How long have you had the device? Seems like a good bang-for-the-buck device, but details are hard to find. It's not available in my country whatsoever. It seems to be a cooling issue, but I would check out the temperatures before doing anything else. The thermal paste should be good for a device under 2 years of age. Check the temperatures, if it persists and the device is still under warranty, contact your supplier for support. If they're giving you a hard time, contact HP support.
Especially if a device is under warranty, don't disassemble the device as you'll void your warranty. Since you said the fan only spins down when it's at or under 10% utilization, the only thing I can think of is a thermal issue, which will require to...