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Using an Ecofan the wrong way?

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7 hours ago, Keeping Up said:

Surely the kinetic energy is converted into thermal energy as the moving air slows down and stops

 

Of course it is.

11 hours ago, blackrose said:

the transformation into kinetic energy may result in those convection currents increasing

If there is more air moving about, it isn't because of convection, it is because of the fan.

 

11 hours ago, blackrose said:

Any losses in heat output from the stove to run the fan

 

There aren't any. The stove produces the extra energy by burning more fuel. You have an open system masquerading as a closed system. I agree that the differenes may be small, but then so are the changes you are claiming.

 

An increase in output does not necessariy indicate mean there is an increase in efficiency, as any fule kno.

 

 

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After reading this thread I think I am going to rip out the two stoves and whispergen and install ecofans powered by candles as they will work far better than what I have got ?

ig bag of popcorn?

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5 minutes ago, peterboat said:

After reading this thread I think I am going to rip out the two stoves and whispergen and install ecofans powered by candles as they will work far better than what I have got ?

ig bag of popcorn?

There is an even better and safer way. You know those hand warmers that you put liter fluid in and they keep yer hands warm for ages? I have one. All you do is set that going and rest an eco fan on top of it and my 68 footer will maintain a steady 30 degree temperature on one filling of liter fuel for 48 hours.

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3 hours ago, peterboat said:

After reading this thread I think I am going to rip out the two stoves and whispergen and install ecofans powered by candles as they will work far better than what I have got ?

ig bag of popcorn?

You are not thinking big enough. Rip out those silly batteries you have and instal a wood powered sustainable tree growing powered barbecue on the stern. Two ecofans super glued ( careful h and s  issue here) to the top.

fire up. Cook tea and boat on the tornado like wind power.

if you insist on that now obsolete electrical propulsion unit ( so last month) you and have another fan reverse rotation on the bow connected to the alternator. Thus producing power as you brake coming to locks.

 

im looking forward to the wood powered tesla . We could make it autonomous by putting it on two parallel steel rails in the absence of electricity. If we fastened them together it would be even better.

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13 hours ago, roland elsdon said:

You are not thinking big enough. Rip out those silly batteries you have and instal a wood powered sustainable tree growing powered barbecue on the stern. Two ecofans super glued ( careful h and s  issue here) to the top.

fire up. Cook tea and boat on the tornado like wind power.

if you insist on that now obsolete electrical propulsion unit ( so last month) you and have another fan reverse rotation on the bow connected to the alternator. Thus producing power as you brake coming to locks.

 

im looking forward to the wood powered tesla . We could make it autonomous by putting it on two parallel steel rails in the absence of electricity. If we fastened them together it would be even better.

I have just installed a bigger bank, so I will follow your sdvice and flog them on and buy super ecofans! The only issue I can think off is massive bow waves from me and the water skiers, so maybe with hydra foils the fans could get me up onto the plane?

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1 hour ago, roland elsdon said:

Dont follow my advice... just drove a tesla yesterday totally underwhelming. Now looking for a 1937 car to match boat. I think up grading is over rated.

I bet it went faster than Peter's ecofan powered fat boat.

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3 hours ago, roland elsdon said:

Dont follow my advice... just drove a tesla yesterday totally underwhelming. Now looking for a 1937 car to match boat. I think up grading is over rated.

I have driven 2 model a p100d teslas and I found them anything but underwhelming! 0 to 60 in just over 2 seconds is changing underpants stuff   and I have had a shelby mustang and vette ZR1 the Tesla made them look slow 

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11 hours ago, roland elsdon said:

Dont follow my advice... just drove a tesla yesterday totally underwhelming. Now looking for a 1937 car to match boat. I think up grading is over rated.

I have almost the perfect thing to match your boat, a 1937 Armstrong Siddeley, Siddeley Special. Just returned to the road after being laid up since 1966ish. A heater and power steering would be a welcome upgrade though.

20191005_111921.jpg

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1 hour ago, p6rob said:

I have almost the perfect thing to match your boat, a 1937 Armstrong Siddeley, Siddeley Special. Just returned to the road after being laid up since 1966ish. A heater and power steering would be a welcome upgrade though.

20191005_111921.jpg

I might have mentioned before quite how lovely she is but what makes her a special, what was added over the normal none special model?

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1 hour ago, p6rob said:

I have almost the perfect thing to match your boat, a 1937 Armstrong Siddeley, Siddeley Special. Just returned to the road after being laid up since 1966ish. A heater and power steering would be a welcome upgrade though.

20191005_111921.jpg

On the subject of old motors, does anyone know what the car in Alrewas is? You know, the one on the way to the pub.

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7 minutes ago, frahkn said:

On the subject of old motors, does anyone know what the car in Alrewas is? You know, the one on the way to the pub.

I think it's a 2007 VW Golf in silver...

 

 

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22 minutes ago, tree monkey said:

I might have mentioned before quite how lovely she is but what makes her a special, what was added over the normal none special model?

Thanks, Alan. The Siddeley Special was a model made between about 1934 and 1938. I think they were supposed to show off the companies advanced engineering, or On the car there's no mention of Armstrong, all the badges being Siddeley Special, or S6, so maybe it was because JD Siddeley was retiring, he would have been about 65 when the model launched. Most of the bodywork is aluminium as is the engine block, head and con rods. It's got hydraulic valves, which I think was quite advanced for the time. It was basically the biggest, most expensive model in the line-up at the time costing about as much as a 4 bed house in London. The other models were all known by their RAC HP rating, eg 12HP, 14HP, 16HP and 17HP. The Siddeley Special 5.0 litre engine, was RAC rated at 30HP, which is roughly 110BHP.

About 253 were made but being made of aluminium, quite a few got donated and scrapped for the war effort. Worldwide there's about 22 extant about half of those are roadworthy.

My dad bought this one in 1997 and although he didn't make much progress with it before he died in 2015, he was always dreaming of the day he could drive it. I promised him I'd get it back on the road and have spent the last four years restoring it. At about 1:43 in this video you can see what it looked like six months into the restoration. Maurice Smith, RIP, helped with panel beating the wings and it's been a feature of the club's stand at Stoneleigh and NEC restoration shows for the last few years.

 

 

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2 hours ago, Machpoint005 said:

I think it's a 2007 VW Golf in silver...

 

 

No, that's on the way to the William, I mean the car on the way to the Crown (it's always there).

 

Also it's not silver and it's more like 1937 than 2007.

Edited by frahkn

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37 minutes ago, frahkn said:

No, that's on the way to the William, I mean the car on the way to the Crown (it's always there).

 

Also it's not silver and it's more like 1937 than 2007.

:D

 

Mine was a valid answer to your question as posed, though!

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1 hour ago, Machpoint005 said:

:D

 

Mine was a valid answer to your question as posed, though!

It certainly was.

 

I think mine was a fairly 'open' question but if you've seen the car, you know the one I mean. That's no use to those who haven't seen it but then they can't help me (unless they are very lucky guessers).

 

My wife (who has no interest whatever in cars but has an amazing memory) tells me that the car is green and that she thinks the reg. was  STU 510.

Edited by frahkn

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On 28/11/2019 at 11:40, peterboat said:

I have just installed a bigger bank, so I will follow your sdvice and flog them on and buy super ecofans! The only issue I can think off is massive bow waves from me and the water skiers, so maybe with hydra foils the fans could get me up onto the plane?

I went on a couple of Hydro foils in the early seventies from Copenhagen to Malmo. Amazing bits of kit, no idea if they are still in use today but went like stink.

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Could do with an ecofan. Its 38 degrees at 11.40 pm. I could just stand it on any metal surface and off it would go.

powers out tonight ( load shifting for melbourne) less people to complain in rural areas.

Still mustnt grumble we are not currently on fire and have sold the van so mission accomplished.

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Whenever I read one of these threads I get a little confused by the ''experts'' that regularly pop up to say that eco fans don't work.

They never explain what they actually mean by that. I suspect that what they are saying is that they aren't capable of sending heat from one end of a narrow boat to the other.

This is most likely to be true if a) the boat is poorly insulated ( usually with spray foam which is next to useless ) and b) the stove is sited at the very front of the cabin which is usually the highest point and where the doors are. Heat won't travel down hill!

Our 4 kw stove is sited about as centrally as it is possible to be and heats the entire interior ( except the rear cabin which is entirely separate ) perfectly adequately. The eco fan directs heat enough to be unbearable at times if you are sitting in it's ''line of fire'' at 8 feet from it. We leave the doors open through to the forward cabin and bathroom with the fan blowing towards that direction when the living area gets too warm and that evens things out. The eco fan also ensures that the 'heat bubble' around the stove is dispersed, without this the  adjacent wall would get terrifically hot even though the stove is installed at the correct distances.

 

BTW,  I'm not trying to convince myself because it cost a lot of money Smelly, it did indeed cost a lot of money but when the motor stopped working five years later I replaced it ( the motor) because it does the job it's meant to. 

 

 Keith

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21 minutes ago, Steilsteven said:

Whenever I read one of these threads I get a little confused by the ''experts'' that regularly pop up to say that eco fans don't work.

They never explain what they actually mean by that. I suspect that what they are saying is that they aren't capable of sending heat from one end of a narrow boat to the other.

This is most likely to be true if a) the boat is poorly insulated ( usually with spray foam which is next to useless ) and b) the stove is sited at the very front of the cabin which is usually the highest point and where the doors are. Heat won't travel down hill!

Our 4 kw stove is sited about as centrally as it is possible to be and heats the entire interior ( except the rear cabin which is entirely separate ) perfectly adequately. The eco fan directs heat enough to be unbearable at times if you are sitting in it's ''line of fire'' at 8 feet from it. We leave the doors open through to the forward cabin and bathroom with the fan blowing towards that direction when the living area gets too warm and that evens things out. The eco fan also ensures that the 'heat bubble' around the stove is dispersed, without this the  adjacent wall would get terrifically hot even though the stove is installed at the correct distances.

 

BTW,  I'm not trying to convince myself because it cost a lot of money Smelly, it did indeed cost a lot of money but when the motor stopped working five years later I replaced it ( the motor) because it does the job it's meant to. 

 

 Keith

I knew you were joking when you said spray foam insulation is next to useless ? You ar kidding on the believers that ecofans work arnt you? ?

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I've been thinking about buying an ecofan for my FIL's cabin and, being a skeptic, I googled "ecofan thermodynamics" to see if people have done any kind of analysis before I make a decision. Well, this was the only thread that came up so I find myself in a boating forum even though I don't (yet) have a boat.

 

There's been some interesting discussion on this thread, and a good mix of people for and against using an ecofan. I've thought about the original topic enough to sort of come to an opinion so I thought I would add here to see what you all think.

 

Let's start simple: a wood stove by itself. You burn wood inside - the box and the flue get hot. You feel warm when the heat transfers from the burning stuff to the box itself to the air surrounding the box and then finally to you. There's some radiative heat directly from the box, which hits you and the walls of the room, but we'll ignore that for now since that complicates things a bit.

 

Now add a large heatsink to the firebox. Not an ecofan, just a heatsink the size of an ecofan. What happens? Now there's an additional path for heat transfer from the box to the air surrounding the box. The base of the heatsink creates a "cold" spot on the box, where heat will, excuse the semantics, sink into. This creates a larger heat gradient within the wall of the box. I'm not gonna get into the math, but when you have a larger heat gradient, you have more heat transfer happening. Great, more heat is transferring from the fire to the box. And obviously the heatsink is dissipating heat with its large surface area. So it's like the firebox has a little bit more surface area to release a little bit more heat.

Where would that heat have gone if not for the heatsink? When the box is at steady state (heat from the fire to the box = heat from the box to the air), most of the excess heat would have traveled up the flue.

 

Now turn that heatsink into an ecofan. The heatsink starts to warm up, and a heat gradient forms at the choke point where the thermocouple is. The fan turns on and starts doing two things: 1) establishes a horizontal air current at waist height (where there normally wouldn't be) and 2) increases heat transfer at the heatsink by pulling in ambient air to be heated up. (2) will cool down the heatsink further so now there's a greater heat gradient at the foot of the heatsink and therefore more heat transfer from the box. And (1) is a tricky thing to discuss without doing simulations because it depends on the size/shape of the room how helpful it is. For a stationary person who can sit in front of the fan that'd be nice, but I think it's important to think about performance/output and whole room heating for a given amount of wood. However, we do know that hot air will rise and it will generally stay on the ceiling unless something pushes it around. For a fan-less room that would generally be from more hot air rising up or people moving around. That seems inefficient because the longer that hot air stays up there, the more it's going to leak heat out of your room (or boat). So I think the fan would improve the performance of the stove in that regard.

 

In summary, it seems like the ecofan will increase heat transfer from the firebox to ambient air as well as help mix hot air with ambient air. But the Made in Canada version on Amazon is still $80, so if I was buying for myself I would have to consider whether those benefits translate to a reduction in wood usage and then how many cords of wood would this save per year. Thankfully, I would buy this as a gift so I don't have to think about all that.

 

Back to the original topic of pointing the ecofan the "wrong" way, this is a tricky one. The ecofan is directing heat from the box back onto the flue where it would have been if there was no ecofan, but it's still acting as a fan to mix air / aid in convection. It's possible that the flue being warmer is enhancing the draft which increases burn rate and gives you a warmer room, compared to having an ecofan pointed way from the draft. This is a stretch because I would guess this back-transfer of heat is small compared to the amount of heat already in the flue that is coming directly from the fire. The other possibility is that for this type of room (maybe it's small enough or insulated enough), it's more effective to enhance the convective current than to disrupt it.

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4 minutes ago, storminnorman said:

I've been thinking about buying an ecofan for my FIL's cabin and, being a skeptic, I googled "ecofan thermodynamics" to see if people have done any kind of analysis before I make a decision. Well, this was the only thread that came up so I find myself in a boating forum even though I don't (yet) have a boat.

 

There's been some interesting discussion on this thread, and a good mix of people for and against using an ecofan. I've thought about the original topic enough to sort of come to an opinion so I thought I would add here to see what you all think.

 

Let's start simple: a wood stove by itself. You burn wood inside - the box and the flue get hot. You feel warm when the heat transfers from the burning stuff to the box itself to the air surrounding the box and then finally to you. There's some radiative heat directly from the box, which hits you and the walls of the room, but we'll ignore that for now since that complicates things a bit.

 

Now add a large heatsink to the firebox. Not an ecofan, just a heatsink the size of an ecofan. What happens? Now there's an additional path for heat transfer from the box to the air surrounding the box. The base of the heatsink creates a "cold" spot on the box, where heat will, excuse the semantics, sink into. This creates a larger heat gradient within the wall of the box. I'm not gonna get into the math, but when you have a larger heat gradient, you have more heat transfer happening. Great, more heat is transferring from the fire to the box. And obviously the heatsink is dissipating heat with its large surface area. So it's like the firebox has a little bit more surface area to release a little bit more heat.

Where would that heat have gone if not for the heatsink? When the box is at steady state (heat from the fire to the box = heat from the box to the air), most of the excess heat would have traveled up the flue.

 

Now turn that heatsink into an ecofan. The heatsink starts to warm up, and a heat gradient forms at the choke point where the thermocouple is. The fan turns on and starts doing two things: 1) establishes a horizontal air current at waist height (where there normally wouldn't be) and 2) increases heat transfer at the heatsink by pulling in ambient air to be heated up. (2) will cool down the heatsink further so now there's a greater heat gradient at the foot of the heatsink and therefore more heat transfer from the box. And (1) is a tricky thing to discuss without doing simulations because it depends on the size/shape of the room how helpful it is. For a stationary person who can sit in front of the fan that'd be nice, but I think it's important to think about performance/output and whole room heating for a given amount of wood. However, we do know that hot air will rise and it will generally stay on the ceiling unless something pushes it around. For a fan-less room that would generally be from more hot air rising up or people moving around. That seems inefficient because the longer that hot air stays up there, the more it's going to leak heat out of your room (or boat). So I think the fan would improve the performance of the stove in that regard.

 

In summary, it seems like the ecofan will increase heat transfer from the firebox to ambient air as well as help mix hot air with ambient air. But the Made in Canada version on Amazon is still $80, so if I was buying for myself I would have to consider whether those benefits translate to a reduction in wood usage and then how many cords of wood would this save per year. Thankfully, I would buy this as a gift so I don't have to think about all that.

 

Back to the original topic of pointing the ecofan the "wrong" way, this is a tricky one. The ecofan is directing heat from the box back onto the flue where it would have been if there was no ecofan, but it's still acting as a fan to mix air / aid in convection. It's possible that the flue being warmer is enhancing the draft which increases burn rate and gives you a warmer room, compared to having an ecofan pointed way from the draft. This is a stretch because I would guess this back-transfer of heat is small compared to the amount of heat already in the flue that is coming directly from the fire. The other possibility is that for this type of room (maybe it's small enough or insulated enough), it's more effective to enhance the convective current than to disrupt it.

Bloody hell. That's a hell of a lot of typing. I will condense it for you. 

" They don't work" 

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1 hour ago, storminnorman said:

Well, this was the only thread that came up so I find myself in a boating forum even though I don't (yet) have a boat.

Too much theory.

Not enough fact.

 

The ultimate test on ecofans (other fans are available) is here at

Its all about moving the stagnant air which exists at head height when sitting (ON OUR BOTE) rather than the hot air near the roof and the returning cold air near the floor. Smelly and Peter are living in the distant past.

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11 minutes ago, Dr Bob said:

Too much theory.

Not enough fact.

 

The ultimate test on ecofans (other fans are available) is here at

Its all about moving the stagnant air which exists at head height when sitting (ON OUR BOTE) rather than the hot air near the roof and the returning cold air near the floor. Smelly and Peter are living in the distant past.

Andy. Did you buy the chocolate fireguard with the tin of snake oil I told you about on fleabay 😎

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