Love it @KarstenI ! I didn't realize we've added Meraki USB fans to our swag lineup, nice!
@cyriel95 here's one of my replies to a similar, earlier post - and I now see there's a better/correct option, LOL:
I don't disagree, the fanless convection-cooled devices run pretty hot, and there's no "thermometer" reading in Dashboard. However the products are designed to withstand that indefinitely, which is why they are covered by the lifetime product warranty. Still, it can be unsettling, they can be very hot to the touch, and we all know electronics don't necessarily like very hot ambient (and internal) temperatures. Like you, I've had stacks of MX64/65 appliances and MS220-8P switches running in my lab for years, stacked right on top of one another, in a poorly ventilated basement storage closet, no issues.
That said, I have had customers with the same concern, such as premature failure due to constant hot operation for multiple years. So I suggested, since they have MX appliances, to use the USB port on the MX to run a low-cost USB powered personal fan like this https://www.amazon.com/ARCTIC-Breeze-Mobile-Flexible-Portable/dp/B003XN24GY/
I got one myself to test and the temperature (between my MS220-8P and pair of MX65 appliances) dropped by an impressive 25 to 30 degrees F. Is was relatively quiet as well. There was no other ventilation in my closet, just this personal USB fan plugged into one of the MX65 USB ports and bent in a loop to direct air across the 3 pieces of equipment. Just a thought, in case you have a similar case with hot equipment and poor ventilation.
Hope that helps!