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Eco Fan


mrsmelly

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4 minutes ago, rusty69 said:

How can it be nondescript, with such a descriptive title? 

Perhaps  its an oxymoron (or oxyroaron) 

I had to look up the meaning of oxymoron!!! Bet some others did so too:). You're right. Nondescript but yet with such exciting other features. Shush......dont tell everyone, it will increase the bidding on Auntie Wainrights thread.

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On 09/12/2017 at 12:54, Dr Bob said:

By determining how much energy is transferred to the Nondescript cheap metal thing with the lion smoking a pipe,a flaming tail, a head like Oliver Cromwell and extremely short back leg, I can then predict the likely heat flow into the Ecofan ( but mine isnt an Ecofan) and thus how much additional heat is transferred to a point 3.1M away and 0.5M below from said fan.

 

This is to fundamentally misunderstand the function of an ecofan. It does not transfer heat energy collected by conduction up the leg. 

A stove when hot warms the air around it, and this air naturally rises to the ceiling where it stratifies. Hottest air at the top, and coldest air at the floor. In a quiet boat (with say, some bloke just sitting still watching telly or typing furiously into a laptop), this stratification effect becomes remarkably severe. I can have 35C at my ceiling and 15C on the floor. The Ecofan disrupts this effect to a degree by stirring up the hot air rising from the stove.

The heat energy rising up the leg powers the Peltier cell and is converted to electrical energy to drive the fan which stirs up the air so there really is no point in trying to measure or determine the power being picked up by the Ecofan leg. 

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22 minutes ago, Mike the Boilerman said:

 

This is to fundamentally misunderstand the function of an ecofan. It does not transfer heat energy collected by conduction up the leg. 

A stove when hot warms the air around it, and this air naturally rises to the ceiling where it stratifies. Hottest air at the top, and coldest air at the floor. In a quiet boat (with say, some bloke just sitting still watching telly or typing furiously into a laptop), this stratification effect becomes remarkably severe. I can have 35C at my ceiling and 15C on the floor. The Ecofan disrupts this effect to a degree by stirring up the hot air rising from the stove.

The heat energy rising up the leg powers the Peltier cell and is converted to electrical energy to drive the fan which stirs up the air so there really is no point in trying to measure or determine the power being picked up by the Ecofan leg. 

This is how I understand the ecofan. The heat in the legs is to create the electricity to drive the fan. A tiny amount will escape the legs by convection, (and be projected by the fa), but it is not significant, and not required by the design.

Once the fan is running, it sucks some of the rising warm air from behind itself, and projects it into the space at fan level.

My experience is that this projection is enough to flutter a piece of A4 paper about a foot away, and MtB has a more scientific gizmo which shows something more specific.

As the typical bloke, sitting still or typing furiously, I sense no difference in stratification with the fan running, or not running.

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43 minutes ago, Mike the Boilerman said:

A stove when hot warms the air around it, and this air naturally rises to the ceiling where it stratifies. Hottest air at the top, and coldest air at the floor. In a quiet boat (with say, some bloke just sitting still watching telly or typing furiously into a laptop), this stratification effect becomes remarkably severe. I can have 35C at my ceiling and 15C on the floor. The Ecofan disrupts this effect to a degree by stirring up the hot air rising from the stove.

The heat energy rising up the leg powers the Peltier cell and is converted to electrical energy to drive the fan which stirs up the air so there really is no point in trying to measure or determine the power being picked up by the Ecofan leg. 

No I fully understand what you are saying and I fully agree with it - as I have been saying all along - which is why my feet are nice and warm with the Ecofan (which isnt an Ecofan) without getting the boat to 27°C (it worked again!) as a certain person on this thread has to do. I indicated "transfer heat energy collected by conduction up the leg" as a simplified way to describe the technicalities of what is going on in laymans terms, so those who havent a clue (and the unbelivers) can keep up.

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40 minutes ago, Dr Bob said:

No I fully understand what you are saying and I fully agree with it - as I have been saying all along - which is why my feet are nice and warm with the Ecofan (which isnt an Ecofan) without getting the boat to 27°C (it worked again!) as a certain person on this thread has to do. I indicated "transfer heat energy collected by conduction up the leg" as a simplified way to describe the technicalities of what is going on in laymans terms, so those who havent a clue (and the unbelivers) can keep up.

Spot on, what I've said too. But I also consider , because it increases the airflow around the stove, it takes more heat from the stove that would normally go up the chimley. Hence the effect on my kettle. Maybe it's more effective on my stove at home because the stove is sitting in a hole with a 4" gap at sides back and bottom, 12" above. 

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7 hours ago, Jim Riley said:

Spot on, what I've said too. But I also consider , because it increases the airflow around the stove, it takes more heat from the stove that would normally go up the chimley. Hence the effect on my kettle.

Nope. It’s stopping your kettle from boiling because it’s acting as an effective heat sink, pulling the heat from the top plate and dissipating it from the fins. (Four times).

It’s easy to prove; disconnect one of the wires to the fan and you’ll witness exactly the same effect. 

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37 minutes ago, WotEver said:

Nope. It’s stopping your kettle from boiling because it’s acting as an effective heat sink, pulling the heat from the top plate and dissipating it from the fins. (Four times).

It’s easy to prove; disconnect one of the wires to the fan and you’ll witness exactly the same effect. 

Your all wrong, its cause he's now watching the kettle

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On 08/12/2017 at 12:34, Jim Riley said:

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. 

Actually I am a doubting engineer and I refer you to my post about keeping a kettle just below boiling point by placing a non-rotating flat iron on the hotplate.

When tea is required the iron was removed and the kettle began to boil almost immediately.

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4 hours ago, carlt said:

Actually I am a doubting engineer and I refer you to my post about keeping a kettle just below boiling point by placing a non-rotating flat iron on the hotplate.

When tea is required the iron was removed and the kettle began to boil almost immediately.

By but but, of course that will only work until the flat iron comes up to temperature, it not having fins cooled by a fan. Another pan of water would have the same effect, better use of the heat. Unless you actually want to use the flat iron.

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13 minutes ago, Jim Riley said:

By but but, of course that will only work until the flat iron comes up to temperature, it not having fins cooled by a fan. Another pan of water would have the same effect, better use of the heat. Unless you actually want to use the flat iron.

Nope. Once again you are missing the obvious point of greater surface area. That’s why the Ecofan stops your kettle from boiling (tried my simple test yet?), the increased surface area of the cooling fins. And that’s why the flat iron does the same thing. 

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1 hour ago, Jim Riley said:

By but but, of course that will only work until the flat iron comes up to temperature, it not having fins cooled by a fan. Another pan of water would have the same effect, better use of the heat. Unless you actually want to use the flat iron.

but but it worked for a decade as a heat sink with or without fins or a practically powerless fan.

You try it if you want to dismiss my experience. 

I had an ecofan and gave it away. 

I still have the flat iron.

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12 hours ago, carlt said:

You try it if you want to dismiss my experience. 

Dismiss? Aw didums! Such emotive language for a scientific debate.  No, I question! Here, have a tissue, dry your eyes now lad!

The capacity to act as a heatsink is down to the mass of the object, the capacity of that mass to disperse the heat as it accumulates is down to its surface area, colour and air moving across it. So we have a solid flat iron lump and a skinny funny lump with a greater surface area and a steady breeze blowing across it, which do you rationally assume would disperse accumulated heat quicker?

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45 minutes ago, Jim Riley said:

Dismiss? Aw didums! Such emotive language for a scientific debate.  No, I question! Here, have a tissue, dry your eyes now lad!

Scientific debate? 

I thought we were having a light hearted debate amongst laymen keeping the science well below 'o' level standards. 

Yes you are probably right that a flat iron with vanes would be better at stopping the kettle boiling but a fan with less force than a mouse's fart behind it would not warm a cabin up any quicker. 

I have already discussed the test I did with the ecofan in an insulated open hold which led to me giving it away (to someone who did drink the koolade and swears by it to this day) so I won't bother again as it was noted by the sceptics and dismissed by the believers as expected so the "science"  is pretty irrelevant. 

Try not to overreact to harmless words like "dismiss"  though. Let's keep it lighthearted. 

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1 hour ago, carlt said:

Scientific debate? 

I thought we were having a light hearted debate amongst laymen keeping the science well below 'o' level standards. 

Yes you are probably right that a flat iron with vanes would be better at stopping the kettle boiling but a fan with less force than a mouse's fart behind it would not warm a cabin up any quicker. 

I have already discussed the test I did with the ecofan in an insulated open hold which led to me giving it away (to someone who did drink the koolade and swears by it to this day) so I won't bother again as it was noted by the sceptics and dismissed by the believers as expected so the "science"  is pretty irrelevant. 

Try not to overreact to harmless words like "dismiss"  though. Let's keep it lighthearted. 

Don't worry, I am, it's banter. Except for the bit about ecofans actually working. 

However if my experience shows it works and yours shows it doesn't, what else is there but the actual facts, determined by science.

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8 minutes ago, Jim Riley said:

Don't worry, I am, it's banter. Except for the bit about ecofans actually working. 

However if my experience shows it works and yours shows it doesn't, what else is there but the actual facts, determined by science.

Fair enough...

My experience was a fairly thorough experiment involving an open plan under-tarp conversion with a professional standard temperature probe carried out by an obsessive Materials Research Engineer.

I found negligible difference in temperature gradients with or without the Ecofan (sometimes better with, sometimes better without) but one stark difference I found was when I had the hold door spy hole open (about 1.5" diameter) and the front deck hatch wedged open a fraction which created enough draught to even out the temperature throughout the 45' cabin though opening the side windows stirred it all up again.

One thing that did surprise me though was that I found very little effect from the computer fan fixed to the ceiling above the stove which I expected to outperform the Ecofan.

Of course my results can be rubbished just as easily as the ones mentioned 20 odd pages ago....How many of you live in a 45' open plan cabin for a start....

What really swung it for me though was that opening the spy hole was silent unlike the persistent whirring blades announcing "Look at me! I'm doing sweet F.A. really noisily!".

 

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