I have a 2400 sqft. 'Calf-Contemporary' (lots of glass but, 8' ceilings, finished basement) in the New Haven CT area (existing oil-fired, FHA). Not sure what the heat load is (just moved in) but, the seemingly properly sized A/C system is a current 2.5 ton system. At 150' vertical bore per ton, will 375' to 450' do the trick for heating/cooling/hot water? I'm trying to learn as much as possible before engaging a contractor (not easy to find in this area, so far). Any info will be greatly appreciated!
I think you may need a little bit more, but you need to find out how much heat you need and what your heat gain is as well. Then design a system. You can buy HVAC calc here for a 1 time fee. In the blue bar on top.