Help with oxygen block counting

Hi,

I have been making a mod with a lot of different stuff and one of the things I'm trying to make is a space dimension. I have created the space dimension and it all works fine but I want players to suffocate unless they are in an enclosed room and have an oxygen generator in the room. The oxygen generators can work along as you have 1 for every 100 non-solid blocks. I can't seem to get the generator to check if it's in an enclosed space though. All the procedures need to be related to that 1 generator, please. Any help would be appreciated.

Thanks.