Gas chimney liners by Napoleon are designed for venting gas appliances like water heaters, furnaces, boilers, and fireplaces. The flexible aluminum liners come in long lengths and uncoil without kinking to install in a single piece that eliminates the need for junctions. Complete kits include all the necessary parts, including the roof termination and the cap that protects the chimney from the elements. Several lengths and a variety of diameters are available to fit your Napoleon appliance.
I am seeing flexible chimney liner installation videos on the internet. They have an insulation sleeve. The dealer where I am shopping for a wood stove says I do not need insulation around the chimney liner. Won't the flue cool down too rapidly if it's not insulated?
By Collin C. - NFI Master Hearth Professional on November 8, 2013
Use of insulation is recommended in all liner installation for maximum performance of the stove, however there is one scenario when it is not needed. If your chimney is located on an inside wall and nearly all of the chimney passes through the interior of the building envelope, you can get away without insulation.