Thank you, TXCraig1, as always. it is so nice to know such device. in the meantime, when I searched around this afternoon my time,I found some people uses air mover to control the emission very efficiently. I can understand this as the smoke are the emission which not sufficiently burnt, given enough of oxygen in the combustion, the smoke problem could be remove, all the emission from burnt wood will be only the hydration. I will try the air mover first as it is readily available in China market. if not successful, I will contact the non smoke device manufacturer. thank you again, TXCraig1, you are very helpful .