Coaxial vent system of a pipe inside a pipe (generally 4 7) the inside pipe is for exhaust while the outer pipe brings in outside air for combustion. The design of these stoves allows for a completely sealed system that does not compromise the inside air quality of your home. It also lets you vent a product horizontally (great for when an appliance is installed on an outside wall). Direct vent appliances are usually limited to a length of 40ft (with a maximum horizontal length of 20ft) that will allow an appliance to function properly.BTU: 21,000 Depth: 17-7 16 Glass Viewing Size: 29-3 4W x 18-9 16 Glass Window: Tempered Height: 33-1 2 Ignition Type: IPI Venting Size: 4 7 Venting Type: Zero Clearance Direct Vent Width: 36
