Just thought I'd add my experience with this unit we installed this past fall. We really wanted to go with a gasifier, but water storage and cost held us back. We live in an old house with a very small basement, so I ended up building an addition to house the boiler. I'm not completely satisfied with my wood consumption so far. I've put a damper in the flue to slow down the burn rate, and we've experimented with the aquastat circulation temps and the auto damper temps. This boiler has a 135 gallon jacket and our house has cast radiators, but I'd love to add more water storage in the future. We looked into the collapsable tanks for gasifiers, but they seemed to be pretty pricey. I've heard of people who use propane tanks and insulate them. And then I've heard some talk about pressurized water storage being more efficient than non-pressurized. Still learning the basics.