Time away at school is considered time living at home so you can claim him if the other qualifications are met.

YES, you can claim your son as a dependent child for the following reasons: 

1. He is under 24 and a full-time student.
2. Time away at school is considered as living at home (as indicated by @Bsch4477). 
   

But before you go ahead and claim him as a dependent, read the following list to determine if all requirements under qualifying child are met. 

https://ttlc.intuit.com/replies/5187060