Mini heat pump per room?

[dfhuynh]

Hey all,

I'm a newbie, thinking of how to heat/cool a new house to be built in Northern California where the temperature ranges from 45F to 105F. I'm hoping to get some opinions here about my plan--whether or not it makes any sense. Thanks in advance!

The new house will be 2-storied, around 2800 sqft including a 300-sqft Accessory Dwelling Unit for rental. The first floor has a "big room" and a guest suite, and the ADU. The second floor has 3 bedrooms of various sizes, from 150 sqft to 400 sqft.

(Of course, I'll have good insulation, so this is on top of that.)

I'm thinking of having a gas furnace to heat mainly the "big room" on the first floor (with some effects on the other rooms). The furnace should help get the other rooms to about 64F ~ 66F in the winter. In the summer, I plan to have an A/C unit to cool mostly the big room for family activities; it should help get the other rooms down to 76F ~ 78F. Then, in each of the bedrooms, I have a small 9000-BTU 700~900W heat pump to get the room's temperature to a comfortable level (68F ~ 72F) only when it's in use. I expect just 2 of the 4 bedrooms to be in use year round, whereas the other 2 will be used by visitors for maybe 2 months per year.

The ADU will be on a separate power sub-panel and completely electric (no gas). It also has a 9000-BTU 700~900W heat pump that's good for 400 sqft, for both heating and cooling.

Does this plan make any sense, environmentally / financially? Any concern if by chance all of the heat pumps are on at the same time?

Thanks,

David