better view of the connecting tube:

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It's not obvious because of the unified construction of this engine, but the displacer and power cylinder are actually only connected through the clear plastic tube, so if the engine were cut in half with a hacksaw, the fan could still operate with only the plastic tube connecting it to the heating displacer cylinder.

[aloneagain55]

I wonder if the top of a woodstove, gets hot enough to power this small $30 stirling fan I ordered ? Im guessing top of woodstove gets to be about 500 degrees F cause my stovepip 3-4 inchs from the top connection of my woodstove, gets to be 400-500 F regularly. I could always connect the displacer and power cylinder with copper tubing / heatproof tubing/hose.

[Tom Booth]

It's probably hot enough, though the engine is designed for a direct flame, which is pretty hot, so maybe not.

The problem though is you only want to heat the very end of the displacer cylinder. So, how to avoid heating up the rest of the engine at the same time?

Maybe poke the end of the glass tube through a small hole in the stove pipe?

It might also run tilted up on end with the end of the glass cylinder in direct contact with the stove, but then the fan would blow air up to the ceiling.

That type of Ringbom engine should run in any position, but it won't start if the whole engine is heated all at the same time.

[aloneagain55]

Heres a video of it running. Seems like it has good power and should certainly blow out alot more hot air then the seebook/peltier woodstove fans that only cost $25 or so.

Just have to figure out the best way to dissasemble this stirling fan so it works on a woodstove to get best heating of the tube and best cooling of the other end.

scroll down to 2nd link on left hand side of page to see video.

https://www.ebay.com/itm/305330751733?_ ... p_homepage

[Tom Booth]

I'm not able to locate the link you mentioned. Not in my phone browser anyway.

Just FYI, there was at one time a good size Stirling engine stove fan available from Canada for about $200 called Free Breeze.

As far as I know, though, they've gone out of business.

You can see the name "Free Breeze" on the top of this engine. It helps to pause the video.


https://youtu.be/KO7KhhNioTY?si=x3bEjLfmub2jgyuz

[aloneagain55]

Heres video of $30 stirling engine i bought and was hoping to modify to work on top of woodstove. Id love to hear any ideas on best way to do this modification. In this video, it seems like the fan moves alot more air then the normal $25 peltier stove fans.

click on ebay link and click on 2nd video on left.


https://www.ebay.com/itm/305330751733?m ... name=11051

[Tom Booth]

Heres video of $30 stirling engine i bought and was hoping to modify to work on top of woodstove. Id love to hear any ideas on best way to do this modification. In this video, it seems like the fan moves alot more air then the normal $25 peltier stove fans.

click on ebay link and click on 2nd video on left.


https://www.ebay.com/itm/305330751733?m ... name=11051

Thanks,

I'm not sure why, but on my phone it isn't apparent that the second image in the gallery thing is actually a video. No play button.

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In the video, that does appear like it might be more powerful than I had imagined.

If it were me, I think I would try using some copper tubing to transfer heat from the firebox to the engine. Put the glass heat tube or displacer end right inside the end of the copper tube, if it is a snug fit.

One time I needed to tend my wood stove and had misplaced the poker somewhere. I happened to have a 3 foot length of copper tubing so used that.

The instant the end of the copper tube touched some hot embers inside the stove, I had to drop the copper pipe as it would have seared my hand.

So, copper tubing is great for rapidly transferring heat and it could pretty much be shaped in whatever way necessary to go from inside the stove to wherever you want the fan.

For better efficiency and safety, the exposed parts of the copper tubing could be wrapped in something like muffler tape? Or some kind of heat resistant insulation blanket.

Anyway, that's what I'd try, and it really wouldn't require any modification to the engine.

[aloneagain55]

My sterling engine fan came oin today. Not impressed with it....the shaft that the propellor mounts to is either bent or the small bearing it rides on, is sloppy....Dont waste your money on this unit

[Tom Booth]

My sterling engine fan came oin today. Not impressed with it....the shaft that the propellor mounts to is either bent or the small bearing it rides on, is sloppy....Dont waste your money on this unit

Sorry to hear that. Unfortunately, typical of what's generally available on the market. Basically nothing useful or practical or reasonably priced.

I have plans for changing that, by setting up shop and building engines, but just now getting started and no products available yet, but I've made wood stove top fans and/or generators a top priority.

I have a half finished Myers fan, but just the castings cost hundreds of dollars:

https://myersengineworks.com/product/st ... sting-kit/

And that's without the fan blades and some other parts. Potentially a nice fan if you have a well equipped machine shop and a skilled machinist.

I'm leaning toward making low cost but high quality ceramic engines. Ceramic parts can be "cast" much like metal, (slip molds) but generally easier and less expensive.