deleted files go under "other" instead of being deleted for real

I have a problem when deleting files. if i empty the trash instead of getting more hd space the files apparently get saved in the "other", i dont know how to change this...

i just deleted 60gb of data from the hard drive (i emptied the trash), but half of it went to the "other" space...how do i delete for good these files?? cos now i dont even know where they went now... before emptying the trash the "other" space was 140gb approx, after deleting it went up to 175gb!