Wind noise in chimney

wishbone

I am the proud owner of a newly installed WS Aoife Stove. It's great, it has been very nicely installed and I love it - there's just one thing...the noise in the chimney. This noise did not exist when we had the open fireplace.

On Friday the lads removed and opened up the fireplace, put in new lintels, the scamolex boards etc and then came back on Monday to fit the stove/flue liner etc. Over the weekend it sounded like motorbikes were going by the house, presumably from the wind whistling down the chimney. I was hopeful come Monday when the flue liner and chimney hat were fitted that this noise would go away and certainly the buzzing sound has stopped but there is significant wind noise.

the exact components I have are:

FL/125/5 Clamp Collar for 125mm Flexi
FL/125/7 Chimney Hat for 125mm diameter flexi
FL/125/8 Flue Joiner for 125mm diameter flexi TK/0309/09
FL/SF/125/10-316 9 Meter Pack Flexi Flue for Solid Fuel

Is the problem the chimney hat? I've heard there are H shaped chimney hats - would they be better?

I believe it's downdraught but am not 100% sure.

thanks
Wishbone.

North West

Hi Wishbone
Did they put insulation in between flexible flue and flues were already there ?. If not that could be causing some of the noise.
NW

wishbone

Hi North West

Thanks for your reply
Is vermiculite insulation? I think so, if so there was 300 litres of it used.
Apparently we had a 9.5 inch chimney flue.
Wishbone

fredgalway

Hi wishbone You may have a leak between flexi and stove pipe. Why did you use 125mm flexi, should be 150mm minimun

wishbone

fredgalway wrote: »

Hi wishbone You may have a leak between flexi and stove pipe. Why did you use 125mm flexi, should be 150mm minimun

Not sure. Will get them to check when they replace the skamolex boards which we foolishly painted with the wrong paint and now need to be replaced as the paint smokes! GRRRR.

Thanks for your reply.
Wishbone

wishbone

Hi all,

I'm still looking for advice.
The stove crowd have changed the cowl twice, once with an anti-downdraught cowl and now with an H shaped cowl. Despite this there is still wind coming down the chimney. When I light the stove initially on a windy day which is every day these days, with briquettes the stove fills with smoke and I need to open the door slightly to get it going, by opening the door the smoke goes up the chimney easier it would seem. The noise of the wind is quite loud. On non-windy days the stove if perfect. The noise is coming specifically it would seem from the top of the door, near the airwash vent. I checked that there is no gap with paper and also I presume if there was a gap the briquette smoke would be coming into the room but there isn't even a sniff of briquette with the door closed.

I rang the stove company and they suggested I contacted Mi-flue I believe they're called and they suggested putting a vent in the room. The room itself does not have one as we built an extension onto it, but it's not a sealed room as the extension has a vent. She said there was no way to prove a vent would work beforehand...even with opening all doors/windows...which has no impact.

Any other thoughts?
Thanks.
Wishbone

DGOBS

Opening a window would prove a vent!

wishbone

DGOBS wrote: »

Opening a window would prove a vent!

Thanks so based on opening the windows and doors having no impact would that mean that there's no point in getting one and therefore the problem is something else?

DGOBS

All open flues appliances should have a fixed vent to supply combustion air to it, but in answer, if you cracked open a window in the room and it didm't resolve the issue, then no, a vent is only providing air same as the window

North West

Hi Wishbone
What height is your chimney above ridge board. Are there any obstructions around house like tall trees or buildings. Something like these could cause a type of down draught as the wind blows from a certain position. post photo of chimney outside and any building trees or obsticles etc.
NW

shane0007

North West wrote: »

Hi Wishbone
What height is your chimney above ridge board. Are there any obstructions around house like tall trees or buildings. Something like these could cause a type of down draught as the wind blows from a certain position. post photo of chimney outside and any building trees or obsticles etc.
NW

I would be looking also along this line. Make sure the flue terminal/termination point is outside the negative pressure zone surrounding your roof.

wishbone

There is a tall tree at the end of the garden, about 10 metres away I would guess. You can see the chimney in the attached pic - I would say the tree at the end of the garden is about the same height as the chimney. If it is higher, does it mean the chimney has to be extended? Is there no cowl that can get over this pressure issue?

Thanks again for all your comments.

Wearb

Chase that crow away and see if it makes any difference

wishbone

Wearb wrote: »

Chase that crow away and see if it makes any difference

Opportunistic crow!

shane0007

Was a smoke test carried out on the flue & checked outside to ensure the smoke is only omitted from that flue?

wishbone

shane0007 wrote: »

Was a smoke test carried out on the flue & checked outside to ensure the smoke is only omitted from that flue?

I don't know for sure.
I can do that I expect, do you wonder if it's coming out another chimney pot?

shane0007

wishbone wrote: »

I don't know for sure.
I can do that I expect, do you wonder if it's coming out another chimney pot?

4 flues together could well have deterioration into eachother.
A Flue Flow Test would be a must anyhow & as part of that test, the terminals would be checked for only one omitting smoke.
Just a thought.....

rayfitzharris

wishbone wrote: »

I don't know for sure.
I can do that I expect, do you wonder if it's coming out another chimney pot?

Hi wishbone, didn't you say when you open the stove door a little that the smoke flies up the chimney fine?

Have you the air vent(s) open a bit on the stove? It sounds like if it can get some air from the room it should work ok.

Btw this won't cure wind noise but should improve the smoking up or "draw" problem. I often hear some wind noise when the fire is not lighting but shutting up the vents and air wash can help that too.

wishbone

Just to provide an update. They have come back and have done the smoke test etc. They swapped in another stove to see if that had any impact, it didn't so they put back in my original. So it wasn't the stove., and then replaced the cowl again this time with an anti updraught (rather than downdraught) cowl and the result is that the constant wind noise is gone, there's a bit alright but it is muffled and can really now only be heard on very windy days. In addition even when very windy it is not half as loud as before.
Anyway just thought I'd let you know how things went....
Wishbone

Wearb

Did they replace the cowl and stove at the same time, if so then you don't know which was causing the problem. Or did replacing one help and then the other helped some more?

wishbone

Hi Wearb

They swapped in another stove to see if that had any impact, it didn't so they put back in my original. So it wasn't the stove.

Wearb

wishbone wrote: »

Hi Wearb

They swapped in another stove to see if that had any impact, it didn't so they put back in my original. So it wasn't the stove.

Thanks. Very important to mention that. Otherwise readers of this thread might be misinformed.

sayn

Hi, I know it is a very old post, but I have the same problem after the installation of Vitae 9kw built-in stove. Do you know that is the model of the anti-updraught cowl that has solved your issue? Thank you.

sayn

I am googling anti-updraught cowl, but all I get is about anti-downdraught cowl