Heat driven fans for woodstoves

[Phil Pascoe]

This was touched on in another thread. Has anyone built one of these fans? It cannot be complicated, can it? They seem to fetch silly money for what they are.

 

[Bod]

The trick is to get a heat differential across the Peltier unit. Or very good engineering for a Stirling engine one.
Put "stove top fan" into Google and the choice is yours!
Current price for ours, is now less than 1/2 it was 5 years ago.
Your stove top must be flat, not angled as some bigger ones are.

Bod

 

[bugbear]

This was touched on in another thread. Has anyone built one of these fans? It cannot be complicated, can it? They seem to fetch silly money for what they are.

They're very simple, but I don't think you could buy:

* peltier generator
* large heatsink
* motor
* fan
* nice looking frame

for much less than the cost of the finished item. I suspect the peltier is the major cost.

BugBear

 

[Phil Pascoe]

I've just googled peltier generator - I'm out of my depth already. :lol:

 

[Bod]

Stove fans are common in inland waterways boats, folk there seem to fall into one of two camps, best thing since sliced bread, or pure snake oil.
All agree that they are a good indicator of how well the fire is burning, blades barely moving = more fuel, going like the clappers = close the damper.

Bod
(Who knows they make a difference.)

 

[porker]

I've got one on my recently installed stove. Got good reviews and was about £45 if I remember. Our stove is in a fireplace and I wanted the heat to be pushed out a bit better into the room. The problem I have is I have 9' ceilings and the room is fairly open plan so the heat rises to the ceiling and largely disperses. The fan works and spins quite fast but be aware that the airflow is very low. In no way does it compare with an electric fan. With your hand a few inches in front of the fan you will barely feel any flow. However, comparing with and without the fan it has improved the heat distribution but you need to be realistic about the difference it will make.

 

[Bm101]

https://www.youtube.com/watch?v=g3fHGIPFqpY

This might help. Got a parts list at the end.

 

[Phil Pascoe]

Very interesting - I think it's put me off already.
Looking at mine, I need to blow heat out of the room, so an electric one makes far more sense. It's a bungalow, so I might insulate a duct through the roof down into another room and put a 6" fan in the ceiling. It would only have to 7' or 8' feet long. I don't want to get into central heating systems - it's a small place.