Non-Stove Top Fan

[Moxi]

DIY something like this maybe

https://www.amazon.com/Exchanger-Output ... B0180YVXTO

other styles shapes materials and patterns galore on a google search for stove pipe heat exchanger

Moxi

[Joeboy]

That is cool!

I.guess the heat is drawn quicker through surface to air radiation on the fins. I wonder how much more than off the unfinned pipe area? Regardless, cool!

DIY something like this maybe

https://www.amazon.com/Exchanger-Output ... B0180YVXTO

other styles shapes materials and patterns galore on a google search for stove pipe heat exchanger

Moxi

[openspaceman]

That is cool!

Not too cool that the flue gas temperature falls below its dewpoint I hope.

[ecogeorge]

Maybe couple it with a fan for maximum effect ?
Create the worlds first condensing woodburner
George.

[Joeboy]

That is cool!

Not too cool that the flue gas temperature falls below its dewpoint I hope.

Are we talking cooling pipes, nasties condensing out of flue gase and with corrosive properties to burn into the liner? Would not have thought of that if you hadn't said. It's all a balance eh?

[Oliver90owner]

If the surface of the aga/rayburn/wbs was too hot, I think I would stand the usual peltier fan on a trivet of some description. Not seen a cooked TEG on one of these yet (I’ve not got one) but have replaced the fan motors a couple or three times.

[Joeboy]

If the surface of the aga/rayburn/wbs was too hot, I think I would stand the usual peltier fan on a trivet of some description. Not seen a cooked TEG on one of these yet (I’ve not got one) but have replaced the fan motors a couple or three times.

We have a good surface contact on top of wbs with one fan currently. I think I'll be buying a flue fan as its running at 95 degrees. Will measure up tomorrow when flue is cool, see what's out there at that size.

[openspaceman]

That is cool!

Not too cool that the flue gas temperature falls below its dewpoint I hope.

Are we talking cooling pipes, nasties condensing out of flue gase and with corrosive properties to burn into the liner? Would not have thought of that if you hadn't said. It's all a balance eh?

Yes a woodburner is different from a condensing gas boiler, where you want the flue gases to cool below their dew point (about 50C) in order to get some benefit from the latent heat as water droplets form, with wood you need the exhaust to staay above the water boiling point as it vents, otherwise the vapours condense and run back down, as happens if you burn wet wood. With a conventional brick chimney the pyroligneous acid can rot the chimney lining, with a stainless steel liner it can etch into the chromium oxide layer exposing iron molecules to oxidation. I have seen this on a large commercial boiler which was being used to incinerate reject flat pack furniture at a well known swedish store, the glues and such probably increased the corrosion but a single skinned EGR pipe was riddled with pinholes.

I run my flue at 150-200C which is too high for a flexible lined flue but mine is concrete lined and the heat the chimney absorbs is given off overnight once the fire is out and it keeps the downstairs and a bedroom above warm. A thermal camera clearly shows the effect.

[openspaceman]

If the surface of the aga/rayburn/wbs was too hot, I think I would stand the usual peltier fan on a trivet of some description. Not seen a cooked TEG on one of these yet (I’ve not got one) but have replaced the fan motors a couple or three times.

The one I used to use had a bimetallic strip in the base which tilted the whole unit over and the air gap created decoupled the hot side of the Peltier effect module from the hot surface.

[Joeboy]

If the surface of the aga/rayburn/wbs was too hot, I think I would stand the usual peltier fan on a trivet of some description. Not seen a cooked TEG on one of these yet (I’ve not got one) but have replaced the fan motors a couple or three times.

The one I used to use had a bimetallic strip in the base which tilted the whole unit over and the air gap created decoupled the hot side of the Peltier effect module from the hot surface.

Spread the love? Got a make or link OSM? I don't particularly want to buy into a stove top safety.switch for the fan but can appreciate the elegance of design.

I'll hunt about for a nice twin flue mounted quiet well built unit. Although I'll be flue OD driven. I'm looking for max heat transfer so a snug fit with mucho surface area contact is a prerequisite. I wonder who I know with a tig welder? Could bastardise a cheap commercial twin fan unit into what I'd like.