I have a noisy fan, it gets quieter when the frost setting is turned down

Pay attention to the noise rating (Sones level) when you buy a new one. The lower the number, the quieter the fan. Price is not the only factor as it depends on the size, the air flow, extra features (like heat lamps), and design details. Generally, quieter fans cost more than noisy ones, but an expensive fan can be noisy too.

Some refrigerators control the freezer fan by turning it off when the door is open to minimize cold air loss. This is likely normal for your model (check wiring diagram to ascertain this.) The freezer fan is the noisiest component on a refrigerator so the noise might be typical of your model. If it is excessively noisy (it's louder now than it used to be) then it will probably be one of the following: 1) bad fan motor bearings and the motor should be replaced, 2) loose or broken fan blade and should be replaced, or 3) frost/ice buildup on the evaporator (cooling) coil that the fan blade hits and the cause of the frost /ice should be corrected (likely a defrost problem.)

Some fans are temperature-sensitive, i.e., when the CPU is "hot", the fan spins at high-speed, with more noise. For other fans, you can restart your computer, and enter BIOS SETUP, and set the speed of the fan, e.g., 50% or 70%, to make it quieter.

check the freezer fan, also known as the evaporator fan motor.

You can try using caned air. turn off and unplug the computer then used the caned air on the fan to blow out any dust. plug it back in and power it on and see if the fan is any quieter. If not then it could be that the fan is going bad and may need to be replaced. Most computers will have a coupl of fans, case fans, CPU heatsink fans, videocard fans, power supply fans, so you will probably need to open the case up to get to all of them and make sure they are clean.

Check my tip here first.

http://www.fixya.com/support/r3566188-loud_fan_noise_thermal_shutdown

Hi, The noise from any computer is due to the fan. It is really the only thing that makes noise on a computer - unless you havce a bad drive. If you can hear a drive outside of the case, then it's about to fail. You can buy a quieter fan for your laptop. That will take a bit of investigation on your part, as far as getting the dimensions and wattage of the fan from your manufacturer's web site or the instruction manual that came with your computer. You would do best to go to a reliable and competent computer shop and have a quieter fan installed, rather than doing it yourself if possible. This mod is very simple, and can make your computer run better, provided you get a better fan that can cool your machine better.

I would start with a 24 hour full defrost,
if the problem reoccures then it is more likely thermister fault

Set the projector to "high altitude mode." It will be noisier, but won't overheat. I wonder whether using one of those $10-$20 laptop coolers underneath it might be a quieter solution.

HEY BUDDY...............
U DONT HAVE ANY PROBLEM...IF U R CPU IS PROPERLY  U NEED NOT TO BURRY.ITS OK
AND FAN NOICE DOESNOT MATTER MAN.....MY PC  ALSO HAVE 3 FANS AND CREAT SO MUCH SOUND..............

dont forget to tell me u r problem solved or not
best regards & best of luck..