Hi guys. I am new to the forum. I am in the process of building a new home. It is coming time to make a final decision on my geothermal unit and I need a little help. I live in Tennessee. My home will be 3100 sf with all the living space on one floor with basement garage. House faces to the south. Design heating load 49,872 btu. Design cooling load 35,816 btu. My 1st decision is 4 ton or 5 ton. I have gotten 4 quotes. Only one has recommended 4 ton, the rest were all 5 ton. I am leaning 5 ton for that reason, my builder is also recommending 5 ton, would rather have more than enough than to build and find I don't have enough. Unless someone can convince me otherwise. More than likely going to do cellulose bib insulation on the walls with blown in in attic space. The other choice I have is WaterFurnace series 5 or series 7? $4500 difference in the two with the 5 ton. One company gave me an estimated breakdown of my estimated heating and air expense. There was only $11 difference a month between the two. I know series 7 is more efficient but if they are correct on the utility expense difference, it takes a long long time to make up the $4500 when it is $11 at a time? So it is hard to see spending the extra money for a series 7. Any thoughts or advice? Thanks in advance.