Replace wood burner with open fire

[reg091]

Lots of advice on doing the opposite, but nothing on what I want to do! Moving to house that has wood burner, I want to rip it out and restore open fire.

Questions:

1. Can I leave the liner/flu in place - will an open fire work with a chimney flu/liner?
2. If so is the liner likely to be attached to the chimney or will it fall down into the hearth once I remove the log burner?
3. If so could I fit some kind of metal flange plate to it at the bottom end and attach/fire cement it to the bottom end of the chimney?

Any advice/thoughts welcomed!

 

[bernardgreen]

Can I leave the liner/flu in place - will an open fire work with a chimney flu/liner?

Almost certainly the answer is NO

For an open fire the flue operates at a much lower temperature than the flue of a wood burner. Hence there is less draw to move the combustion products up the flu. Hence the flue for an open fire needs to be designed for low velocity, large cross section and low turbulance.

http://www.rumford.com/articleWhat.html

 

[reg091]

Almost certainly the answer is NO

For an open fire the flue operates at a much lower temperature than the flue of a wood burner. Hence there is less draw to move the combustion products up the flu. Hence the flue for an open fire needs to be designed for low velocity, large cross section and low turbulance.

http://www.rumford.com/articleWhat.html

Thanks, makes sense.

Now, how difficult is it going to be to get the flu out? (How long's a piece of string, I know) I am guessing that they are fixed in some way to the chimney, and possibly "back-filled" (if that is the right expression - I mean the gap between the outside of the flu and the inside of the chimney is filled) perhaps?

 

[reg091]

I think I have answered my own questions on removing the flu - it will be fixed at the top and bottom, and may have vermiculite insulation poured in around it from the top.

Yukky, sounds like a job for a pro...

 

[bernardgreen]

The flue for my log burner is flexible and only fixed at the top beneath the chimney pot and effectively hangs from there.

The open fire in the house we built had a Rumford throat tapered into a flue of 8 inch ceramic liners. I still have the plans and drawings somewhere in the archives. If you decide to go ahead I can probably dig them out for you.

If you have Vermiculite then it will be a nessy job.

 

[scbk]

The first question is why??

 

[foxhole]

The first question is why??

Agree, seems a backward step.?

 

[reg091]

I have no idea what you mean: backwards? A woodburner, in my experience, puts out minimal heat, gets a horribly discoloured glass door, and crucially, makes no crackling sounds!

I put them in the same bracket as gel fires, fake coal gas fires etc: a false pretense of a real fire. What is the point in pretending to have a real fire when you can have one!

 

[bernardgreen]

Wood burners can put out a lot of heat and are reasonably efficient. But as you say an open fire, which may not be as efficient as a log burner, is much more cosy and homely

 

[reg091]

Each to their own of course but, for me, the interaction with an open fire is part of the enjoymentoking, turning the logs, selecting just the right log to go on... simple pleasures!

 

[bernardgreen]

Toasting forks for bread and marsh mallow

 

[foxhole]

My wood burner chucks out over 13kw , doubt you could achieve anything like that with open fire, virtually smoke free , not something open fires can do burning wood.No danger of sparks setting the house on fire , glass stays clean if used correctly.

 

[scbk]

An open fire is (apparently) 20% efficient, modern stoves are 80-90% - an open fire gives off very little heat to the room, most of it goes up the chimney. And even when the fire isn't lit, you're still losing heat from the house.

You still need to poke logs with a stove!

? A woodburner, in my experience, puts out minimal heat, gets a horribly discoloured glass door, and crucially, makes no crackling sounds!

In that case there must either be something wrong with the stove/chimney, or it is being using incorrectly ie vents shut too much

Crackling sounds vary by wood species.

 

[reg091]

OP here resurrecting this thread as I have now moved to the house and can have a good look at the chimney.

The previous owners took the wood burner with them so I can see straight up inside the chimney: a couple of meters up the square chimney has a "plate" with a round flue hole. As this is so far up the chimney I don't think this could be a retro-installed liner but is the original flue build. (?)

Also, there is no gather, damper, smoke shelf, it is just a straight vertical shaft from hearth to sky.

The house was built in 1970 and has a capped-off gas point next to the hearth. Consequently I am thinking that this chimney was built for a gas fire and is not going to be suitable for a solid fuel open fire.

Any advice welcome!

 

[foxhole]

Move again