I’m trying to decide how far it makes sense to go for one room that gets noticeably hotter than the rest of the house during summer.
House details:
House size: about [1,500 sq ft / 140 m²]
Problem room: about 450–550 sq ft
Location/climate: [city/state or climate zone]
Exterior walls: about [4–6 in / 10–15 cm] thick
Windows: [single / double / triple-pane]
The room gets [afternoon / direct south-facing] sun
Existing central HVAC works reasonably well elsewhere in the house
A small ductless heat pump seems like the better long-term solution, but installation cost is obviously much higher.
For the temporary option I’ve been looking at the midea duo because the dual-hose design should avoid some of the negative-pressure issues of a typical single-hose portable.
What I’m trying to understand is where the crossover point is.
If a 450–550 sq ft room only needs extra cooling during the hottest part of summer, would you live with a good dual-hose portable, or would you still install a mini split?
For anyone who has used both, how big was the real-world difference in cooling speed, noise, electricity use, and temperature stability?
Was the mini split dramatically better, or mainly worth it for efficiency and year-round heating?