Stainless metallic vent liners for non-condensing models can boost furnace charges while clay-covered chimneys are dangerous or out
http://www.mediafire.com/file/w7hj3e9m2t9ulez/pdf-46063-38031.pdf
Stainless steel vent liners for non-condensing gadgets can raise furnace prices when clay-covered chimneys are unsafe or out of code.