Let me give you my non-professional opinion.

To make any sense of the proposal, the builder (architect, etc.) should complete a comprehensive heat gain/loss calculation (manual J).

To follow up on that, complete model numbers of inside and outside equipment are necessary to see how it blends with the manual j. No mention of indoor coil.

Depending on your layout, you might have problems adequately serving (air flow) all 3600 SF (no mention of zoning?). You could have uncomfortable areas in both heating and cooling trying to accomplish air distribution with a single system.

And depending on the heating BTUs of the HP, the 3 stage furnace might be overkill, especially being propane fueled.

Also, when building a house, it's customary to have a water heater, bathroom fans, range, etc. w/associated wiring and piping included in the price of the house--strange. Were these specifically excluded?

V

Great units, for certain. Is this for one unit or two?

Have you considered the possibility of insulating your hot water pipes and putting in ONE large hot water heater? This would reduce your standby loss (depending on your run length of your pipes). How about a tankless hot water heater? They use way less gas and they are so much easier to install now rather than later.

If this is a two story home, you want to make absolutely certain of the following:

You need either:
(1) a zoned system with two different units.
(2) one system with automatically controlled zones. (Carrier Infinity is known to be among the best with their zoned system and the price would be slightly less than for two systems--IF you do it now rather than later--drywall labor etc).

Don't let anyone tell you that one unit can heat and cool a two story home. It needs to be zoned: either with one unit and thermostatically controlled dampers or two units. Don't take my word for it. Talk to any 2 story homeowner that has one unit for two floors.

Too, I would seriously consider adding HVAC to the basement (especially if you ever plan on finishing the basement) Running the ductwork would only be a matter of a thousand bucks or two. Doing it now is a whole lot less expensive than later. Generally, the air conditioning and heating needs of a basement aren't all that significant and you can often use the same size unit depending on the outdoor exposure of your walls and windows/insulation etc.

Another thing you may want to consider is having your ducts SEALED with a company that specializes in this. It is not uncommon to have brand new ductwork that LEAKS 20% of your system capacity. It is virtually impossible to get your ducts good and tight without this method. Aeroseal is a proven method which blows little particles into the "holes" and permanently seals them from the inside. Typical cost for this size home: perhaps $500-$750. They print the before and after results for you right then and there. It only takes an hour or two.

Cold winters are no problem IF these unit(s) are correctly installed according to the heat load/heat loss of your home. On a twenty thousand dollar job, the HVAC contractor can take an hour or two and run a load for you. Insist on it.

Before you go with American Standard/Trane (which are excellent units), check out the Carrier Infinity system with zoning. (You can have up to EIGHT individually controlled zones) Many professionals and homeowners testify that the Infinity system is the best. I should know as I have two of them!

Good luck!

Thank you both. I have a bunch to think about it seems.

OK, working from novacarrierdude's post...
Carrier 58MVC120-F-20 120k btu 3 stage furnace
Carrier 25HNA66A003 5 ton 16 seer HP
Infinity zone system
size manual D duct to all areas of house including basement
zoning to 4 areas 1 upstair, 2 middle, and 1 basement
everything else is the same

$18912

What do you think?

Don't let anyone tell you that one unit can heat and cool a two story home. It needs to be zoned: either with one unit and thermostatically controlled dampers or two units. Don't take my word for it. Talk to any 2 story homeowner that has one unit for two floors.

OK, here I am. I have a two story home. It has a single unit, a heat pump. We do not have a zoning system. It works fine.

My wife used to have a three story house with a single unit. It wasn't zoned, either. It also worked fine. In these cases, you just have to adjust the manual dampers to balance the house twice a year when you change from heating to cooling and vice versa.

It takes all of a minute or two and is a whole lot cheaper and less complicated that a zoning system.

All good advice. Double check the warranty on the American Standard equipment. When registered, should be 10 years.

You can also check Bryant Evolution system It's the twin brother of Carrier Infinity. If you do zoning I would recommend an Authorized Dealer ~ Carrier or Bryant

Thank you all for the pointers.

Smitjere, where in Idaho are you-- northern panhandle, Boise southwest, Twin Falls south or Idaho Falls/Pocatello east? All a little different climate-wise.

speedymonk...sounds like a fellow Idahoan. I live in Rockland...closer to Pocatello.

I am in VA with a 4500sqft new home being built. I will have a finished basement (1880sft, main floor 2400sft). I could not afford zoning as the basement would have its own ductwork and that is where the money costs are with the labor. I had wanted 3 zone system: 2up one lower. If I go without zoning I could save $$$ on ductwork BUT as you have read there is no control on the lower level as the therostat would be upstairs. So another option I am looking at is ductless systems for downstairs. You can get upto a SEER 17 now and days. I have 3 rooms and may go with a single system (heat and cool) that supports 3 rooms. I then can control almost like a tankless water heater. When someone is using the downstairs they can turn on and when not in use I am not paying for it. We have a teen for downstairs for one more year then it will be just used for visitors. I will prepare my bonus room for the future by putting in copper pipe now for ductless. You might consider this. I am still in the research and consideration stage. I have seen and they are SUPER quiet. Checkout mrslim.com (Mitsubishi split systems)
Lisa