Can a upper level, cooling minisplit cool a lower level bedroom in a PHIUS house?
I’m building a 3,000 sqft PHIUS passive house. It’s basically a 2 story shoebox east to west. the main floor consists of a master bedroom (1/3 of the area in from the west wall) and an open floor plan kitchen/great room (2/3 of the area in from the east wall) with an open stairway to the upper floor (along the north wall of the great room). The upper floor consists of the said open stairway across the north wall and a hall with three bedrooms along the south wall.
The cooling load of the whole space is 5000 btu/hr.
I’d like to place a mini-split sized for cooling at the north wall open staircase near the upper level floor (or will it need to be closer to the ceiling to be effective?). There’s a mitsubishi indoor unit that can split blowing directions and blow up and down at the same time. I’m fairly confident that it will be able to cool the upstairs rooms (with the doors open) and the kitchen/great room. What I’m not sure about is if it will be able to cool the main level master bedroom, even if the door is left open.
I understand that passive homes can maintain consistent temps, so I’m hoping it will work, but I’m not sure it will in this case. Obviously adding another mini-split for the main bedroom would be way oversized, so that’s not an option.
EDIT: Amazing community, thanks everyone for your replies!
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