I have a forced air oil furnace and a hot water oil burner venting into same chimney. I need a chimney solution for a gasifier, sooo which makes the most sense? Both long term sense and cost? 1. replace oil furnace with electric furnace for back up. Replace oil hot water heater with electric water heater. Now I gain a chimney to vent the gasifier which also will heat the hot water. 2. Direct vent oil furnace and go with electric hot water heater to gain chimney for gasifier? I have windows everywhere and wonder if direct venting oil furnace can be an issue even though it will be for back up once gasifier is in place? 3. Direct vent gasifier and deal with the visible stainless steel pipe outside the house that could have been hidden inside the chimney if I free up the flue? looking for best solution long term and cost wise?