Hi fellow experts, New here. My house is built in late 1960s. 1600 sq ft of finished space plus about 700 sq ft of unfinished basement. Current AC and gas heat is about 12-13 years old, not quite dead yet but am considering replacing with geo thermal due to the 30% tax credit. Talked to 3 contractors but only 2 got back to me. Contractor 1: 3 ton system, 480 ft loop length. Water furnace 5 series. Contractor 2: 3 ton system, 600 ft loop length. Water furnace 7 series plus water heater. Obviously both proposal have different price due to the hardware difference. My main question is, how would the 2 system with different loop lengths affect the final performance? I read that general rule is 150-200ft per ton. If that is true, is seems like both proposals range from high end of 600ft for 3 ton to low end of 480ft per 3 ton. Giving all things equal, what would the extra loop length buy me? Thanks.
A correction to the initial post. Contractor 2 was actually quoting for a 4 ton system. 600 ft makes more sense now.
