I suffer from asthma especially overnight; I’ve used this fan over the last week and I haven’t woken with any coughing etc. since! Similarly, the fact it has auto mode ensures it’s only on when it needs to be and keeps as quiet as possible. It has really made a difference in my sleep schedule. On colder nights the heating really nice, I would recommend to turn it on and set it to a desired temperature about 30 mins to an hour before you go to bed so you have the most comfortable sleep on a cold night. Seems quite efficient too, great stuff all around!