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!

Many Thanks!