Capacity and Room Size
Portable ACs are rated in tons, same as split ACs, but they cool less efficiently per ton because the compressor and condenser sit inside the same unit as the fan. A 1 Ton portable AC is generally suited to a small bedroom, study, or home office, roughly up to 120 sq. ft. under normal Dhaka summer conditions.
If your room is larger, gets direct sun, or has poor insulation, a portable AC will struggle and run almost constantly, pushing up your electricity bill. In that case, a Split AC is the better long-term choice.