The A/C will preform at it's best when installed so the bottom of the a/c is at eye level. Cold sinks, so the higher up the better. This also makes maintenance a lot easier.
Side By Side:
The CoolBot should be mounted inside the cooler next to the AC. If there is a troubleshooting issue, you have to have the CoolBot and air conditioner right next to each other.
Note: If it's an issue of wanting to know the temperature from outside, there are pretty cheap ($19) wireless temperature sensors you can get from Amazon -- and basic wired thermometers. About $12 from WalMart/Home Depot, and more expensive ones ($80) you can monitor on a smartphone or online.
Also, CoolBots can't be in direct sun, so if you still decide to mount it outside, you'd have to protect from that as well.