Becton Bunny

[wiccan]

I have a Becton Bunny 4 stove fitted. It has a secondary airflow mechanism above the door which allocate to come in to help keep the glass clean. Anyway, in these high winds I am getting a lot of Backdraft of smoke which pours out of said vent. I have recently swept chimney and check for blockages. I have checked throat plate is sitting properly. All appears to be ok. However I am getting lots of smoke coming from the vent wits no way to stop it.

 

Any ideas or reasonable suggestions to help will be appreciated.

 

Thanks Gary

[bowten]

Depending on where you are could be getting alot of downdraught,I must say I am experiencing the same myself.There are types of chimney hats that help to stop this.At the moment I am not wearing one.

[wiccan]

I have removed my standard chimney hat which seems to have helped reduce the smoke but its still coming in. I have now resorted to putting some exhaust covering behind the vent and pushing the vent back on (this seems to have helped a lot). It does mean I am unable to use the vent - at least I can still control the fire using the Ash Pan drawer.

 

As a side note - the Carbon Monoxide readings event changed - so apart from being a little smoky (which is clearing now) we should be safe.

 

Thank you for your response - it does make me a little happier than this COULD be semi normal in such high winds.

[Nickhlx]

I have removed my standard chimney hat which seems to have helped reduce the smoke but its still coming in. I have now resorted to putting some exhaust covering behind the vent and pushing the vent back on (this seems to have helped a lot). It does mean I am unable to use the vent - at least I can still control the fire using the Ash Pan drawer.

 

As a side note - the Carbon Monoxide readings event changed - so apart from being a little smoky (which is clearing now) we should be safe.

 

Thank you for your response - it does make me a little happier than this COULD be semi normal in such high winds.

 

The issue is that the wind is causing pressure differences that exceed that caused by the column of hot gases within the chimney...

 

So the answer is to increase the pressure within the cabin with respect to that at the top of the chimney.

 

This can be done in many ways...

i) by opening a vent ( window) on the windward side in the cabin / boat - not always practical, especially if its raining

ii) by closing windows on the leeward side of the cabin / boat as the pressure on this side of the boat is reduced

 

or the opposite at the top of the chimney

 

iii) to decrease the pressure at the top of the chimney, one of those swivelling right angled vent things, angled so that the wind hits the back of it

 

Putting some sort of obstruction ( large box ? ) on the windward side of the flue might also work, with some experimentation of position.. Be aware of the fire hazard though !

 

 

Nick

Edited January 30, 2013 by Nickhlx

[wiccan]

Nick. Good suggestions. I will try the window option first. I think I shall invest in one of those rotating chimney cowls. I only have a short chimney on which I suppose doesnt help. I will get a 24 - 28 inch one for when moored.

 

Im not very good when it comes to DIY designing - so the box idea.......I'll give that one a miss :-)

 

Thanks again.