Burning wood that has seasoned down to 18% but has got wet due to rain blowing in on it

[Muddy42]

3 hours ago, GarethM said:

Is the space between the liner and the brickwork filled with vermiculite?.

 

Just thinking it's touching the brickwork and taking all the heat away 

 

It just shows how precious stoves have become that this is a consideration, but yes its a double skinned liner surrounded by some overpriced insulation beads.

 

I dunno a stove should be so simple, but yet there has been this whole industry created to sell extra stuff, services and installation that wasn't required in the past.  One of my Clearviews works fine and doesn't even have a flue liner.  And before you ask, I clean it twice a year and have seen the CCTV footage and its spotless with no creosote. I also have various carbon monoxide testers, yawn.

Edited Tuesday at 14:29 by Muddy42

[GarethM]

It's not really a case of older having the design, it's more brute force approach to flue temperatures of 400c+ Vs less than 200c on newer models.

 

You can't argue with the laws of thermodynamics, that and properties are now sealed tight to prevent draughts so you can't force flow out a chimney without being room sealed versions.

 

If you crack open a window and the fire improves you know it's starved of oxygen.

[Muddy42]

42 minutes ago, GarethM said:

It's not really a case of older having the design, it's more brute force approach to flue temperatures of 400c+ Vs less than 200c on newer models.

 

You can't argue with the laws of thermodynamics, that and properties are now sealed tight to prevent draughts so you can't force flow out a chimney without being room sealed versions.

 

If you crack open a window and the fire improves you know it's starved of oxygen.

 

Agreed. I suspect eco design (with an external independent air supply and perfectly set up flue liner) has been designed for a modern air tight house. Mine certainly isn't air tight and oxygen starvation isn't a problem.

 

[Steven P]

1 hour ago, GarethM said:

It's not really a case of older having the design, it's more brute force approach to flue temperatures of 400c+ Vs less than 200c on newer models.

 

You can't argue with the laws of thermodynamics, that and properties are now sealed tight to prevent draughts so you can't force flow out a chimney without being room sealed versions.

 

If you crack open a window and the fire improves you know it's starved of oxygen.

 

This has been a thing few times here in the last couple of years, stove in a new build or new extension sealed tight has problems, rarely get "My 100 year old house fire doesn't draw very well".

 

Insulated flu... mine is a single skin liner and the chimney brickwork retains a lot of heat - great for upstairs bedroom after a couple of days fires - wonder if an insulated liner retains as much heat?

[GarethM]

It's the usual we want a fireplace here, yet not on a outside wall.

 

Installers do as they're told to a certain degree, instead of opting for a room sealed version that adds costs as Dave down the shop says he'll install one cheaper etc.

 

I can only say from my experience of twin wall, it does retain a bit of heat and isn't cold to the touch. Providing I've not left the bypass open during refilling then I could remove skin.

[Muddy42]

I just think some of the modern stoves are very fussy in terms of their operating conditions - perfectly straight flue liner of the exact length, insulation, cowel, register plate etc. The internal design and baffles may actually reduce draft, to help recirculate and reburn smoke, extracting maximum heat from the wood, maximum efficiency, cooler smoke etc.  I get all that but if anything is slightly not right, you can get smoke in the room or other operating difficulties.

 

Whereas Ive had several older that will work anywhere in any old unlined chimney.  They light instantly and roar like a train within seconds and I've never had issues like with this eco design one.  Yes you use slightly more logs but my firewood is free aside from labour and fuel.  

[Rob_the_Sparky]

21 hours ago, Steven P said:

 

Insulated flu... mine is a single skin liner and the chimney brickwork retains a lot of heat - great for upstairs bedroom after a couple of days fires - wonder if an insulated liner retains as much heat?

Easy answer to that is no.  The thermal mass of the insulated flue is minimal so it takes very little energy to warm it up but equally it gets cold more quickly as well.  Not sure there is a simple better or worse here.