Secondary air in a stove burner

[zardoz]

A forum member mentioned this a while back

Secondary air is really good, stoves can be twice as efficient, its just a pipe that sucks air from outside the stove, through a pipe across the red hot embers to heat the air up, and then out above the flames, unburnt gases then burn, brill to watch and doubles the efficiency.

Can someone please explain what is meant by this. I just cant quite picture what is being talked of here ? can someone show me one?

 

[scarecrow]

sounds like another inlet flue to feed fresh warm to the top of the burner

 

[pedrobedro]

Look on google for airwash system, our stove uses it to recirculate hot air back through the stove. It helps to cut smoke and keep the door glass clear of staining. It's not perfect but it does help, you can turn the air down or up with a damper lever to steady the fire down and when burning wood the effect is almost instant.

 

[octo0072000]

airwash

try this gives you an idea and pictures etc

http://www.windysmithy.co.uk/html/woodburners.htm

this is a good site loads of info

http://www.boilerstoves.co.uk/stove-terminology.html

 

[zardoz]

Thanks for the replies. I dont suppose anyone has any diagrams of how a pipe might be routed?

 

[octo0072000]

airwash

picture of air wash are you sure you mean airwash or are you meaning preheating the incoming air


http://www.stovesonline.co.uk/airwash-stove.html

 

[Raf]

Airwash looks different to what the OP is asking about i think.

more pre heating but then dumping the clean heated air above the flames... bit like an after burner type thing????

interested to see some diagrams though....

 

[pedrobedro]

If you read this it sounds exactly the same as airwash.

 

[stormin]

If you read this it sounds exactly the same as airwash.

No, basic Airwash introduces the air via vents just above the door, so it's potentially cold or cool air straight from the room entring the fire. Secondary air is ducted from the rear of the stove, being warmed on it's way before being added at the top of the door, possibly in combination with cool basic airwash air to do the same job.
Primary air tends to come from the base of the fire or underneath the grate. Not really useful for woodburning which tends to burn from the top. Primary air is only really useful when you are just starting a wood fire or have just topped up fuel. It's more useful when burning coal which has a greater liking for air from underneath the fire bed or grate.