To remarks,

* in general (warm, cold or moderate climat) : keep the temperature difference (dT= Tc-Tamb) to a minimum, keeping in mind:
- you need a minimum dT to have a good heat exchange
- you need a minimum dp over the expansion valve to keep a stable operation, aspecially on low superheat applications (electronic expanion valves are the solution here)
- small dT means (larger exchange surface and) more expensive condensor, higher content, ....

* the unit for temperature difference is K (Kelvin) (not °C); let's use it, to avoid any confussion

Best regards