Open Fire.....

[Ian]

Hello News Group. I have not been here before. I have a question about open fires.

I have opened the fire in our lounge (moved in June 2005). It should be suitable for an open fire. I bought a grate, lit the fire, house full of smoke!

The chimney is clear, smoke does come out, but lots also comes out into the front room. How can I improve the draw for my open fire? It is relatively new (2000) extension. The pot is a vented one, for a gas fire, which I have removed. It is now just a top hat.

HELP!

now that I have found this group, I will check out the posts and see if I can help anyone else.

Thanks

Ian

[TonyB]

You need good ventilation so the fire can draw air in. Check your airbricks are not blocked. This may well happen if you have full double glazing which effectively seals the house.

I guess you can test this theory by lighting the fire then opening an outside door or window in another room. If the fire then draws correctly it's a ventilation problem.

The other time this can occur is in windless conditions when there's no airflow over the top of the chimney.

Finally, you say it's a gas fire chimney, it may be too narrow to permit a good enough flow of air/smoke up the chimney for an open fire.

Good luck TonyB

[Stewart]

Are there any high buildings or trees near the chimney? They can affect it.

[LJ.]

[G Cadman]

It's driving me mad trying to remember what this effect is called. I know they use the same method inside car exhausts to get rid of the water in the bottom of silencers. It's some thing like the 'peeto' effect? Answer on a postcard, put me out of my misery.

G.

[DavidM]

When I opened up the fireplace in my 1900 house some years ago I had the same problem. I resolved it by building (bricks, mortar and angle iron!) a throat or constriction (not sure what the corrrect technical name is) at the bottom of the chimney and just above the fireplace. The theory is that as the hot smoke and gasses rise up through this throat they then expand just the other side of it hence creating a low pressure area which then sucks (or draws) the smoke up. We get a little smoke when first starting the fire, but it then very quickly gets sucked out. As already stated, the room needs adequate ventilation so that the fire can drawer properly. It worked for me - hope this helps. David

[Andrew Gabriel]

Are you thinking of Venturi effect across the top of a chimney (which some pot designs accentuate even more) to help draw air up the flue?

That one doesn't ring a bell with me, sorry.

[G Cadman]

Maybe the tube inside an exhaust is called a peeto tube?

[Derryck Croker]

Pitot tube? Dunno what it has to do with chimneys or exhausts though as it's a device to measure pressure.

[Lorenzo]

Yeah, try holding a newspaper across fire opening (like my Dad used to do and scare us to death!) until a decent amount of smoke has gone up chimney. Once you get the flow going it might be better.

Otherwise, I think it is a bit of a dark art getting a chimney to work"