I have the open-loop Geo thermal system, and yes that is exactly what it is. Unfortunately, in the winter months, it has to run constantly because of both how slow it heats, and how cold Michigan winters is. The house was built with hot water radiator heat, with currently I use LP on those cold months. I use to use a wood boiler but that broke down, and I put in the open-loop for more the air conditioning than heating. I pulled the wood boiler, but was thinking to put another wood heat source for backup heat. This time I am thinking of outside to keep down on the dust, and lower the insurance by $150 a year. RMH don't look to be a good fit with the constant wood feeding of the J tubes, and the fact that RHM generally heat gravel or cob rather than water. I know the gasifier boilers are more efficient that the normal wood boilers, (which uses 10x more wood than an RHM) and a lot more efficient that the outside wood boiliers. so I am asking what people think would be a good option for secondary wood heat.
