drugdoc

what is location? you have access to nat gas?

you will always have better control and comfort with two systems in a two story.

however, if I was going with one system, I would only consider Carrier Infinity with Infinity zoning controls or same from sister company Bryant. Dealer must be qualified with zoning controls, sizing, and ductwork design sizing. I would not even consider the shortcut steps your dealer has offered.

IMO

I'm with tigerdunes. Know that the Infinity zoning controls may cost more that 2 separate units.

Don't cheap out on this if you are building a long term home. I still can't believe people do option 1 - it isn't code in my state.

I'm also with tigerdunes, however I would go a step further. Since you're planning to be there a while, I would suggest exploring a split geothermal heat pump (with desuperheater & buffer tank for domestic hot water) with the above aforementioned Carrier Infinity fan coil unit Infinity T-stat & Infinity zoning, HRV (or ERV) & electronic air cleaner if neccessary.

IMO

SR

tigerdunes - I'm sorry. I should have specified. We are building in SouthEastern WI. We do not have natural gas available. It will be LP.

I appreciate your insight.

If the Infinity zoning controls cost more, would we be better off just going with the 2 separate units? I know the contractor is planning to use Bryant products. Would their Evolution system be similar to the Infinity zoning or am I looking at the wrong thing?

The contractor described the 2nd option as a basic motor attached to the dampers that can be operated from upstairs. He said it would cost $1200 more than the manual option. Is that what the Infinity control does and what it might cost? Could he be talking about something else?
As he was talking about the 2 system approach he mentioned that although it is a higher cost upfront ($3000), this 2-system approach would use less gas and could make up that difference in ~8 years. Is that possible?

Bryant Evolution is the same as Carrier Infinity

If you don't have access to natural gas, you need a high efficiency heat pump. Wisconsin can be cold. You might be best off with 2 systems. Costs a bit more but you'll have ultimate control and redundancy.

If one unit stops working in winter atleast you won't be completely out of luck.

Propane is very expensive I hear. Definetly go with high efficiency air-source heatpumps. Auxiliary heat should be electric.

Geo-thermal is good if you can afford it but it can be expensive in my area. THere is very few contractors in my area that can work on it. Air-source heat pumps typically only cost a few hundred more than the same model straight A/C.

I'll be the contrarian here. I like the single system with manual dampers in the basement.

Our old house is a two story with manual dampers in the crawl space. That simple system allowed us to evenly heat and cool the home with a single unit. However, the crawl space part was a twice a year PITA.

Our new home is a passive solar walk-out basement ranch. We have a single system with a conditioned basement. We have supply and return trunks to both the main floor and the basement. All four trunks have dampers. This allows us to balance the house nicely.

We are able to circulate air throughout the house using the HVAC equipment, even when it isn't heating or cooling. This helps even out the temperatures and humidity levels between the main floor and the basement, which does not need a dedicated dehumidifier, even here in the South.

We also have an energy recovery ventilator (ERV).

Automatically zoned systems are much more complex than manual dampers, requiring dump zones or bypasses. They are also more prone to failures, can waste energy, and require much more expertise to install and service.

They do have one positive attribute. They provide redundancy. In a primarily heating climate, a wood stove can provide the backup heat source instead, if you like the idea of heating with wood.

My $0.02.

Make that dual systems that provide redundancy, not automatically zoned systems.

The infinity system is an automatic zoned system. There is so much more to it that you describe. But from the user standpoint, I'll give some examples.

Each zone has a stat. The master stat can change temps for the different zones. Each zone can turn on the system. A basic manual damper system might only direct air when the system is on but couldn't turn the zone on from anywhere.

The best example is with basements in shoulder seasons. We don't run the heat here in late March but the basement is cold still. In a simple system, the basement dampers might be all open but it can't call for heat so it stays cold. Now in January, it can direct all the heat it wants (to a limit) down to the basement so it is fine.

The Infinity system measures the pressures in the air handler and cuts down the motor if they get too high. So if a small zone is calling for heat, it runs the motor at a lower speed. This eliminates the need for dump or bypass zones.

Inifinity stats are small computers that are shockingly more sophisticated than the stats you see in 95% of homes. Not simply programmable but a lot more. They have LCD screens and menus. They tell you when the filters need to be changed. They have digital humidity readouts. They can set heat pump/furnace cutoffs. etc etc

The zone dampers on an infinity system relay back their position to the controller. So it isn't a simple relay and a command to open a damper. It is a nearly foolproof system.

No one can give you an Inifinity system for $1200 unless they don't know what they are doing and lose a chunk of money. I paid about $3000 per floor.

Thanks for your responses. Geothermal installers and support are scarce in our area. We are leaning towards the dual system approach. Even though it costs more, it seems as though it will provide us with the best control and is probably our best option.