
Midea
Duo Series
Cools large spaces well, but fragile window tabs.

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Midea or clones there of. The model with the big giant oval hose is really a 2 hose model. If you have electric heat that you pay for, get the heat pump model instead. It absolutely cranks out the warm down to -5C. Then rely on your electric heat for the coldest days.
The first rule of portable air conditioners is get a 2 hose model (or the Midea with the giant oval hose that is really 2 hoses. 1 hose hose models are an america only thing. They blow out the very air you are trying to cool. The only reason they exist is 'stupid people are confused by 2 hoses'. 2 hoses balance the pressure and use outside air to cool the condenser. They are the correct choice.
I had the exact one for a year and returned it. It never really worked properly. Maybe I got a lemon but I exchanged it to the Midea 14000 BTU and no complaints
I also have horizontal windows! I have the Midea Duo and I love it. Super quiet and efficient. The remote acts as a thermostat too. It does need line of sight and it’s a bit finicky but that’s my only complaint.
I have both, the Midea is going to be best for your situation, it has more of a variance in capacity than the Hisense, Hisense tops out at 12000btu but is rated for 8000, Midea tops out at 16200btu but is rated at 12000. Also, the Midea has a drain pump to pump the condensate out which is especially important in the heating mode, specially if it is going to go into a defrost. Overall, I think the Midea just has overall better functionality and futures than the Hisense and is closer to a mini split. The Hisense is perfect for my smaller rooms though.
I have the Midea. Combined with the inadequate central AC in the bedroom it's in, the room got down to a lovely 62 degrees last night. This is in Alabama.
i got this like last week! working great!

Midea
Duo Series
Cools large spaces well, but fragile window tabs.

Midea
4-in-1 PortaSplit 3.5 kW Portable Air Conditioner and Dehumidifier
Energy-efficient split system, but bulky with frequent drainage.

Midea
PortaSplit 8K
Powerful split system, easy setup, but needs frequent draining.

Danby
14,000 BTU (12,000 SACC) 3-in-1 Portable Air Conditioner with Inverter - Dual hose / Remote / Wi-Fi (DPA120CBIMBDB, DPA120CBIMBDB-RF)
Very durable, long-lasting, smart Wi-Fi control.

Whynter
ARC-1230WN
Efficient, dual-hose, no water draining, with Wi-Fi.

Ranked #1
Midea - Duo Series

Ranked #1
Midea - Duo Series

Ranked #1
EcoFlow - WAVE 2 Portable Air Conditioner