I am starting to get bids for a HVAC system for a new 2 story home we are building in the Seattle area. We are going with radiant floor heating, but would also like AC. One of the companies bidding on the job suggested running ducting to only the 2nd floor, stating that the 1st floor would only be a couple degrees warmer than the 2nd due to the fact that heat rises and is also drawn to the cooler air. The system would be sized to cool the 2nd floor, plus a little extra to handle the extra heat coming from the 1st floor.
We have a very open floor plan with a cathedral ceiling extending from the 1st floor to the 2nd floor, so it doesn't seem like airflow would be a problem. Does anyone have any experience with this type of setup? Is this a good idea or not?
I appreciate your enlightenment.