one word answer.............. dangerous

I found the installation manual. On page 13 is mentions a sidewall termination using an add-on draft inducer. This needs to be done by someone who knows how to this properly. I doubt you can use a PVC vent. I would think the exhaust gases are too hot.

Here is a link that might be useful: Trane XV80 Installation manual

oh yeah.... here they do it here with the add on draft inducer on the outside of the house but everyone I go to that has that done if its metal the flue pipe is all but rusted out ... if they try to use pvc vent it is cracked and brittle....... don't do it would be my opinion