Glenn Herbert wrote:If you want a batch box, yes. If you want a J-tube, you will have reduced performance due to the shorter heat riser. This could be mitigated by a very good chimney, or by recessing the floor so the J-tube can sit below floor level.
Ah - I missed the 6" part of your question. A 6" J-tube may work well enough fitting in a 90cm overall height.