It would not be fiddling to put another unit in... it would be serious WORK....
You may have been worn out by the AC threads lately.. but the actual systems are very simple and you just need to follow certain rules as if they were sent down from ON HIGH... if you want it to both work well and LAST......
Actually they WERE sent down from his COOLNESS LARRY... so if you just listen to him you will be in good shape...