does anyone have any experience with using outdoor wood-fired furnaces as primary/supplimental heat for greenhouses?
i haven't used wood heat for my green houses. Unless you are planning on making a "hot house" then you don't need a lot of heat. If you make a hot house and plan on vigerous growing during the short days of winter then supplimental lighting becomes necessary. Plants are stimulated by the number of hours a day that they get light. temperature is only part of the equation. The biggest problem I have had is getting rid of heat on the cold but sunny days in the winter. a good greenhouse can quickly get hot enought to kill plants in the winter if the heat isn't removed.