Why is my fan so loud?

clean your acer nitro 5 fans, it will be so good. I once had that problem and after I clean my fans from all dusts ; it becomes super quiet.

My Nitro 5 had the same issue. Bought a powerful laptop cooling fan, but noise was just as bad. Bought a small bottle of Compu-Lube lightweight lubricant. Added 3 drops to moving fan, but not much better. Then I got lucky. I removed the four teeny-tiny screws that hold the fan cover tightly against the moving part of the fan (photo provided). This did not make the cover fall off, because the routing tape that brings cool air in through the vents holds it down just fine. Removing those 4 screws did the trick, fans are whisper quiet now. I still hear them, but no more buzzsaw noise.

I have Acer Nitro 5 AN515-53-52FA and one of the fans was making horrible noise. Using the NitroSense app I determined it was a problem with the GPU fan. I opened the case, sure enough it was very dirty. But cleaning it did not resolve the noise problem. I took a chance and decided to disconnect the GPU fan. It worked out beautifully, the CPU fan is sufficient to keep the laptop cool and quiet. Temperature stays about 72c on CPU and 46c on GPU. However please do not disconnect both fans, I tried it briefly and the CPU will overheat and shutdown.

This particular model as well as some of the Others in this line up choose to omit a heatsink on the IC that controls the Fans. The Temp on that Chip controls the fans as well. When a certain temp is met it ramps the fans to 100%. Even when directly writing to the addresses on the IC it overrides it to whatever it wants when it wants. It's a baked in function that cannot be disabled afaik. The solution is to get cooling to it. You can either scrap off part of the heatsink coating and epoxy a short heatpipe bent to shape or use adhere a copper shim to bridge to the heatsink. a tiny heatsink added to the die will not work unless you have a fan pointed at it. I ended up using KPx, a copper Shim, some heat pads and thermal adhesive on mine to mostly solve the issue. it still occasionally hits that threshold.