I'm in the process of having a new system installed in northern New Jersey. I got two quotes from the two biggest Waterfurnace dealers in the area and went with the one that could meet my timeline + more reasonable cost. I'm getting a 4 ton 7 Series, desuperheater, etc. Calculated heating load is around 3.5 ton. Well drilling started on Monday. Originally the main contractor told me I was going to get 2 x 375' x 1 1/4" wells. Drilling has not gone well at all, in 5 days they managed to get one ~300' well and have elected to 'double pipe it.' Essentially they pushed two separate U bends down it (I have four pipe ends above ground) and are claiming it's spacer separated + grouted between. I didn't see it go in the hole so I have no way to verify this. Before I let the crew leave I called my installer and verified that he had signed off on this design change. He swears that he has validated this design and I will still have ample loop but the math side of me is skeptical. If it were this simple it seems to me that every system would be designed this way to cut drilling cost in half. Is this a reasonable design choice? Anybody have the math to say how two vertical loops with normal 10-15' spacing would compare vs this?