claiming dependent who is a student

My daughter is 18 and starting college next month where she will live on campus. Her father wants to claim her as a dependent to be able to claim head of household for himself. My first thought is that she hasn't lived with him for half of the year. That leads me to think when she lives on campus she won't live with me for over half the year either. How does this work in terms of claiming her for head of household when she is a full time 18 year old college student? Thanks!