Marcos Buenijo wrote:Looks great. I like the secondary air supply.
...
I agree they look good... but I don't see where they've been tested with a full installation.
The secondary air supply sounds good on paper (it's a clean-burn feature in woodstove design, to counteract the operator's tendency to close down the primary air
feed).
It also works OK in outdoor mockups when working with the J-tube or combustion chamber alone.
But with the load of a full thermal mass system, our
experience has been that any secondary air downstream of the feed tends to produce a 'leaky siphon' effect where the downdraft through the wood is diminished. I have seen a few folks (notably Matt Walker) who've made a secondary air feed work by diminishing the size of the primary feed, and/or by super-cautious handling during the burn. Would love to hear more about how this is working in actual installations.
Possibly you have compensated with some other feature to
boost draft and overcome this effect? Or you're pulling air from within the feed, and re-feeding it, so the opening itself has no change in draft?
When we boosted draft, it tended to make the burn dirtier... your model may be balancing these requirements differently somehow.
We're not going to advocate these until we've had a chance to play with one in person, but I'm excited to see that they're out there. Would love to hear reports from beta testers on performance with full thermal mass in actual buildings.
-Erica