CiaranMcNulty parent
I could count the number of times my M1 (13") MBP's fans have kicked in over the last year on two hands, and in most cases when I investigate there's some rogue process running thrashing some of the cores (looking at you, Fusion360)
My experience with the Mac Mini M1 is the same. We bought a Mini for our daughter. I use it sometimes to benchmark stuff on the vanilla M1. I don't think the fan every spun up.
I can get the fans to spin up easily on my MacBook Pro 14" (M1 Pro), e.g. when building a large project like PyTorch. Luckily, the fans are not very loud. I can't hear it at the office (plenty of ambient noise), though I can hear it sometimes in our home office.
Passive cooling is one of the reasons I recommend people to get the M1 Air, unless they need 8 performance cores or > 16GB RAM. A completely quiet laptop is such a nice feature. I hope that they keep the Air passively cooled in the future.
Edit: >= corrected to >