Eco Fan

[Rob-M]

Depends what you are typing on,, on my tablet have to go to the second page of symbols on the Google keyboard and then I have a ° key.

 

[Jerra]

14 minutes ago, Dr Bob said:

Cor you're clever. How do you do the degrees symbol? Been wondering that for ages?

On my computer you type ALT 0176 holding the ALT key down all the time.  However it doesn't seem to work on the forum it just jumps me to the forums page.  Strange.

In most other things I use all ASCII characters can be displayed by holding ALT and typing the required number.

[Dr Bob]

4 minutes ago, Rob-M said:

Depends what you are typing on,, on my tablet have to go to the second page of symbols on the Google keyboard and then I have a ° key.

 

I am on a macbook pro at the mo....and no idea.

how do you get the google keyboard up on the tablet?

Just now, Jerra said:

On my computer you type ALT 0176 holding the ALT key down all the time.  However it doesn't seem to work on the forum it just jumps me to the forums page.  Strange.

In most other things I use all ASCII characters can be displayed by holding ALT and typing the required number.

Thanks for that, I will try it.

[MtB]

2 hours ago, mross said:

We engineers have tried these stove fans and looked for evidence of any benefit.  We did not find it.  

 

Well I consider myself an engineer and I repeatedly describe here the benefits I find in mine.

They are nice things to have around, a bit like a cat purring on the sofa. And mine gives me a continuous audio commentary on the state of the stove so I know in advance when I need to add coal, rake it out etc without having to go and look at it periodically. The Stirling engine fans are even nicer, chuffing away quietly on the stove like a little steam engine!

In addition I perceive the comfort levels in the boat to be improved even though I grant you measurements with a thermometer would probably show no change to air temp. Air movement can be demonstrated though using a smoke pen or the smoke trail from an incense stick. 

 

[Rob-M]

20 minutes ago, Dr Bob said:

I am on a macbook pro at the mo....and no idea.

how do you get the google keyboard up on the tablet?

Thanks for that, I will try it.

I am using an Android tablet which has the Goggle keyboard as the default input device.  You can install additional keyboards from the Play Store and then switch between them in Settings\Language & Input.

Googling How to type a degree symbol comes up with...

 

1. On PCs - hold down the Alt key and on the numeric keypad on the right of the keyboard, type 0176, or Alt+ 248 When you release the Alt Key, a ° should be there.
2. On Macs - option shift 8

[Dr Bob]

1 minute ago, Rob-M said:

I am using an Android tablet which has the Goggle keyboard as the default input device.  You can install additional keyboards from the Play Store and then switch between them in Settings\Language & Input.

Thanks Rob, I will try it.

[mross]

14 minutes ago, Mike the Boilerman said:
Air movement can be demonstrated though using a smoke pen or the smoke trail from an incense stick. 


Have you tried this with fan off?  The air movement may actually be caused by convection.  You seem to agree that the temperature doesn't change!

 

Edited December 8, 2017 by mross

[Machpoint005]

1 hour ago, Rob-M said:

Depends what you are typing on

That's why I use a Windows laptop with a numeric keypad!  

1 hour ago, mross said:

Have you tried this with fan off?  The air movement may actually be caused by convection.

Or people or animals moving around.

[Jim Riley]

No doubting engineer has answered my evidence, they've ignored the because it doesn't suit their world view. 

With ecofan on stove kettle won't boil, without ecofan it will. So the fan is taking heat from the stove that would otherwise go up the chimney or heat the kettle. Who has robbed the joules otherwise, where have they gone??Also a static thermometer wouldn't demonstrate that there is a more even distribution of heat around a room, test the effect in the cold spots. 

[mross]

Whether your kettle boils or not does not prove that the Ecofan spreads heat around a boat.  It may suck some heat of the stove top and into the air above the stove.  Probably any lump of metal with fins on it, but no fan, would do the same.

An Ecofan motor produces about 1 Watt.  The TEG module is very inefficient - maybe around 5%.  So it might take 20 Wats from the stove.  Your stove is probably about 4kW - that's 4,000 Watts.  So the effect on your kettle is minimal.  The temperature drops from 100 to 99 it WILL stop boiling.

Edited December 8, 2017 by mross

[Jim Riley]

Probably? Probably pigs can fly. Any fule kno that air moving across a surface increases the exchange of heat, into or from that surface, depending on the temperature difference between the two. And you've avoided the question, where have the joules gone?

[mross]

I did say where I thought the joules had gone; read it again.  

[Jerra]

3 minutes ago, mross said:

I did say where I thought the joules had gone; read it again.  

As I read it you are suggesting the joules go into the metal, true.  However they don't keep piling up making the metal hotter than the stove so where do they go?

[Dr Bob]

14 minutes ago, Jim Riley said:

Probably? Probably pigs can fly. Any fule kno that air moving across a surface increases the exchange of heat, into or from that surface, depending on the temperature difference between the two. And you've avoided the question, where have the joules gone?

Jim, I'm not sure how many of the previous 16 pages you have read but you are going to struggle to convince any of the Ecofan doubters under ANY circumstances. The Canadian University report claimed that Ecofans saved 15% in fuel usage yet the unbelievers aren't even willing to accept any temperature changes let alone a benefit to their pockets. On close scrutiny the methodology of the paper seemed sound.

Mrs Melly who started the thread runs his boat at 27°C (hey it works!!!!) so he is never going to see a difference. Others are using Aldi or other Chinese copies that will be as good as chocolate tea pots. For the rest, they are probably a lot less sensitive to heat than those of us believers. I can feel a couple of degrees of heat difference between head and feet. I suspect many can not.

Anyway, lets not get too tangled up in facts. They will only get in the way. This thread still has another 16 pages to run. Just wait until I set up my killer test in a few weeks time.

[Jim Riley]

OMG! My stove has gone molten. I've fed it too much Jet and other joules. they've built up in the metal.

[Jim Riley]

11 minutes ago, Dr Bob said:

Jim, I'm not sure how many of the previous 16 pages you have read but you are going to struggle to convince any of the Ecofan doubters under ANY circumstances. The Canadian University report claimed that Ecofans saved 15% in fuel usage yet the unbelievers aren't even willing to accept any temperature changes let alone a benefit to their pockets. On close scrutiny the methodology of the paper seemed sound.

Mrs Melly who started the thread runs his boat at 27°C (hey it works!!!!) so he is never going to see a difference. Others are using Aldi or other Chinese copies that will be as good as chocolate tea pots. For the rest, they are probably a lot less sensitive to heat than those of us believers. I can feel a couple of degrees of heat difference between head and feet. I suspect many can not.

Anyway, lets not get too tangled up in facts. They will only get in the way. This thread still has another 16 pages to run. Just wait until I set up my killer test in a few weeks time.

I know all about the infidels, but thats no reason not to poke them with the stick of truth. Hopefully you will get a bigger stick, if not a battering ram. Even then, I suspect some are too far gone to admit even the tiniest of benefits. 

[Machpoint005]

1 hour ago, Jim Riley said:

So the fan is taking heat from the stove that would otherwise go up the chimney or heat the kettle. Who has robbed the joules otherwise, where have they gone?

Into the metal of the stove, then into the surrounding air, mainly by convection, which happens with or without an Ecofraud device. If the device takes 1W to drive it, the number of 'missing' joules is within the range of experimental uncertainty. Even if they went up the chimney (which they don't) it would not be a measurable quantity.

Yes, I am an Engineer.

27 minutes ago, Jim Riley said:

I know all about the infidels

Your choice of terminology is revealing. This isn't a matter of faith. 

44 minutes ago, Dr Bob said:

Anyway, lets not get too tangled up in facts. They will only get in the way.

[mross]

41 minutes ago, Dr Bob said:

Anyway, lets not get too tangled up in facts. They will only get in the way.

Ha-ha.  Facts will get in the way!    

[mross]

33 minutes ago, Jim Riley said:

some are too far gone to admit even the tiniest of benefits. 

I admit the Ecofan has some benefits

• it transfers money to caframo
• it looks nice
• it moves a tiny and insignificant amount of air, but not far

1 hour ago, Jim Riley said:

And you've avoided the question, where have the joules gone?

Jim, as I said, "It may suck some heat of the stove top and into the air above the stove."

[Jim Riley]

37 minutes ago, mross said:

I admit the Ecofan has some benefits

• it transfers money to caframo
• it looks nice
• it moves a tiny and insignificant amount of air, but not far

Jim, as I said, "It may suck some heat of the stove top and into the air above the stove."

The air above the stove is moving faster than by convection. It's moving horizontally. Away from the stove. Taking the heat with it. So cool  air is constantly being drawn in  to replace it. That is then warmed and blown away. Constantly but slowly. Cooling the stove. So the kettle doesn't boil.

By your reckoning the effect of a static fan on the kettle would be the same as the moving fan. This is not the case. Kettle boils.

Btw an insignificant force, applied continuously, can move mountains. A little drip in same place, wears a big hole. 

At least you now agree there is some effect, that there is a force.

Edited December 8, 2017 by Jim Riley

[Jim Riley]

Dear anyone know how to calculate how much fluid a propellor moves, at a given speed, size and pitch? This would tell us how much air an ecofan can shift. Any engineers got a book of tables?

[mross]

20 minutes ago, Jim Riley said:

At least you now agree there is some effect, that there is a force.

Jim, you seem to think I have changed my position, I haven't.  The fan spins, it moves a little air.  What I have said and repeat is that what it does is insignificant.  It's like those desk fans or coffee heaters that can be powered from a USB plug (except that a USB plug can belt out 2.5 Watts  )

[mross]

20 minutes ago, Jim Riley said:

Dear anyone know how to calculate how much fluid a propellor moves, at a given speed, size and pitch? This would tell us how much air an ecofan can shift. Any engineers got a book of tables?

It is not that simple because air is a fluid and the fan does not produce a uniform block of moving air.  Some of the air travels outwards and back into the suction side.  You could calculate the theoretical maximum if you know the developed blade area, the angular pitch of the blades and the speed of rotation.  The actual flow might be only half of this.  Or you could use one of those portable anemometers that sailors have and measure the speed of air immediately in front of the fan and use the area of the circle that contains the fan blades.

Jim, please supply details of your planned experiment and I will critique it in a friendly and helpful way so that it satisfies the cynics.  Cheers!

[Dr Bob]

37 minutes ago, Jim Riley said:

Dear anyone know how to calculate how much fluid a propellor moves, at a given speed, size and pitch? This would tell us how much air an ecofan can shift. Any engineers got a book of tables?

Caframo, the makers of Ecofan say their 800 model, used in the Universtity tests, move circa 150 cubic feet per minute. With the diameter, you can then calculate the velocity coming off the blades. My 2017 Ecofan from Caframo is claimed to have a higher throughput of 265 Cubic feet per minute (IIRC) and has a blade diameter of 9''. Maybe it is the higher throughput I am feeling. It is certainly moving more air towards me than upwards. If you measured the velocity of the rising air from the stove, without a fan, I think that velocity would be significantly lower than than velocity created by the fan, even if the fan velocity is very low and half of it goes back round again. Therefore it breaks the normal convection flow and helps prevent stratification but doesnt get the air to the back of the boat unless you try it with essential oils ....and it saves you 15% of fuel costs.

edit - to add the bit about air going round a second, third and forth time as per Mross's comments

7 minutes ago, mross said:

 

Jim, please supply details of your planned experiment and I will critique it in a friendly and helpful way so that it satisfies the cynics.  Cheers!

I think a realistic test without using a giant rubber duck and Nondescript cheap metal thing with the lion smoking a pipe,a flaming tail, a head like Oliver Cromwell and extremely short back leg is going to be fraught with problems.

Edited December 8, 2017 by Dr Bob

[mross]

A small Xpelair bathroom exhaust fan, rated at 750 Watts has a flow of 0.02 cubic metres per second.  This is 42 CFM.  Do you wonder why I am cynical when Ecofan claim their 1 Watt fan can move 175 CFM?

https://www.xpelair.co.uk/assets/xpelair/brochures/Xpelair-Ventilation-Guide.pdf

http://www.ecofan.co.uk/woodstove-ecofans.html