Spinning cowl

[Bro]

For diesel stove I'd like to improve the flue/ chimney to give more consistent performance, in particular to reduce down draft.

Anyone have experience of Spinning cowls they'd like to share?

[pearley]

We bought one for our coal stove in January after experiencing more down draught problems than before. Its stopped the problem and a great conversation piece as sitting on the sofa you can see it moving through the Houdini. 

[Alan de Enfield]

17 minutes ago, pearley said:

Its stopped the problem and a great conversation piece as sitting on the sofa you can see it moving through the Houdini. 

A very clever chap that Houdini - he could move thru solid walls and escape from water filled tanks, so moving thru a hatch shouldn't be a problem.

[rusty69]

3 minutes ago, Alan de Enfield said:

A very clever chap that Houdini - 

He was very Weisz

[Bro]

1 hour ago, pearley said:

We bought one for our coal stove in January after experiencing more down draught problems than before. Its stopped the problem and a great conversation piece as sitting on the sofa you can see it moving through the Houdini. 

What make of spinner have you?

[pearley]

Bought ours from The Little Chimney Company. He's usually moored around Fazeley. 

[Phil Ambrose]

Or you could get a downdraft diverter also known as an H cowl. I had one on my drip feed heater maybe 15 years ago and it was brilliant, I now have one in the SF fire on my present boat so again no downdraft or fire running away 

Phil 

[system 4-50]

Please, not a stroboscopic silver one!

[Dr Bob]

Now I dont want to de-rail the thread but I have a related question. Over the winter our stove has worked quite well but some days it doesnt seem to draw as well as on other days. I have never really thought about it but maybe it was down to wind direction. Is this a 'downdraft' issue that one of these cowls will solve, or is it just because the flue pipe is too short ie probably 8ft total (we have a shortish chimney on the roof of the nb)? Once I get a bit of heat in the fire, it takes off very well.

[nikvah]

Not sure if the OP means the spinning cowl that has blades that spin like a top or the sort that turn with a wind-vane.

We have a cowl that revolves to show it's back to the wind and it makes a big difference to the draw of our diesel stove. When we're underway I remove it because it adds a foot to the chimney height and then the fire becomes very inefficient and smokey despite our slipstream.

[blackrose]

Whatever cowl you get, check it's suitable for your diesel stove first. Some of the cowls people are recommending will be perfectly fine for solid fuel stoves, but not necessarily for diesel. I know because I once recommended a vedetta cowl to someone on this forum because that's what I've got, but it didn't work on his diesel stove. I had told him to check compatibility first but he didn't do it. 

[Robbo]

 

Now I dont want to de-rail the thread but I have a related question. Over the winter our stove has worked quite well but some days it doesnt seem to draw as well as on other days. I have never really thought about it but maybe it was down to wind direction. Is this a 'downdraft' issue that one of these cowls will solve, or is it just because the flue pipe is too short ie probably 8ft total (we have a shortish chimney on the roof of the nb)? Once I get a bit of heat in the fire, it takes off very well.

It may be due to the barometric pressure?  

[Dr Bob]

Wind I can understand but wouldn't the barometric pressure be the same inside and outside the boat so not make a difference? I know an 8ft long flue is too short for a good draw so I am thinking replace the chinese hat with a cowl (either H or spinning or wotever) to improve it. As per the OP's post, I'd like to hear some more experiences.

[Bro]

 

Wind I can understand but wouldn't the barometric pressure be the same inside and outside the boat so not make a difference? I know an 8ft long flue is too short for a good draw so I am thinking replace the chinese hat with a cowl (either H or spinning or wotever) to improve it. As per the OP's post, I'd like to hear some more experiences.

And specifically, if you will, for diesel stove application.

Thanks to all for contributions.

[koukouvagia]

I have one of these for our Refleks.  The are a little less obtrusive than the "H" variety.  Never had any trouble with wind or the fire not drawing properly.  They are pretty pricey, however.

[koukouvagia]

Refleks also make this exhaust regulator for "problematic ducts".  I've never seen one, so I don't know how well they work.  They might be an alternative solution to a spinning cowl.

Edited March 12, 2018 by koukouvagia

[MtB]

 

For diesel stove I'd like to improve the flue/ chimney to give more consistent performance, in particular to reduce down draft.

Anyone have experience of Spinning cowls they'd like to share?

 

Like Ecofans and Axiom propellers, they rely on the placebo effect to work.

Oh, and magnetic/electronic water conditioners too!

[Dr Bob]

 

 

Like Ecofans and Axiom propellers, they rely on the placebo effect to work.

Oh, and magnetic/electronic water conditioners too!

Oh dear! It's not one of them then? Now my Baby equaliser fan works great .....so I am now confused. My stove/flue work ok but it would be better to ensure a good draw ALL the time. So cowls are not going to work them ......for a stove not a diesel heater?

[Ex Brummie]

I have a Swedish cowl on my Bubble stove. This is similar to a vedette, with a skirt around the opening at the top, that incorporates a lid. This eliminates down draught, and also reduces draught 'suction'. Your stove probably incorporates a draught stabiliser as illustrated by Koukouvagia.

There is alsosome benefit to be had by having an insulated double skinned chimney outside the boat. This maintains a higher temperature in the flue, thus aiding draw.

[Dr Bob]

 

 

There is alsosome benefit to be had by having an insulated double skinned chimney outside the boat. This maintains a higher temperature in the flue, thus aiding draw.

I've got that.

[Mac of Cygnet]

5 hours ago, Dr Bob said:

Oh dear! It's not one of them then? Now my Baby equaliser fan works great .......

Aren't all babies the same anyway?  It's only later that inequalities appear.

[Bro]

19 hours ago, Ex Brummie said:

I have a Swedish cowl on my Bubble stove. This is similar to a vedette, with a skirt around the opening at the top, that incorporates a lid. This eliminates down draught, and also reduces draught 'suction'. Your stove probably incorporates a draught stabiliser as illustrated by Koukouvagia.

There is alsosome benefit to be had by having an insulated double skinned chimney outside the boat. This maintains a higher temperature in the flue, thus aiding draw.

Thanks Brummie.

My stove is Bubble corner oil burner.  Several makers of Swedish cowls, can you recall who supplied yours?

[smileypete]

On 11/3/2018 at 17:33, Dr Bob said:

Now I dont want to de-rail the thread but I have a related question. Over the winter our stove has worked quite well but some days it doesnt seem to draw as well as on other days. I have never really thought about it but maybe it was down to wind direction. Is this a 'downdraft' issue that one of these cowls will solve, or is it just because the flue pipe is too short ie probably 8ft total (we have a shortish chimney on the roof of the nb)? Once I get a bit of heat in the fire, it takes off very well.

Colder flue ie single skin? Also the wind can suck air out of vents and small gaps in the windows.

[Ex Brummie]

7 hours ago, Bro said:

Thanks Brummie.

My stove is Bubble corner oil burner.  Several makers of Swedish cowls, can you recall who supplied yours?

A local heating supplies in Wolverhampton. National suppliers like M.M.F. would have available, but many local merchants should be able to help. Look for one who specialises in woodburners.

[smileypete]

Something else to check is the flue and especially any baffle plate is clean.