Relative cost of heating fuels

[Thedreamer]

We have a ducted air intake for our woodburner. A flexible metal duct through the hearth to a plastic pipe that goes under our suspended timber floor, works very well.

 

 

 

 

 

 

 

 

 

 

[gdal]

A man hears what he wants to hear

And disregards the rest

[saveasteading]

1 hour ago, Gus Potter said:

drop the duct so you get some insulation over the top of it

A good idea, thanks. 

Trickier to install, but only the once.

 

I suppose the opposite argument is that we would be pre-warming the air for better combustion (I am only guessing that helps in any way).

 

1 hour ago, Gus Potter said:

I may connect the duct to the stove intake

That sounds sensible, as you take control of the draught. The air adjustment on the fire will control the intake. With your current arrangement there will be  a draught into the room when a door is opened.

 

I had originally thought of having a duct to the back of the fire then letting the air find its way,   and some adjustment to the louvre in times of not needing the fire. But I see that most modern fires seem to have a facility for connection so will probably go that way, as drawn  Unfortunately these stoves are double the cost of the excellent Spanish one I was eyeing ( I mean half the price if bought in Spain.....it must be very expensive on the ferry.

[saveasteading]

1 hour ago, Marvin said:

no difference on the noise front.

Very substantial rubber bearings.  

I hope there was more work done after this picture, as there are holes around the copper pipes that need sealing.

 

Pray tell, what is the brick doing?

[Nickfromwales]

8 hours ago, gdal said:

A man hears what he wants to hear

And disregards the rest

Sorry, what did you say?

Something about man......wants....rest? OK, I'm off back to bed  

[Nickfromwales]

9 hours ago, Thedreamer said:

We have a ducted air intake for our woodburner. A flexible metal duct through the hearth to a plastic pipe that goes under our suspended timber floor, works very well.

OK. Another for the ducted air under the suspended floor. I take it the regs require a continuous pipe / air duct from outside the foundation / house perimeter? So, are you not allowed to just drop a dip pipe under a cold-ventilated block and beam foundation?

@saveasteading ? @ProDave ?

Edited March 22, 2022 by Nickfromwales

[dpmiller]

System chimney is another option- I went down that route as it takes wind direction out of the equation.

[Nickfromwales]

1 minute ago, dpmiller said:

System chimney is another option- I went down that route as it takes wind direction out of the equation.

Thanks. Is that a coaxial / split chimney pipe? Does in increase diameter much? What kW appliance and what size flue pipe did you end up with?

[dpmiller]

22 minutes ago, Nickfromwales said:

Thanks. Is that a coaxial / split chimney pipe? Does in increase diameter much? What kW appliance and what size flue pipe did you end up with?

 Schiedel Swift Air, it's a block-based system that can either be a self-supporting stack or you can integrate it into brick/ block

 

https://www.schiedel.com/uk/products/ceramic-system-chimneys/swift-air/

[dpmiller]

[Nickfromwales]

8 minutes ago, dpmiller said:

 Schiedel Swift Air, it's a block-based system that can either be a self-supporting stack or you can integrate it into brick/ block

 

https://www.schiedel.com/uk/products/ceramic-system-chimneys/swift-air/

Can you not do dog-legs with this system. The one I'm reviewing for a client needs 2x change of direction to get away from the PV array on the ( nigh-on whole of the ) rear roof elevation.

[dpmiller]

2 minutes ago, Nickfromwales said:

Can you not do dog-legs with this system. The one I'm reviewing for a client needs 2x change of direction to get away from the PV array on the ( nigh-on whole of the ) rear roof elevation.

Don't believe so. You can do a sideways offset and that's about it.

[Nickfromwales]

6 minutes ago, dpmiller said:

Don't believe so. You can do a sideways offset and that's about it.

Back to under-slung it is then  

54 minutes ago, Nickfromwales said:

So, are you not allowed to just drop a dip pipe under a cold-ventilated block and beam foundation?

@saveasteading ? @ProDave ?

Lets discuss!!

[dpmiller]

Anything useful here Nick?

 

https://www.islandpelletstoves.co.uk/balanced-flue-for-wood-stoves/

[ProDave]

1 hour ago, Nickfromwales said:

So, are you not allowed to just drop a dip pipe under a cold-ventilated block and beam foundation?

When I did our first build 19 years ago, I specifically checked with BC could the duct just come from under the ventilated timber floor and they said yes.  that one just came to a floor vent behind the stove cast into the hearth.

 

This time I didn't bother asking the question, I just did it.  BC noted the ducted air into the stove bud did not ask where exactly it connected to.

[joe90]

1 hour ago, Nickfromwales said:

So, are you not allowed to just drop a dip pipe under a cold-ventilated block and beam foundation?

Why the hell not, I would have done this if I had a vented floor void with block and beam. I could understand a timber floor (risk of fire). Mine is vented to an outside wall under an insulated slab.

[Nickfromwales]

31 minutes ago, joe90 said:

Why the hell not, I would have done this if I had a vented floor void with block and beam. I could understand a timber floor (risk of fire). Mine is vented to an outside wall under an insulated slab.

Looking at specifying BeamShield EPS ( which replaces the breeze blocks ) so a discernible risk of rapid fire spread if anything got 'under'. As it's a clients build, I have to be belt n  braces on diligence.

I wonder if terminating into an up-turned fire box would be an OK solution, eg so the air is sucked up like a hoover and anything ejected would sit under it. Maybe over-thinking this, so perhaps just a piece of duct 1200mm long would be more than suffice as anything problematic would just sit in the 'rest' bend.

[joe90]

22 minutes ago, Nickfromwales said:

Looking at specifying BeamShield EPS ( which replaces the breeze blocks )

Ha, that’s different then, had not come across this before, yes EPS is flammable (Grenfell!) so yes I would duct to outside.

[Nickfromwales]

8 minutes ago, joe90 said:

Ha, that’s different then, had not come across this before, yes EPS is flammable (Grenfell!) so yes I would duct to outside.

Probably would have helped if I mentioned that sooner  My thoughts too. Outside it is then.

[joe90]

3 minutes ago, Nickfromwales said:

Outside it is then.

👍 make sure you put a grill on it, I got a mouse in my woodstove last winter 😱

[Nickfromwales]

Just now, joe90 said:

👍 make sure you put a grill on it, I got a mouse in my woodstove last winter 😱

Nice, with some peppercorn sauce?

 

Noted. Checking / clearing of that grille needs to be added to bi-annual maintenance schedule for client then I suppose!!

[saveasteading]

4 hours ago, Nickfromwales said:

just drop a dip pipe under a cold-ventilated block and beam foundation

Combine all the above nuggets, add my own,  and we have:

Yes it is sensible but make sure the floor is non-combustible, that there is a grille on the underside (with allowance for the air blockage of the grillage) that it can be inspected in case of dust/spiders blocking the intake, and that the air bricks, or other details allow plenty of air at all times.

 

There is more risk of this going wrong in the long term, with change of ownership and lack of maintenance / understanding of air-movement.

[Nickfromwales]

1 hour ago, saveasteading said:

There is more risk of this going wrong in the long term, with change of ownership and lack of maintenance / understanding of air-movement.

That is very important, and I think has "sealed the deal" for me. Continuous ( robust ) pipe / duct to outside is deffo the way forward.

Thanks @all ! 

[Thedreamer]

5 hours ago, Nickfromwales said:

OK. Another for the ducted air under the suspended floor. I take it the regs require a continuous pipe / air duct from outside the foundation / house perimeter? So, are you not allowed to just drop a dip pipe under a cold-ventilated block and beam foundation?

@saveasteading ? @ProDave ?

 

The stove blockwork is the small square in the middle. The pipe just ends at that point under that section of the timber floor. I have heavy concrete blocks that surround my stove hence the reason for it's own foundation. All I can say is that the approach works well for our home, another winter done and electricity heating bill is less than a fiver. 

 

My floor has PIR insulation (this would be flammable!) but then a layer of glasswool and chipboard less flamable. I guess in the event of fire I would have smoke coming out of my airbricks. 🙂

 

[Nickfromwales]

1 minute ago, Thedreamer said:

 

The stove blockwork is the small square in the middle. The pipe just ends at that point under that section of the timber floor. I have heavy concrete blocks that surround my stove hence the reason for it's own foundation. All I can say is that the approach works well for our home, another winter done and electricity heating bill is less than a fiver. 

 

My floor has PIR insulation (this would be flammable!) but then a layer of glasswool and chipboard less flamable. I guess in the event of fire I would have smoke coming out of my airbricks. 🙂

 

Block & beam atop those piers?