What are you using to control the AC (Arduino/ESP/ETC).
What are you expecting to control the AC with from the internet? Will you be using something like a phone app or some other method.
There are several cloud based services that are free & not difficult to get working. Cayenne & ubidots have online dashboards so you can both monitor and control from the dashboard. Another option is to use dweet.io to pass messages/commands between devices over the internet. I use it to post sensor messages from home so I can view them at work (without exposing my home network) and also to send commands to the sensors.