I've decided to go geothermal to replace my electric baseboard system. After receiving three quotes, I selected an installer and will be beginning the installation of a GeoStar Sycamore heat pump in the next couple weeks. It's a 2,100 sq ft house in Lansing, NY, 43,000 BTU/h loss, 21,000 BTU/h gain. The installer has proposed a 4 ton system with five 150ft trenches containing 600ft of pipe in each, buried 6ft deep. I'm not sure what size pipe. My question is related to the loop field design. Instead of using five separate 150ft trenches in a grid layout, is there any reason a single 600ft trench with five pipes shouldn't be used?