[Nightedge]

situation:

John and Peter are living in the same room as classmates, but since Peter comes from a poor family, he cannot give money back to his roommate even if the roommate incurs expense from/on/in/at air-conditioning. What should he say?:

-I am sorry that I can't reimburse/recompense/compensate you for expense from/on/in/at air-conditioning.