Best chimney cowl for diesel stove?

[Bro]

Apologies for raising a topic that has possibly been often covered before but my forum search didn't help too much in relation to diesel fuelled stoves specifically.

My Bubble diesel fuelled corner stove is a basic bit of kit with no sophisticated air /fuel mixture control to compensate for short flue or windy conditions.  Currently it has typical boat flue/ chimney with a vane type cowl atop and it works reasonably well at high temperature settings but not so well at low settings.  Snag is my boat is small and rarely has need of the high temp. settings.

The main problem is of course the short flue/ chimney length and that gives problem of maintaining correct air/fuel ratio in anything other than a dead flat wind.

There is talk of 'H' type cowl, vedette cowl, Rotor cowl, etc., etc. so many options but which is best suited for my application? 

Shall be grateful for comments.

[luggsy]

We have a H cowl for very windy days / nights works well 

[Bro]

Thanks Luggsy.  And that's for a diesel fuelled stove?

[koukouvagia]

I've used both these type of flue cap on Refleks stoves. They work perfectly in all conditions. I'm no fan of the H type because I think they are rather intrusive.

Are you certain that your high and low fire settings are correct?

I note that Refleks makes a damper pipe to improve exhaust ventilation.  I've never used one, so I can't recommend one personally.  Like all Refleks parts they are eye-wateringly expensive, especially now the pound is at such a low level.

[luggsy]

5 hours ago, Bro said:

Thanks Luggsy.  And that's for a diesel fuelled stove?

Yes lockgate reflex 

[Ex Brummie]

My Bubble runs quite happily with a 4" S/Steel flue pipe inside a normal boat chimney. This 'double skinning' helps the draught as it keeps the flue warm for its whole length. Attached to the top of the S/Steel pipe is a Swedish cowl, which has a skirt around the cap on the top. This eliminates down-draught in all but the strongest wind. Y our bubble incorporates a draught stabiliser as shown in K K's lower picture. The Swedish cowl looks very similar to the rearmost example in his first picture.

[charleec]

i just thought i'd mention that i have one of the cowls in koukouvagia's picture for sale, the one on the left, my boat came with it without the heater.

[koukouvagia]

14 minutes ago, charleec said:

i just thought i'd mention that i have one of the cowls in koukouvagia's picture for sale, the one on the left, my boat came with it without the heater.

Yes please!  PM sent.

[Bro]

19 hours ago, Ex Brummie said:

My Bubble runs quite happily with a 4" S/Steel flue pipe inside a normal boat chimney. This 'double skinning' helps the draught as it keeps the flue warm for its whole length. Attached to the top of the S/Steel pipe is a Swedish cowl, which has a skirt around the cap on the top. This eliminates down-draught in all but the strongest wind. Y our bubble incorporates a draught stabiliser as shown in K K's lower picture. The Swedish cowl looks very similar to the rearmost example in his first picture.

Thanks Brummie.  My chimney is double skinned but for sure it doesn't have KK's draught stabiliser (wish it did).

I can find several designs for "Swedish" cowls (some even feature a divergent-convergent cone body).  Does the one you use have side slots in the body (same as KK's pic's)?

19 hours ago, charleec said:

i just thought i'd mention that i have one of the cowls in koukouvagia's picture for sale, the one on the left, my boat came with it without the heater.

Looks like KK beat me to it!

[Ex Brummie]

No slots in the skirt. Only the top and bottom are open.