Looking for stove fan recommendations

[John Skinner]

33 minutes ago, doobin said:

I'm going the whole hog this winter. I'm going to wrap some flexible steel 6" duct around the stove, then couple this to a 6" inline blower. This I will couple ten metres of normal plastic flexi duct to, and suspend up the banisters to the top of the house.

 

Will look gash but so would the gas bill otherwise.

 

Aye. I don't think you'll be the only one coming up with homemade solutions to the heat problem. I just put in a new gas boiler/system in June and already have the bugger turned off for all but hot water. NO WAY i'm forking out 3, 4, .., 7 times the normal price for gas to heat this place. It's all going to be logs in the stove from now on. The neighbours trees might all vanish but i will be nice and warm ... i hope.

[openspaceman]

2 hours ago, doobin said:

I'm going the whole hog this winter. I'm going to wrap some flexible steel 6" duct around the stove, then couple this to a 6" inline blower. This I will couple ten metres of normal plastic flexi duct to, and suspend up the banisters to the top of the house.

 

Will look gash but so would the gas bill otherwise.

I cannot see that as being necessary as hot air rises up the stairs anyway, it is getting it distributed on the ground floor where a fan comes in handy,

Edited August 29, 2022 by openspaceman

[Steven P]

As above, my first fan was a £50 one from an online store, the next one is a £18 (I think) Aldi one, both stove top fans, and both about the same, I noticed the difference when the first one stopped but not necessarily when I bought it. A slow steady jet of air coming out the fire place, point the fan at the living room door and it sort of sends it to the hall to go upstairs.

 

I reckon the stove top fans at this price the thermoelectric generator are vey similar, and the difference will be the heat sink and fan design. The greater the temperature difference the more power you get from it... so a larger heat sink and a better fan design sends more hot air out. However I don't know how many of these are designed by professors in thermodynamics and how many are designed by a Chinese man (mostly made in China), scrap of paper and put together it sort of works. I suspect there are more Chinese men making these than there are professors.

 

If you want you can get a basic fan and heat sink and spend the same again to get an upgraded generator for a little more power (I haven't yet, got the old one to do that with sometime), and even more power? Try thinking of a water cooler for the 'cold' side but that is going a little far I think

 

 

My next one will be a Sterling engine fan just for the aesthetics.

[difflock]

Surely natural convection currents will move more air, than any affordable to run fan?

When we lived in the living room, if I were sitting in the bay window, about 5 m away from the stove, I could feel the draught of warm** air falling down and recirculating. Or at least that was my preception.

It could have been nearing 30 deg at the ceiling so the air was still "warm" despite being cooled by the glass.

And my thinking would be to fit a ceiling fan to drive the heat back down from the ceiling/prevent stratification.

[openspaceman]

1 hour ago, Steven P said:

 

My next one will be a Sterling engine fan just for the aesthetics.

Yeah I would go on a Stirling engined one  just for that reason but don't use my peltier one anymore.

[openspaceman]

51 minutes ago, difflock said:

Surely natural convection currents will move more air, than any affordable to run fan?

Actually the circulation due to buoyancy is quite small so a very low power fan can have a big effect, think why hot air balloons are so much bigger than helium ones.

51 minutes ago, difflock said:

 

And my thinking would be to fit a ceiling fan to drive the heat back down from the ceiling/prevent stratification.

I have a ceiling fan, mostly used for circulation on hot days but we did use it to de stratify the air when the wood burner was in that room.  The instructions were to reverse the flow when using it to de stratify but we found it better just to blow down,

[doobin]

18 hours ago, openspaceman said:

I cannot see that as being necessary as hot air rises up the stairs anyway, it is getting it distributed on the ground floor where a fan comes in handy,

The problem is getting it out of the low doorway.

 

That's why in other countries you see cutouts in walls just under the ceiling.

[openspaceman]

9 hours ago, doobin said:

The problem is getting it out of the low doorway.

 

That's why in other countries you see cutouts in walls just under the ceiling.

Ah I see.

[neiln]

I've read/seen on YouTube loads of times that blowing cool air toward the stove top displace the warm, is more effective than blowing the warm.  Presumably because it's denser.  Also to stop stratification in a room, a large floor fan pointing upwards will mix the air up in just a few minutes.

 

I use the stove fans, I've had a valiant but it's no better than £20 or less ones from eBay.  I think they help get heat out of a tight fireplace but not much more.  Likewise I'd love a Stirling engine fan but they are too tall for my available space.... And a bit costly.

[sandspider]

I have a couple of the cheaper stove fans, £30 ish. They do move some air, especially from the stove which is tucked into an old fireplace. They certainly don't do any harm, nor cost electricity like a mains fan. I'd be interested to compare one of the pricey Caframo fans to see if they're any better - but I doubt they'd do 3 x better than the £30 jobs.