At first I thought an OWB would be the way to go...easier install, mess is outside and near wood pile and initial start up cost is less or maybe equal. Then I read up a bit and see in the long run an interior gassifier will save me money and labor...not to mention fewer trips outside for wood / loading the boiler and no underground lines to run saving me $$(but I guess a storage system will use up that $$ savings?). Ideally I would keep my oil boiler as a back up but now the Mrs. is very concerned about having a wood boiler with "flames" in the same proximity(apprx. 12' away) as the oil boiler and I have a concern about being able to use the same existing chimney for the wood boiler and the oil boiler. Are these 2 valid concerns? Maybe I should go OWB?