Hi gengar77, questions you need to ask to assess based on an older AC thread post
1. What's above the unit at the top? Is it another floor e.g. water tangki, sky terrace, bare concrete cement roof or tiled roof or metal roof?
2. Each room orientation where the AC will be installed (all applicable compass points where the walls are exposed and does not border a neighboring unit)
3. Area (LxW) of each room to cool and their ceiling height
4. Semi partition movable (sliding doors) or fixed (wall or tall bookshelf)

Based on the post linked above, calculate the cooling load in BTU which serves as the starting point of what kind of AC HP to get. Being at the top floor, depending on what is above it, sometimes the heat load is increased by 20-30% which means a 1.5HP or 1.75HP will be required. Only Panasonic sells 1.75HP (15,000BTU) but the piping for such is 2HP already.

As an example, say a 5m x 3.5m bedroom on the second (any floor except the top) floor of a multiple story condo. It has large windows facing south on one corner and south west on another. 
Total area (A) = 188.368sqft (17.5m2)
Base HLF (Hb) = 60 _____for condos and ground floor
Additional modifier:
+5 if sun facing area is W,SW or S and has larger than usual fenestration (windows)
+10 if room wall faces W,SW or S (typical corner unit)
Final HLF for this bedroom (Hf) =75
Cooling load required= A x Hf = 14,128BTU

On a clear sunny day, this bedroom will bake her occupants through the night until 3am.

Had the bedroom faced east and the windows are no larger than 25% of the whole wall exposed, it's cooling final HLF would have remained unmodified at 60 which yields 11,302BTU.

Of course, curtains block out the sun and double glazed reduces the heat load.

One more thing: for the same AC pipe diameter, 1 and 1.5HP are interchangeable. 1.75 and 2HP are compatible for 2HP pipes. Some AC units 2.5HP also fits on 2HP. The key is the return (gas phase) pipe diameter. Typically 2.5 or 3HP and above a larger gas pipe diameter is required. So sizing is important if the calculated load is bordering on the next HP which may or may not affect the pipe diameters required and thus expanding or limiting the choices when an upgrade is required. Mitsubishi Electric is one anomaly in which it 2HP typically uses a 2.5HP sized return pipe.

Hope that helps.

Planning to get SHARP AHXP13UXD aircon.

Anyone using this model? any feedback?

[attachmentid=9022700]

SPECS:
EER 13.2
Nett Weight 9 kg (Indoor) / 20kg (outdoor)
ECO Mode Yes
Dual Drain Setting Yes
Dimension (WxHxD)(mm) - Indoor 856 x 290 x 244
Baby Sleep Mode Yes
High-Density Plasmacluster Ions Yes
12-Hour ON/OFF Timer Yes
Running Current - Cool (A) 5.0
Best Sleep Mode Yes
Quiet Operation Yes
4-Way Auto Air Swing Yes
Super Jet Yes
Series Wall Mounted Split Air Conditioner
Airflow Volume - Cool / Indoor 11.5
14m Long Airflow Yes
Refrigerant R32
Horsepower 1.5
Capacity 12,500 (2,860 - 15,000) BTU/h
Inverter Controlled Operation Yes
Dimension (WxHxD)(mm) - Outdoor 598 x 495 x 265
Self Cleaning Function Yes
Power Input - Cool (W) 695
Auto Swing Louver Yes
Power Supply 220-240-1∅-50
Pipe Diameter - Gas Side (Inch) 3/8
Dragonfly Fan Yes
Awakening Function Yes
Voltage Range (V) 198-264
Pipe Diameter - Liquid Side 1/4
Auto Operation Mode Yes
Lock-On Sensor Yes

more in on brochure =>[attachmentid=9022730]

It depends if it's easy to isolate the zones such that each one can cool it down without being overtaxed. I'll prefer this approach too. If you think it might overtax then go for 1.5hp at the crucial one like bedroom. One easy way to partition is to use thick curtains.

Three things to consider:
1. Piping insulation. Individually sleeved per pipe. Use Inaba Denko's (JP) or Smartco's (KR) Paircoil. Sets you back a bit but guarantee will not develop leaks so long as installed correctly. Use 0.8" thickness for R410a which is also compatible with R32. The requirement is to guarantee AC runs at its rated power without which (all in one jacket/sleeve), the mixture causes the compressor to overwork (higher electricity consumption than rated) which can potentially damage the indoor unit cooling fins esp if the piping runs are in excess of 3m. This is evident when there's freezing on the AC cooling fins due to this caused by the compressor overworking to compensate for inadequate cooling capacity. You'll know when you hear the sudden tak tak sound of ice forming and bending the fins. Leaky pipes can also cause this over time. Quite common in old AC but not sure perhaps they've mitigated this now.

2. Piping size - it's ok to oversize such that in future, if you need to upsize, there's no need to hack and repipe. Bear in mind the gas / return / hot pipe should be equal or larger, never smaller than that of that AC model used. For example, 1.5HP on a 2HP pipe or 2HP on a 2.5/3HP pipe. If experience bears out that a 1HP or 1.5HP cooling is insufficient, you can in future swap that out and get a 2HP but without changing pipes.

3. Long air throw. If relying on a single, bear in mind that certain AC have what's called long throw feature like the Sharp inverter (14m even on a 1HP) or a Mitsubishi Electric Mr Slim. The Sharp has a ceiling throw mode for gentler cooling too.