I'm in the planning stages of our new home. We are thinking to build an ICF on a slab on grade. I know in order to use the Geo unit to heat my water it needs to be near the water heater. Is it important for this to be near the center of the home to make to rooms heat and cool evenly? My initial design had the unit on an outside wall in a utility room. The home is 64 x 48, will that create a problem cooling rooms on the opposite corner? I have been told by some that it needs to be in the center while others have said that with new variable speed fans it really won't matter. What do you all say? Thanks in advance.

If the home is built well and the ducts are designed and built correctly it shouldn't matter.
If you hire the lowest bidder to install the duct system it also won't matter because the temps will be uneven regardless of unit placement.

That said a small disparity in temperatures is expected.

Thank you kind sir. I am definitely checking out any and all installers for quality of work and will talk to a few references before deciding on my installer. I appreciate your input, it helps a lot.