[aliher1911]

Possibly 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.

[marcosdumay]

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.

[altern8]

I'm not following, that's exactly what I want, I want the fan control to also turn off/on, so fan at 0 = off, fan > 0 = on.