Utilizes a double concentric pipe, the inner one taking away the products of combustion and the outer one bringing the air supply to the stove. This system allows a gas stove to be installed where no flue exists, and because the flue needs very little vertical height to operate, it is often possible to route the flue through the wall in the room to the outside.
Overview
A high level vertical flue termination is made up of a basic vertical kit with extension pieces and accessories to suit the site conditions.
A balanced flue may be terminated either vertically or horizontally. To enable this a basic flue kit is available to which as many additional parts may be added as necessary to achieve an exit conforming to statutory building regulations. A range of accessories including additional lengths and elbows are added to enable build configurations over a range of distances and directions.
Technical Guide for Balanced Flue Systems for Gas Stoves Includes Location of Outlets, Aspect Ratios, Balanced Flue Kits and Positions of Flue Terminals 
