A thought on heating a greenhouse

[Ross]

In northern areas (lots of the board members live in cold climates) folks shun from greenhouses because of heating costs in winter. I have really been wanting a greenhouse for intermediate orchids for years, but can't justify the cost. A thought I have been mulling over, though, is why not install one of those exterior wood burning furnaces many folks use? They take large logs, use hot water heat and pump the hot water to the house (or, in this case, the greenhouse - or both). As long as one has a supply of wood (common to us Northerners ) to burn, I think it might be a suitable alternative to fossil fuels or electric. Any thoughts out there?