Insulating air inlet pipe for Wood burner?

[Andehh]

My wood burner needs a 50mm ( i think it was) pipe to suck in air from outside the house. I am keen to insulate this just so that when we are not using the wood burner it isnt just sat there cold & behind plasterboard.

 

Does anyone know of any pipe insulation that can be safely installed in the vicinity of an insulated flu? Obviously full belt & braces on safety/proximity to a fireplace.

 

Many thanks,

[JohnMo]

50mm sounds small.

 

My pipe going into the stove is aluminium.  You can wrap in rockwool if you want.  Rockwool doesn't burn

[jamieled]

You can probably just use any standard insulation. The air inlet pipe will likely be nowhere near the flue once it exits the plasterboard. There's no heat anywhere near the air inlet pipe on ours.

[saveasteading]

Interesting point made recently was the air flow through the intake and up the flue, when the fire isn't lit. It will take room heat from the stove.

So I am thinking we need a seasonal  external cap on the intake.

 

On a positive, a stove can provide stack ventilation in the summer for quick air changes (flue door open).

 

I agree that insulating the intake pipe is a good idea, but you can simply stuff the void with leftover mineral wool. 

[Andehh]

Thanks very much all! 

[dpmiller]

20 hours ago, saveasteading said:

So I am thinking we need a seasonal  external cap on the intake.

 

will the stove's air controls not close off airflow? On ours, both levers close their respective vents completely.

[saveasteading]

1 hour ago, dpmiller said:

will the stove's air controls not close off airflow? On ours, both levers close their respective vents completely.

I don't think we can shut off the external air completely. That would be a good feature though. I will enquire.

[saveasteading]

The site team think there is not a total shutoff of air available. We will find out later.

[ProDave]

On 13/02/2023 at 10:07, saveasteading said:

Interesting point made recently was the air flow through the intake and up the flue, when the fire isn't lit. It will take room heat from the stove.

So I am thinking we need a seasonal  external cap on the intake.

 

On a positive, a stove can provide stack ventilation in the summer for quick air changes (flue door open).

 

I agree that insulating the intake pipe is a good idea, but you can simply stuff the void with leftover mineral wool. 

Urban myth I think.

 

I have just checked with the Ir thermometer, and no part of the stove or the single wall flue exiting the top, is any colder than any other part of the room, so any natural draught and heat loss through the stove is tiny.

 

My intake duct is insulated as it passes through the wall then down under the floor.  It does not get hot there, I used plastic ducting once it enters the wall and down.

[ProDave]

2 hours ago, saveasteading said:

I don't think we can shut off the external air completely. That would be a good feature though. I will enquire.

Modern stoves have a limit on how far you can shut down the intake to meet modern limits.  Some have a little crafty footnote that you can remove the stop if you really really want to close it down further.

[saveasteading]

1 hour ago, ProDave said:

no part of the stove or the single wall flue exiting the top, is any colder than any other part of the room

If air is going up the flue from outside, at say 5'C and the room is at 20'C then there must be a slow and steady heat transfer, and loss. Perhaps not significant though, esp with an insulated flue, heat shield behind, ceramics inside. 

 

Not worth a knitted flue cosy. Perhaps not worth worrying about at all.

Another perceived problem resolved by the BH think tank.

[ProDave]

It's on a par with the toilet cisterns refilling with 4C water and just sitting there being warmed up by heat from the house.

[Alan Ambrose]

>>> Not worth a knitted flue cosy.

 

I think that something striped and crocheted would be lovely.