How to talk to a roommate about the AC (and other things)

Temperature, lights, guests, noise and cleanliness cause 90% of roommate friction. The fix is boring but effective: talk early, talk specifically.

Agree on defaults in week one

AC temperature, lights-out time, quiet hours and guest rules. Write them on a sticky note if you have to.

Use "I" statements

"I sleep badly when the light's on after midnight" works better than "You always keep the light on".

Offer a trade

Eye mask for you, a desk lamp for them. Earphones for calls. Small gear solves big fights.

Escalate kindly

If talking doesn't work, ask the manager to mediate or request a room swap. That's what they're there for.