In our testing using the latest BIOS and 3.10.0 Dell Power Manager Service, all Laptops meet our manufacturer specifications for fan noise levels. All should update to the latest BIOS and install 3.10.0 Dell Power Manager Service. If Dell Power Manager Lite is already installed on your system, you must uninstall it before installing Dell Power Manager.* The AC power adapter must be connected* Open the Dell Power Manager software* Go to Thermal Management* Test all four (Optimized, Cool, Quiet, Ultra Performance)  
I just moved from 7390 to 5320 (but still have 7390, E7240 and E5450 for comparison). Fan in Latitude 5320 is very loud. Extremely loud in comparison to 7390 or any other E series. Such a noise level I remember only from C series. Updating firmware/drivers & changing power management from "Optimized" to "Quiet" didn't help. Fan is not working when CPU load is 2-3%, but when CPU load gets above 8% fan starts to spin. With average 20% load is already as loud as gaming laptop with 1660ti or Latitude C-series. Does anyone have similar issues with 5320? Is the whole series not optimally designed or just this one got bad fan or not enough thermal paste?
Latitude 5320 fan very loud