I have a cabin that has 100 amp service. All the breakers are in use. I would like to install a/c and need 2 breakers side-by-side. I have a 20 amp circuit with only a microwave on it and a 20 amp service with only a refridgerator on it and a 20 amp circuit with 2 GFI outside boxes on it and a 20 amp circuit for the bathroom that has 1 gfi, 1 outlet, 1 fan and 2 lights. Can I combine some of these to open up 2 circuits for the a/c? The outside GFI's don't get much use, the microwave gets some. The bathroom and fridge get the most use. What are the best combinations?