Our new heating system was installed in the spring of 2010. It is powered by the next generation of outdoor wood boilers. It gasifies the wood, resulting in reduced emissions when at its operating temperature. Hot water is moved underground in insulated piping and then put through a Modine heat exchanger. We were able to heat our greenhouses using 8 cords of locally cut wood, and replaced between 800 to 1000 gallons of propane. Our plans for 2011 include adding under bench heating in the plant house and soil heating in the tomato house.
You can read a report here.
We are grateful for the support we received both in engineering help and cost share assistance that allowed us to make this system possible.