Now that temps are running in the high twenties to low thirties at night my OAK to my Englander 10-CPM is condensing - enough so there are puddles of water underneath. I found some related threads here with a solution of insulating it, but someone also said that insulating was a bad idea on the chance that the OAK could become the exhaust under certain conditions. I don't think pre-heating the air would be a possibility. Just curious if anyone else has had the issue and what they did to remedy it.