Open fire smoking

sillysocks · 28-02-2015 9:22pm #1

We had an extension with open fire built before the summer, and now that we're using the Fire regularly we've noticed that on windy nights gusts of wind are pushing a cloud of smoke into the room every so often.
I think there's just a bird guard on the top of the chimney, is there somethjbg that we can put at the top of the chimney to stop this? I'm fearing for the ceiling and wallpaper getting covered in soot!

jack of all · 28-02-2015 9:27pm

There are a number of reasons why this could be happening, but first you should check if there is sufficient backgrounf ventilation for the fire (is there a wall vent in the room where the fire is located). If the fire is starved of adequate replacement air this can cause such issues, in addition to carbon monoxide risks! If a window is left slightly open in the room does the issue still arise?

sillysocks · 28-02-2015 9:33pm

Yes there is a vent in the room, on the same wall as the chimney breast. Haven't tried leaving the window open a bit. It doesn't happen every night, only nights when it's very windy and you'd almost hear a gust outside and then see the burst of smoke for a second or two. We probably see it more when the fire is starting off and maybe isn't burning strong enough to 'fight off' the wind!

gutteruu · 01-03-2015 2:21pm

Does this new chimney meet all the regs on page 6 (part 2.4) HERE

Is there an apex of another roof nearby?

sillysocks · 01-03-2015 2:40pm

Well it was built by a very reputable builder so I only hope it meets regulations. One thing I should have said is that it's a single story extension so the chimney wouldn't be as long as in a two story house.
It's not really near any other buildings (other than the one side where it's attached to existing house obviously!)

sky6 · 02-03-2015 8:57pm

sillysocks wrote: »

Well it was built by a very reputable builder so I only hope it meets regulations. One thing I should have said is that it's a single story extension so the chimney wouldn't be as long as in a two story house.
It's not really near any other buildings (other than the one side where it's attached to existing house obviously!)

that could well be your problem. You need to raise the Chimney up above the Roof of the House and see if that cures it. When wind and air hit a building it can be deflected back across the top of the Chimney. This creates various pressures on the Chimney. Resulting in the type of problems your experiencing. The hotter a chimney gets the better they work. Raising it maybe the solution as it also increases the draw.

Spocker · 02-03-2015 10:11pm

Raising the chimney might be a bit unsightly, you could try a H-Pot or Chimney Fan : http://www.eurocowls.com/superc.html

sillysocks · 02-03-2015 10:20pm

Thanks to you both. To be honest I don't think it's bad enough to start raising the chimney (and don't have the will to have builders traipsing through again either!!). Since we started using the fire in maybe Sept/Oct it's only happened maybe 5 or 6 nights, when it's very windy.
Do you know if there's much cost involved with buying and installing those cowls? Even ballpark?

That's kind of what I was hoping with my first post, wondering was there even a basic cowl that helped stop breezes coming down even if it didn't fully stop the wind 100%.

Spocker · 02-03-2015 10:31pm

I can't see a Hpot being massively expensive (but I'm not sure); I do know that the fans start at around the €400 mark, and you'd need someone to take off the existing pot to fit the fan, along with the electrics - the variable switch is an extra cost

sky6 · 02-03-2015 11:15pm

The H cowl shouldn't be more than about 150 E. If you know of a sheet metal shop they can make one for you. May work out cheaper.

ART6 · 04-03-2015 5:19pm

sillysocks wrote: »

We had an extension with open fire built before the summer, and now that we're using the Fire regularly we've noticed that on windy nights gusts of wind are pushing a cloud of smoke into the room every so often.
I think there's just a bird guard on the top of the chimney, is there somethjbg that we can put at the top of the chimney to stop this? I'm fearing for the ceiling and wallpaper getting covered in soot!

I had that problem for years (in a 1974-built house), and over the time I had tried all sorts of cowls -- spinners, "tees", ones that were supposed to turn way from the wind but never did. I stumbled across stainless steel "Wind Kat" cowls, made in Germany, and as an engineer their design suggested to me that they should work, but they are horrendously expensive and don't seem to be available in Ireland. I contacted their UK supplier and bought one and now, even in the worst wind conditions, there is no trace whatever of a downdraft. They also have the advantage that they are very easy to fit -- they have a spigot on the base that fits into the chimney pot, so installing one is simply a matter of dropping it in. They have a hinged rain cover that can be swung out of the way for sweeping the chimney from the top down.

I have no connection with this company, so I will not post details of contacts, but I did find them very easy to deal with and very helpful. If you Google "Windkat cowls" you will find their web pages.

Open fire smoking

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