I am getting this error randomly and not sure as to why my disk space is getting low for Android Studio..
Low disk space on a Android Studio system direct
You can install studio and SDK separately into different partitions: http://developer.android.com/sdk/index.html#Other
Or you can move your existing SDK folder anywhere and then just point studio to it in preferences.
Also consider that AVD files are actually stored in your system user folder (user/.android/avd
on Windows, not sure where exactly on mac), not in SDK folder.