There is always going to be an element of unwanted alarms caused by this in hotels, as standard smoke sensors are basically just doing there job.
Something on the back of the bedroom door saying about the sensors are very sensitive etc might be a good idea, and even on the desk adjacent the bed, just incase they dont look on the back of the bedroom door indicating this, may reduce this slightly.
Is a common problem across hotels, with smoking in potentially a confined space.
Bit of a tricky one, but there are always some people who wont risk the rain for a sneaky cigarette. But on the other hand it's weighing up the risk of a potential fire in the room and the loss of life against this.
You don't seem to have the problem of steam from the bathroom causing false alarms on the detector head, which can also be common, which shows good progress.
