How many zones in our home?

[mjconsumer]

Building new open concept home like a barn structure/post and beam interior. The basement is connected to first floor with large open stairway. 2nd floor is open to the first. Does GEOThermal unit work better/more efficiently as just 1 zone or can we get away with 2 or 3 zones? We initially wanted a zone on each floor, but have heard that geothermal units/pumps work much more efficiently on a single zone. Any thoughts/opinions would be greatly appreciated! In addition, would there be a big cost savings if we went from a 3 zone to a 1 zone system?

[D-Allen]

Your application may call for 2 systems. Upper level could be a split geo.

[skeller]

I'm doing a Geo job that has a 5 ton unit on first floor and 3 zones. If the right zone system is used. Jackson systems and arzel systems, I think are some of the best. They have a modulating bypass damper that will help keep the correct air to each zone. On the unit, go with a 2 stage variable speed unit. This will help on utilities and load demand. Just make sure unit is designed for full load. Need anything else, I'll be glad to help

[EnergySmart]

Geothermal systems work well with zoning. They have controls that can reduce or increase the fan speed based on the size of the zone.

Thermostat location will be important for this style of house. For example, if you put the second floor thermostat in the 'open' area, that zone will not call for heat often in the winter. You might consider putting this thermostat inside one of the rooms.

A split system sounds like a good idea for the second floor.

[SkyHeating]

Where is the home being built? You should look at a two stage unit like a WaterFurnace Envision unit with a WaterFurnace inteelizone panel that will only run the unit in low stages if certain zones are calling for heat and only run at full capacity when all areas need heating or cooling.

[SolarMike]

Is it a ducted system? If it is floor heating or a combination of ducted and and floor heat, put in a buffer tank (100gal+) then run to fan coils and floors. HP will work very well.