Using an Ecofan the wrong way?

[blackrose]

Firstly, apologies if this has been posted before, but it's new to me.

 

I was on a neighbour's boat today and noticed he had his Ecofan pointing the wrong way around - towards the flue.

 

When I asked him why he said that when his teenage son was on the boat he'd been burning joss sticks and he'd noticed strong natural air convection currents running from the floor towards the stove, going up parallel to the flue and bulkhead behind the flue, and then across the ceiling. He said if you use an Ecofan the normal way you're fighting against natural convection and it's better to assist the natural warm air currents with the Ecofan rather than working against them. He said his boat feels much warmer since he turned the fan the "wrong" way around.

 

I'd never thought about it before but it makes sense and I thought it was interesting. Or is this old news to seasoned Ecofan (or other stove top fan) users?

 

 

 

 

Edited November 25, 2019 by blackrose

[Sea Dog]

Do you hear there:  @mrsmelly report to the Living Afloat Department at the rush.

 

 

[David Mack]

I thought you were going to suggest blowing the fan round to generate heat!

[cuthound]

And there was me thinking that by using the Ecofan the wrong way that Dr Bob had found a way to force cool his overworked lithium battery charging alternator. ?

[Dr Bob]

16 minutes ago, cuthound said:

And there was me thinking that by using the Ecofan the wrong way that Dr Bob had found a way to force cool his overworked lithium battery charging alternator. ?

Nah, the fans at the front and the alternator are at the back! The ecofan fell off the alternator when I tried it.?

[Dr Bob]

10 hours ago, blackrose said:

Firstly, apologies if this has been posted before, but it's new to me.

 

I was on a neighbour's boat today and noticed he had his Ecofan pointing the wrong way around - towards the flue.

 

When I asked him why he said that when his teenage son was on the boat he'd been burning joss sticks and he'd noticed strong natural air convection currents running from the floor towards the stove, going up parallel to the flue and bulkhead behind the flue, and then across the ceiling. He said if you use an Ecofan the normal way you're fighting against natural convection and it's better to assist the natural warm air currents with the Ecofan rather than working against them. He said his boat feels much warmer since he turned the fan the "wrong" way around.

 

I'd never thought about it before but it makes sense and I thought it was interesting. Or is this old news to seasoned Ecofan (or other stove top fan) users?

 

 

 

 

I'd not heard that one before!

It is interesting. On our bote, the low level flow to the stove is coming in at floor level not top of stove level so with the fan in normal direction you are creating a separate airflow out from the stove at face level (when sitting down). It may be different on a fat boat. Reversing the fan should increase the main circulation as you say.

One other benefit could be a faster fan speed. If it is pulling colder air in then there should be a bigger temp differential over the pleltier cell so more voltage??? 

My stove is black though. Not blue.

[Guest]

Which only goes to show they are a waste of money!

Popcorn anybody?

[Dr Bob]

1 minute ago, peterboat said:

Which only goes to show they are a waste of money!

Popcorn anybody?

I agree. I can't see why anyone would buy a blue stove.

[Hudds Lad]

2 minutes ago, Dr Bob said:

I agree. I can't see why anyone would buy a blue stove.

its blue with cold because its outside in the snow as per picture, as it has no door it cannot be lit so will stay blue despite someone trying to warm it by pinging rubber arrows off it

[Dr Bob]

2 minutes ago, Hudds Lad said:

its blue with cold because its outside in the snow as per picture, as it has no door it cannot be lit so will stay blue despite someone trying to warm it by pinging rubber arrows off it

If it's blue with cold it's no bl**dy wonder the fans not working.

[Guest]

6 minutes ago, Dr Bob said:

I agree. I can't see why anyone would buy a blue stove.

Oy have a baby blue Rayburn cooker though not stove, but it burns coal so maybe is a stove?

[Dr Bob]

1 minute ago, peterboat said:

Oy have a baby blue Rayburn cooker

So it won't be voting for Compo then?

[nicknorman]

Funnily enough I saw this on a friend’s boat for the first time last week. I guess it has been doing the rounds on social media.

 

My take is that yes this natural circulation does exist, however it results in layers of hot air at the top and cold at the bottom. Air is pretty good at flowing in layers and not mixing well. By having the eco fan as you suggest, you just reinforce that. By having the eco fan the “normal” way round you disrupt the laminar flow and help to mix up the air, which is a good thing!

[doratheexplorer]

9 minutes ago, nicknorman said:

Funnily enough I saw this on a friend’s boat for the first time last week. I guess it has been doing the rounds on social media.

 

My take is that yes this natural circulation does exist, however it results in layers of hot air at the top and cold at the bottom. Air is pretty good at flowing in layers and not mixing well. By having the eco fan as you suggest, you just reinforce that. By having the eco fan the “normal” way round you disrupt the laminar flow and help to mix up the air, which is a good thing!

I definately get this problem with much colder air around my feet.  I wonder if a slow moving battery powered ceiling fan would help?

[frahkn]

6 minutes ago, doratheexplorer said:

I definately get this problem with much colder air around my feet.  I wonder if a slow moving battery powered ceiling fan would help?

My Ecofan is useless at moving heat through the boat. I use it because it is good at moving heat (close to the stove) from the ceiling to the floor. Without it I sit with freezing feet but nearly boil my head when I stand up.

[doratheexplorer]

3 minutes ago, frahkn said:

My Ecofan is useless at moving heat through the boat. I use it because it is good at moving heat (close to the stove) from the ceiling to the floor. Without it I sit with freezing feet but nearly boil my head when I stand up.

I had an ecofan.  It didn't do anything.  So I bought slippers instead.

[mrsmelly]

12 hours ago, Sea Dog said:

Do you hear there:  @mrsmelly report to the Living Afloat Department at the rush.

 

 

Thanks for bringing this to my attention indeed. This is a very very dangerous thing to do. The fan must ALWAYS be pointing into the largest clear area of space, this is imperative for safety reasons. It would be safe if the stove was centraly located away from any bulkheads but in  a normal boat instalation with the stove in a corner near to hull sides and cabin sides etc, the blast of furnace temperature air being emitted by the eco fan being directed against any wood will cause instant incineration. Large areas of wood would be scorched with seconds and be a blaze within one minute. Any ceramic tiles would crack and fall away and any firetardent board used as backing would warp and curl up at the edges exposing bare wood to instantly incinerate. I think we must again inform the uninitiated that the heat generated by such fans has been measured and found to be similar to that produced by a 747 jet engine at 3 inches.

Edited November 26, 2019 by mrsmelly

[frahkn]

1 hour ago, doratheexplorer said:

I had an ecofan.  It didn't do anything.  So I bought slippers instead.

 

I have managed the first 66 years without buying slippers so now I don't really feel like breaking my duck. Even if you disagree, I hope to find support amongst duck lovers generally!

[matty40s]

With global warming, the ecofan helps the plants grow in a cold spring

[mrsmelly]

6 minutes ago, matty40s said:

With global warming, the ecofan helps the plants grow in a cold spring

I see that strong beer was involved lol.

[blackrose]

2 hours ago, nicknorman said:

Funnily enough I saw this on a friend’s boat for the first time last week. I guess it has been doing the rounds on social media.

 

My take is that yes this natural circulation does exist, however it results in layers of hot air at the top and cold at the bottom. Air is pretty good at flowing in layers and not mixing well. By having the eco fan as you suggest, you just reinforce that. By having the eco fan the “normal” way round you disrupt the laminar flow and help to mix up the air, which is a good thing!

 

I'm not sure. What my simplified drawing doesn't show is the warm air at the ceiling of the boat falling as it gradually cools and then returns back to the stove. Heat convection is a circular movement and if the natural convection currents are assisted and increased then the whole boat should warm up quicker. Anyway, my neighbour seems to think it works much better the wrong way around.

[Alan de Enfield]

20 minutes ago, blackrose said:

Anyway, my neighbour seems to think it works much better the wrong way around.

And, some deluded folk actually believe an Ecofan (other brands available) works

[ditchcrawler]

One day I WILL buy one of these, but not sure if I would risk taking it to the boat.

[cuthound]

2 hours ago, matty40s said:

With global warming, the ecofan helps the plants grow in a cold spring

 

If Ecofans work that well on a wooden table, just imagine how well they work when placed on a hot stove! ?

[Sea Dog]

2 hours ago, frahkn said:

 

I have managed the first 66 years without buying slippers so now I don't really feel like breaking my duck.

Are you waiting until you're ready for one of those big ones you put both feet in?