To suggest that the requirements of North Minn are the norm for open loop geo everywhere is ridiculous. (Once again employing the obscure to disprove the norm.)

Looby: when you suggest the engineers of the equipment are "dummies" do not forget they speak in minimum requirements. Not everyone has the same requirements. Some clims. are cooling dominated etc.
We noted before that efficiencies rise with more gpm, but what if we have an artesian well that delivers 1.5-2 gpm/ton with no pump cost? Would it still be more efficient to pump the water to a higher gpm? What if old well can't deliver more than 1.5 gpm/ton, would we still advise drilling a new well to "save money".
Manufacturers' tend to speak in terms of minimum system requirements and leave design to the installers from there. 10 or 20gpm/ton may raise COP but that doesn't make it necessary or good design.
I've yet to have a system that requires more than recommended (in mid MI).
j