What size window unit?
Answers:
Should not be a problem. The lower voltages you are referring to are often times commonly expressed as 110v / 115v or 120volt. They are all one in the same. The big difference is the 220 volt power requirement appliances. Clothes dryers, some air conditioners, electric ranges (stoves), etc. These all have a different (and much heavier) electrical cable and plug-in on the end. The differences in the two are obvious when held side by side. And, the outlet for the 220 volt appliance is configured (shaped) totally different. It is almost impossible to plug the wrong one in.
Other answers:
They are one and the same,so the answer is yes
They are one and the same,so the answer is yes
Always use a dedicated outlet for the a/c, fed by a single 20A breaker. If you don't have a dedicated outlet, be sure to know all the appliances connected or that can be connected to the same circuit you are going to plug your a/c. If you are using your new a/c and turn on a hair dryer or other high consumption appliance in the same 115 Vac circuit, the breaker will trip. You can use your a/c safely but remember not to connect other high consumption appliances. Do not increase your breaker capacity (20 Amp to 30 Amp) before checking your existing wiring rating.