Hi Thomas, Need to do more research and will get a hold of the handbook. Have it on my list of to-do's. In Central portugal it gets quite cold during the winter for several months and we have a lot of humidity. I am looking to heat one area of 80m" and another of 120m2, mainly living areas. Yes there is an existing chimney n one but as we are redoing the roof chimney can be remodelled as necessary. In a second home there is a ruin and everything to be redone. I do have some background on RMH and do know there is a team that is starting out here building very simple models and a more experienced builder in the south of the country but his rates are too high for me to afford. I know Peter Berg's Batch site and will look into the J tube. Thanks for the help and the welcome. Ivan
