Ecofan

[yamin]

Hi folks, Happy New Year!

Does anyone here use an Ecofan? We have a new Esse woodfired cooker (the enamelled one that looks like an aga). Its wonderfully warm and warming the whole ground floor, but there is one room we'd like to distribute a bit more heat too and I was wondering if Ecofans make a lot of difference to heat distribution?

Many thanks!

Yamin

 

[skier-hughes]

From what I've heard, two of my friends have them and love them, work well. But the cost!!!!!!!!!!!!!!!!!!!

 

[yamin]

Well yes, I can't see one for less than £90, but since we need no other heating at all, you could argue its worth the cost.......?

 

[AMc]

My folks have one of the 802 model on their woodburner which is in a deep chimney breast. When the stove hits temperature and it spins up it does shift heat out into a large room and it is silent in operation.

I'm not sure how far you're hoping to push the heat - it has to sit on a very hot surface to generate the electricity to drive the fan.
If a desk fan in the same location wouldn't work then I doubt it would help enough.

My folks have lent theirs to their neighbours to try as they're terribly enthusiastic about it. Perhaps you could get a try before you buy from a local supplier?

 

[biffvernon]

The Period model for heat distribution:

 

[Flyfisher]

Not very enviromentally-friendly though. Needs feeding and watering, not to mention economic suppression if it's not to develop aspirations of equality - goodness knows what the carbon-footprint implications would be.

A simple thermocouple and a small electric motor would seem to be far less trouble, providing they could be made cheaply enough by child labour somewhere. Hang on, I've got an idea . . . . .

 

[philpjuk100]

You must NOT stand punkawallas on logburners,they will soon burn out and smell bad!

 

[yamin]

Couldn't they stand on the log burner using the same psychological 'barrier' as those that manage to walk over hot coals??
Where is that dogs gramophone trumpet? Quick, someone stole it! A nice idea though Biff!

AMC, good idea. Plemty of heat on the surface of Esse to drive it, but as you say maybe we could find a way to try a more trad desk fan first as well to see if it works.

 

[skier-hughes]

I'm not sure how far you're hoping to push the heat - it has to sit on a very hot surface to generate the electricity to drive the fan.

Don't they just work off the heat rising from the burner? YOu need the heat to turn the fan, not to generate electricity to power the fan.

 

[Flyfisher]

Wouldn't that be a bit like using a big fan to power a sailing boat?

In any case, the Ecofan definitely uses electricity: http://www.ecofan.co.uk/technical-information.html

 

[yamin]

Ecofan definitely uses the heat to drive a small motor, clever eh?

 

[Penners]

Wouldn't that be a bit like using a big fan to power a sailing boat?

In any case, the Ecofan definitely uses electricity: http://www.ecofan.co.uk/technical-information.html

The website explains the science that powers the fan. As FF says, it's not just turned by warm air.

But their claim that the device "costs nothing to run" is an interesting one. Given that the fan requires energy to turn it, then the heat output of the stove will be reduced by the amount of energy consumed by the fan. So, if you want your stove to generate exactly the same amount of heat, you're going to have to burn more wood - which will cost more.

I appreciate that I'm talking small numbers, but isn't that the case?

 

[yamin]

Good point Penners. but I bake a cake each week for the local joinery in return for 5 sacks of rather gorgeous offcuts (shame to burn really!) - since we plan to take them all through the summer, we hope our wood stock will be high enough to only buy minimal wood next year. Guess it costs me the cake ingredients - 80p! No fuel as Esse on hot anyway! And NO central heating at all this winter!

 

[biffvernon]

But their claim that the device "costs nothing to run" is an interesting one. Given that the fan requires energy to turn it, then the heat output of the stove will be reduced by the amount of energy consumed by the fan. So, if you want your stove to generate exactly the same amount of heat, you're going to have to burn more wood - which will cost more.

I appreciate that I'm talking small numbers, but isn't that the case?

Nope. The energy used to turn the fan will end up as heat, in your room. Friction in the motor, friction between the moving air molecules, it all ends up as heat. It's the laws of thermodynamics that rule everything. Neither do you gain any heat by running one of these fans, though I suppose you might divert some warm air from convecting to the ceiling to more in your face.

 

[MdB]

But their claim that the device "costs nothing to run" is an interesting one. Given that the fan requires energy to turn it, then the heat output of the stove will be reduced by the amount of energy consumed by the fan. So, if you want your stove to generate exactly the same amount of heat, you're going to have to burn more wood - which will cost more.

I appreciate that I'm talking small numbers, but isn't that the case?

Come on Penners, back to school. Apply first law of thermodynamics.

edit - Extra points to Biff

 

[Delta]

This one looks more fun, and no electricity - http://www.gyroscopes.co.uk/d.asp?product=VULCANSTOVEFAN
Not cheap mind.

 

[Penners]

Friction in the motor, friction between the moving air molecules, it all ends up as heat.

Thus ends my brief career as a physicist.

But sir, please sir - what happens if the fan squeaks? Doesn't that use some of the energy to create sound rather than heat?

 

[Penners]

This one looks more fun, and no electricity - http://www.gyroscopes.co.uk/d.asp?product=VULCANSTOVEFAN

Aha - the dear old Stirling engine. An external combustion engine, if memory serves...

 

[JohnB]

Couldn't they stand on the log burner using the same psychological 'barrier' as those that manage to walk over hot coals??
Where is that dogs gramophone trumpet? Quick, someone stole it! A nice idea though Biff!

They could use a pedal operated fan. If they were slacking, their feet would get burned .

I think there is another make that I read was better and a bit cheaper than Ecofan, but I can't remember the name. It may be worth looking for alternatives.

 

[Flyfisher]

Thus ends my brief career as a physicist.

Not so fast.

In addition to your 'fan squeak' point (a noble clutch of a straw if ever I heard one :wink: ), what about the work involved in blowing a mass of air from one side of the room to another? That work must require a reasonable amount of energy, so not all of the heat energy collected from the stove by the thermocouple can be returned as heat by just the fan motor can it?

Or will someone argue that the displaced air is somehow heated up by frictional forces during its movement?