What HVAC system to install "in general"

[huntj.srhs]

I have read much of the postings. Mostly all of them scream "load calculation." We will break ground for our new home in 1 week. The house is 2,591 sqft heated space. The 1st floor has 1,358sqft, 2nd floor has 894sqft not including the bonus room which has 339sqft. The house will be shaded throughout the day because it was a wooded lot and we left all the trees we could. Also, the house has lots of windows. Now, here comes the stupid question. How much HVAC should I plan for in general. Maybe one big unit or two smaller units. How about a split unit for the upstairs? I don't know. Oh, we are in NC just across the line from SC. So, you can imagine that the weather is always fine here :D Eagerly waiting for your reply.

[Crash13]

I'm building a similar sized house right now, except my first floors is larger and my second floor is slightly smaller. I decided to go with a geothermal system because I'm in michigan. On the NC / SC border you could probably just use a plain heat pump, but geothermal would still be more efficient. The price increase to go from a standard heat pump to a geothermal heat pump is probably too much to warrant the upgrade, but it may be something to look into. Anyway, when i was doing my research I talked to a guy that built a 2800 sqft colonial and he just used a 4 ton single zone geothermal system. So I think your 2500 sqft would probably just require a single zone system as well. I don't know much about heat pumps as i did all my research on geothermal, but if you are interested in geothermal at all I can help you out a little.

[huntj.srhs]

"Geothermal" it even sounds costly. I'm positive that I can do just fine with a standard system. At least, that's what everyone else is doing. Anyway, back to my original question. Would my design warrant one or two units to maximize efficiency? Once again, the site is shaded and the climate is normally mild. What might a ballpark figure be? Does anyone want to try an educated guess? I will see 3 HVAC persons within the next week and will get back with their recommendations.

[rabadger]

First things first :!: The only way to know is by the load calculations. You have to create a level playing field for all the bidding constractors.

I am currently doing one in southwestern NC and one in northwestern SC.
The square footage on both jobs are about the same but do to construction materials and general location the HVAC loads are not even close to each other.

Square foot sizing is a no-no!

You can't start looking at equipment choices without knowing the requirements first.

[huntj.srhs]

I saw one of the HVAC guys today. He said that he could easily meet the needs of my house. He has been in the business for over 25 years and has many local customers. He said that he would supply a 2 1/2 ton on the 1st floor and a 2 1/2 ton on the upper level (split). The units would be Janitrol and 12 sears. He said that the job would be A+ and that he would warranty the service for 1 yr all parts and labor. The unit would then be covered for 10 years at parts only. Cost: $7,300.00 Sounds like a deal to me. I have read of systems costing well over 12-15K. I don't think that I would ever pay that for a system in this location. The county in which I live is trade heavy (construction, HVAC, etc). How does the specs and price sound. Is it adequate?

[rabadger]

You met with him this AM and already the systems are priced and quoted that afternoon. Did he show you the load claculations and explain why they needed to be done? Good luck