I am in the process of renovating two-story with basement house that is located in Albany, NY. Currently, one central air gas furnace/AC unit located in the basement serves both the first floor and the second floor.
Renovations will include adding spray foam insulation to all walls (there is no insulation in any of the walls), replacing all single-pane windows with double-pane energy efficient models, converting the attic to a conditioned space for storage use, and finishing the basement.
Renovations on the first floor require two walls to be removed, which necessitate removal of supply ducts to two of the the four rooms on the second floor.
The architect recommended separate HVAC systems for second floor/conditioned attic and then a separate unit for the 1st floor/basement.
Manual J calculations were done for the planned post-renovation loads.
The combined second floor/attic heating/cooling loads after renovations is expected to be 7,495 cooling and 13,145 heat.
The combined first floor/basement heating/cooling loads after renovations is expected to be 8,020 cooling and 13,835 heat.
Due to the difficulty in finding a standard furnace/AC system that will serve such a low cooling load, my HVAC consultant has proposed the followng options, ranked in terms of comfort:
1. Two single-zone concealed-duct Heat Pumps: One unit in the attic that will be connected to a standard supply/return duct system located in the conditioned attic, and which will serve the second floor and attic conditioned space; plus, a second unit in the basement that will be connected to a standard supply/return duct system that will serve the 1st floor and the basement.
2. A single central air/furnace located in the basement with a zoned system with zones for the first floor, basement, and second floor. Floor space would have to be sacrificed on the first floor in order to run new supply and return ducts from the basement up (to replace the ducts lost during the renovation).
3. A non-zoned single central air/furnace located in the basement that will serve the first floor, basement, and second floor. Floor space would have to be sacrificed on the first floor in order to run new supply and return ducts from the basement up (to replace the ducts lost during the renovation). Heating cooling loads would be 29,980 heat and 15,156 cool.
Note: The wife flatly refuses to consider wall-mounted split units or window-mounted air conditioners (she doesn't even like looking at current HVAC supply/return vents).
Any comments on the options, or are there any other options that should be considered?
Thanks.