Your tank selection should suit you just fine IF you don't mind loading twice/day and sometimes three when it's very cold. I built two boilers 4 years ago using 24 inch for burn chamber (.375 ductile iron well pipe) 4 feet long with baffle 4 inches from rear and 4.5 inches off bottom. The boiler was 36 inch (.250 well pipe) and 5 feet long. The doors are 24 inches and are water cooled. We wish now that we would have made them gasifiers. I've since bought a used gasifier(in Junuary) and found out first hand how much less wood they actually burn. There are so many variables involved when doing a project like this, such as house sq. ft., windows(single or double), ceiling height, insulation, distance from house, type of insulated pipe used, etc. . Using the diameter pipe you have and making it a gasifier should be about a perfect size for the average house. Do yourself a favor and make sure and buy the very best underground pipe you can find. I'm not a big CB fan, but I think they carry about the best insulated pipe on the market, but it isn't cheap. I think I paid about $13/ft. four years ago. I am on my way to start my next new project(a gasifier twice the size of my Empyre) right now. Wife is not real happy about that. Good luck and keep us posted.