A faster draft in the heat riser might lead to unburned smoke being pulled through too quickly, and incomplete combustion. It's better than a big woodstove chimney, but still iffy.
Karl Meisenbach wrote:Hi all,
Can somebody please clarify for me then how big the burn tunnel's diameter needs to be?
People recommend Ianto's book which states that it needs to be smaller than both the feed's and the heat riser's diameter, but Ernie mentions that it should be the same.
Which one is it because currently my RMH mock up has a burn tunnel with a smaller diameter and the draw is inconsistent..if i make it the same all the way through will that solve the problem?
Another issue raised by Jeremy is the notion of having a larger diameter for the heat riser. Can the heat riser's diameter be larger than both the feed tube and the burn tunnel?
Would the ideal diametrical setup look like this:
burn tunnel<feed tube<heat riser
or maybe this:
burn tunnel=feed tube<heat riser
burn tunnel=feed tube=heat riser
Thank you for your insight...