Help with Sizing/ Cost of Geothermal System
I've never posted here but started reading posts on geothermal systems and got pretty confused! I'm hoping someone can help at least figure out what questions we need to be asking. My husband and I are planning a build of a 2-story, 3200 sq foot home in Delaware on 2 acres (flat land). We have received bids from 3 builders so far and they have given us the following specs and prices for the geothermal (all closed-loop)
Builder 1 - 5 ton, trench installation, $22k
Builder 2 - 7 ton, well installation, $39k
Builder 3 - 5 ton, well installation, $32k
Builder 2 says that even if we ended up needing just over 3 ton on 1st floor and just over 2 ton on second, they will round up, with would be how we got to 7.
My questions - should they be rounding up or could an oversized system be detrimental? How can we figure out which size we should be going with?
Is there a big cost savings between the well vs trench?
Basically, any insight would be wonderful so that we can go back and ask the right questions.
Thanks in advance for any help!