I found a light grey plastic venting on a furnace today manufactured by Hart and Cooley. I checked their web page but found no info on this type of plastic vent. The house and furnace were 1993. The furnace was not condensing type and the plastic flue vented out the side wall. The pipe was approximately 200 degrees. The pipe had specs that said it was ok to 450 deg. but needed 8" clearance. I am flagging the install because of the clearances and the poor installation. All the joints were silicon caulked. Anyone have any experience with this type of venting? I know there is a need for repair of the vent but just wanted to learn more about this product for future reference.