Make sure to get the right size A/C unit for your space. These are measured by capacity and BTU.
What is BTU?
BTU is an acronym for British Thermal Unit.
You get this by measuring the length and width of the room and multiplying it by 25. This will give you a rough size. Now take into consideration, if the room gets a lot of sunlight add 10% and if there is a kitchen in the room add 4000 BTU. If there will be more than 2 people in the room add 600 BTU per additional person.
To get the physical size of the unit you need, measure the opening of the window or wall.
The outlet should be the standard 115V or 208 / 230V.
Wall AC install through a wall of a building and require a wall sleeve.
PTACs are Package Terminal Air Conditioners are self-contained heating and cooling units mostly found in hotels, apartments, condo, and hospitals.
Like Wall A/Cs they require a sleeve. All PTACs require 208/230 volts or higher to work.
Cheat Sheet Guide to Calculating BTUs