Hi Star, Some fans are, and some fans aren't.. And, a fan controller will help, just by reducing the speed (and noise) of the fan. I had to add some rubber washers to the wall mount of mine- that reduced noise to a whisper, from a loud purr. I know Grozone makes versatile fan controllers, but I'd recommend getting a "right sized" fan and carbon filter, and see if a controller is needed. A bunch of folks build a box around their fan, if needed, too.
Btw, lovely little Ladies you're growing

My Blue Velvets and Durban Autos are at the same age- just about to really take off, too. Best to you!