alt Hacker NewsPossibly a consumer air dryer problem, something-something safety. Check professional ones like Parlux, the one I checked has 2 dials: airflow and temperature. Turns on by air dial. They are also conveniently under the thumb so you can adjust without looking.
Yes it's safety related. Turning the heater on while the airflow if off is a sure way to start a fire.
It could be fixed with a relay or a solid state switch on the heater, or with a multipolar toggle on the airspeed. But that's several cents more expensive than making it turn on at the heater switch.