I live in Michigan and the heat output of ground source heat pumps is inadequate if I size the units for AC. I am considering the 2 stage WaterFurnace Envision series heat pumps. I plan on adding a modulating condensing boiler for other purposes and think that it would be ideal for a supplemental heat source for the ground source heat pump by adding a hydro coil to the air handler. I would be interested in hearing opinions on adding a hydro coil as a supplemental heat source to this heat pump and how to set up the controls. Also, I assume it is not a good idea to oversize the heat pump for cooling to get greater heat output because it will lead to short cycling and inadequate humidity removal but I would like confirmation of that.