Yes it has a fan that turns on at 100w.  Can you hear it?, of course, it's a fan. Is it a hurricane? No. With a constant 150w load it's stone cold, so if it bothers me I might look at how to change the load switch for the fan, but I think in a cabinet it will do fine.. For those commenting about build quality never having seen it, as I said, it built like a GoPower, so not bad. The normal store price is $150, not $40. It has a soft start and can surprisingly light a 300w lamp. The inverter doesn't care and handles it fine. My 12v power supply hates it tho. This is a clearance sale, that's the reason for the price. For those looking online, obviously that doesn't work as has been proven several times on this thread. Pick up the phone with the stock number and ask. My local store has a stack of them, I'm sure many more do as well