I am planning out a new install for a Drolet Austral III and need to reduce the clearance with either double wall pipe, or wall heat shields. Which method is generally preferred? It seems to me, using double wall pipe indoors would be a waste of radiant heat from the exhaust.
Austral III manual: https://sbiweb.blob.core.windows.net/media/5710/46142a_23-04-2020.pdf
Austral III manual: https://sbiweb.blob.core.windows.net/media/5710/46142a_23-04-2020.pdf