I'm redoing a section in my house in which I am adding a new kitchen and bathroom. Since the main panel is getting pretty full, I wanted to put in a sub-panel. My house has 150A main panel. House has gas appliances. The only 220V device is the CAC.
My question is are there any rules as to what size sub-panel you can get with regard to what main is feeding it? I wanted to get a 100A/ 20 ckt main lug as the sub-panel. Any issues with this? Or should it be a smaller sub-panel?