A quick search for 2 channel 24v fan controller yealded the below link. Not saying this is ideal for your scenario but something similar will work and can be powered with a power brick. Doesn’t look like it comes with instructions though so I’m not sure what current it requires. The temperature sensor could work to make it turn on when the printer heats up as well.

https://www.amazon.co.uk/Channel-Temperature-Controller-Governor-Display/dp/B083R97GZ1