Peter van den Berg wrote:Matthew, I think I know the answer. My mini J-tube is producing a smell now and then what I could describe as "not smoke but definitely cause by heat". It's coming out of the grain ends of the fuel and it is caused by heated up (boiling) moist in the wood itself. When you smell the same odor again, feel the grain ends. When those are really hot you've found the cause of that weird smell.
The moist is turning to steam, thereby expanding to 1500 times and blowing out of the grain ends. The air is sucked in the feed at the same time so there's a stream of air which is taking the water vapor with it. That's the reason why you can't smell it a yard away and is only there when the heater is running really hot. In my case, the odor is strongest when burning soft fuel like poplar and willow.
i really think you locked it down. once again peter your
experience in the field of fire amazes me. this makes a s ton of sense. i figured the whole time if i was loosing draft and getting some kickback smells the fire would then run a at lesser temperature. although i have been getting hotter and hotter temps as time goes it seems. especially when it really cold out, this thing roars.
with what you are saying, my grasp of the concepts were apparently spot on the whole time. didn't think that the wood "steam" out the ends like that. so this hits the nail on the head for my understanding of the situation. really appreciate it.
-Thanks!!!