How to Make a Secondary Combustion Manifold

How to Make a Secondary Combustion Manifold

Written by: Senna Scott

Last month Dan did some surgery on Norm’s reclaimed woodstove he got from his in-laws beach cabin, giving it a secondary combustion manifold using outside air.

The idea is to make it burn the gasses released by the wood that conventional stoves waste.

Dan says, “We put in an air supply line piped from the outside to feed the fire so the fire isn’t pulling the warm air from the house’s envelope which helps retain warmth.”

“That air supply then feeds into a manifold overtop of the fire. Dozens of little holes were drilled into a steel tubing manifold I built to spread air out through the stove. A smaller air supply splits off from the manifold at the bottom of the stove, runs across the bottom and to the front of the stove to assist with convection and combustion. Norm will then lines the walls of the stove with firebricks.”

What’s the point of doing all this??

So this fire could burn hotter and more efficiently! 🔥

Norm reports back post-retrofit saying that “the wood stove system is working perfectly! It probably cleans the smoke up to maybe 50 percent, and burns the gasses out of the emissions as well as increasing efficiency of the burn within the burn chamber – increasing the efficiency from about 80 percent to 95 percent!”

( SO cool! )

Norm continued to say, “You can tell it is a clean burn because the glass stays clean and you have a really cool fire. The actual flame in the stove comes not just from the bottom, but it shoots down from the top – making it a really cool flame from both directions, but it’s not overly hot!”

📸 Thanks Norm & Dan for sharing your “sustainability” weekend adventures and photos of your project! 😀