Twin Wall Chimney Flue
What is a twin wall chimney flue?
So, no chimney in the room where you want your stove? Why not create one? It’s easy – clip-together parts from top to bottom.
Twin wall flue is also known as DW (double wall) or HT (High Temperature) flue and is a clip-together chimney twin wall system enabling wood burning stoves to be added almost anywhere in a property. No adhesives or sealing potions at joints – slide one part into another and add a narrow locking band.
Twin wall flue pipe cannot be cut to length by you to make it fit (although there are adjustable lengths) and one therefore needs to plan carefully when installing a twin wall flue chimney.
Twin wall flue pipe can be used to safely take the combustion gases from a wood burning stove and outside to the atmosphere.
Twin wall flue pipe for the chimney: an introduction
External twin wall flue pipeTwin wall flue pipe is a metal tube (flue) insulated with approx. an inch of insulation (two layers of stainless steel with insulation between). The insulation is necessary to keep the gases hot. Were you to use non-insulated vitreous pipe for the whole of your chimney, then the gases would likely cool too much and start to slow rather than rise with this causing the smoke underneath to “dam”. This might cause the smoke below to exit out of the vents in your stove instead of the top of your chimney.
Cooling gases also form condensation which forms on the inner walls of the flue and runs down into the stove (mixed with soot it is a disgusting brown liquid).
So keeping gases hot is good.