Indoor, outdoor?
Without knowing anything about how many animals you are wanting to mist.....
Hardware/garden/online stores always have a decent capacity hand pump mister. Like the kind used to chemically treat a garden ect...
For the price I think it's a happy medium. Pump it once or twice a day and maybe replace the nozzle(or delivery system
All together )
No electricity, cheap , quiet, portable, cheap, get some exercise..... And they're cheap