So, My dad wasn't worried about the efficiency or the comfort of 2-stage etc. His concern is that he wants the furnace in the basement and the builder doesn't want to do it. He says the basement will be too cold (which someone here said it will be colder). He is concerned with frozen pipes and I guess the coldness of the space in general. Frozen pipes might be a very small chance, but once he knows of a potential problem he doesn't take chances. He wouldn't buy the house they saw that had two sump pumps...... I explained to mom that the hvac contractor has probably engineered (or whatever it's called) the model with the unit in the attic and moving it would involve changing more than just the location of the unit. I suggested that maybe they can run a duct down into the basement for a couple of vents or maybe look into a gas fireplace down there that they could run when there is a vicious cold snap or he is doing stuff down there. Maybe they make a wall heater of some type that would be effective and would be less $ than an actual gas fireplace as they don't plan to finish the space. Not sure if a few vents or a separate heater, or getting them to actually move the furnace would be cheaper and/or most effective. They are extending their attorney review period until they get this sorted out, so it's a big deal to dad. If we can come up with a solution the builder will do that doesn't break the bank it would be great! Thanks for everyone's input.

5 companies are going to give you 5 different answers. all will either accept ductwork as is, or find problems with it. each company will feel as if their solution is the most valid one. same with equipment. you have to sift thru...and make a choice. and stick to the choice instead of switching main stream to another scenerio. "I asked if it would be single speed and he said it would be something in between variable and single - but " it would be educational to know exactly what is between single speed & variable speed?? two speed? wth? in your posts, you've been given good information. I understand it is difficult to impliment this information into your build thru the gc & hvac contractor. but you pay for it...and then you live with it. you lack of knowledge of hvac is what is hanging you up. each company can tell you pretty much whatever they feel like..and you don't really know better. unless its been discussed here. and itrw...online advice isn't really powerful with the mindset of trades people. and if you don't apply the information...what is the use of asking for it? what you could do....if you chose to make a stand... is to hire an indpendent..load calc, duct sizing & layout. inspection of what you have...what can be kept...what needs to be changed..and what it needs to be changed to. then get bids for specifically what has been inspected, designed & sized. and to have this indenpendent third party to verify as install is ongoing & once completed. its a commitment...that truly... I don't think you'll invest in. but it is the right thing to do if you want to get the system right. you pay someone for thier expertiese...then you pay for whatever has been done..whatever modifications are done. and tradespeople talk..every company in your area knows what is going on. so you'll pay well for re-do. in your other thread you've lowrated luxaire on & on as cheap builder's grade equipment. EVERY brand has builder's grade equipment. people get too hung up on name brands. every brand has a lesser advertised brand. it is the combination of equipment for efficiency and the install of the equipment & design sizing & install of ducts that makes or breaks an install. you can put a mismatched greenspeed or xi20 in on a crap duct distribution system..and you'll pay top dollar for crap. poor performance, no comfort but you'll have a pretty name tag to feel good about. people need to plan for hvac & not let it be an afterthought...esp in hot humid climates. my luxaire 15 seer heat pump with variable speed air handler keeps RH to 52-55% ALL the time. I've used my whole house dehumidifier very seldom...and can lower RH as low as I want it. but because I planned on dehumidification prior to spending a penny...I got my RH needs addressed by the efficiency of the a/c & the vs ahu. of course it helps that I save 25% every month by putting my R-8 mastic seald ducts inside the conditioned space & not in the 130 degree vented attic. I went into the install of my system with everything planned & designed with the end game in mind. understand that you can buy an a/c unit...that can come with several different tags to be put on it. because...guess what..most are the same componets on the insde. so what brand do you want to call it today? and what if you get someone to agree to whatever it is that you decide you need? you going to pay for what the first contractor did? he didn't donate his time & materials to you. how does that work out in your mind? re-read your threads...pay attention to what you have been told repeatedly. pay indpendent..get someone what actually has a clue...or get ready to pay for what you have for a long time.and understand that contractor number one...the one you didn't pay attention to untill too late that did a lot of work already...he gets paid too. good luck...you'll need it.

Well, I met with a 3rd HVAC pro yesterday.....and I am now more confused. The manual J calculation that he performed is vastly different from pro #1. Pro #3 suggests a 2-ton unit for basement, and 2 3-ton plus a 4-ton unit for the main level (12 tons total, compare to 7 tons total from pro #1) The load values vary so much between the 2 manual J reports, yet both professionals used the same software. How is the consumer supposed to sort through this information? Pro #3 accounts for infiltration values and duct loads that were much higher than Pro #1. Suggestions on where I go from here? Is there a simple way for me to understand the Manual J report, so that I will know which pro may have calculated incorrectly?

An electronic filter cabinet is the best option for filters and it appears the aprilaire 5000 electronic filter cabinet is the best of the best. http://docs.electronicaircleaners.com/aprilaire_5000_comparision.pdf Here is the trane brochure. Main difference is SEER rating. You are looking at (up to) 16 SEER, 17 SEER, and 18 SEER. The more you pay, the higher the SEER. Just how it goes. https://www.trane.com/content/dam/Trane/residential/downloads/brochure/airconditioners/72-1208-25_HR.pdf The air handler/furnace of all those quotes has a variable speed ECM motor. This makes sense considering anything over 14 SEER needs a VS ECM blower to actually achieve the higher efficiency. http://gemaire.com/american-standard-tem6a0b30h21sa-silver-series-30-000-btu-variable-speed-multi-position-air-handler-208-230-1-60-tem6a0b30h21sa