Laptop overheating and noisy fan: vents, dust and power settings

Unplug the charger and switch the device off. Never puncture, bend or heat a swollen battery.

Unplug the adapter or the plug from the wall socket before checking anything. Make sure your hands and the work surface are dry.

Clean the vents only while the laptop is off and the adapter is unplugged, and let the case cool down before you handle it for long.

A laptop fan keeps the temperature inside the case stable. According to ASUS, its speed follows the temperature of the processor and the graphics card. When the laptop runs heavy programs such as games, video editing, file conversion or large data calculations, the temperature rises and the fan spins faster to get rid of the heat. A fan that sounds loud at those times is normal behavior.

The reverse is normal too. ASUS writes that on some models the fan does not spin at all while the laptop is idle or under light use, until the system temperature reaches a certain level, to save energy. A fan that keeps running after the laptop goes to sleep is also normal, because the processor is still working in sleep mode. If you want the fan to stop completely, ASUS suggests hibernation or shutting the laptop down.

What needs checking is a fan that stays loud while you are only typing or browsing, or a case that feels very hot. A laptop that slows down or shuts itself down from heat also needs a look.

ASUS groups the causes of an overheating laptop into four. First, apps that use the processor or memory abnormally. Second, dust built up inside the case or in the vents. Third, an unsuitable environment. Fourth, a fan that slows down from wear after long use.

Open Task Manager in Windows, then look at the CPU and memory columns. ASUS suggests this step to find apps that use more resources than expected. A process that keeps taking a large share of the CPU while you are not running anything heavy is the likely suspect behind a fan that is always loud. Close that app, then see whether the fan slows down within a few minutes.

After that, update the BIOS, Windows and drivers. ASUS puts these updates first in its guide, because updates improve system stability and performance, fan control included. On an ASUS laptop, driver updates are available through System Update in MyASUS. Other brands provide their own update apps.

If the heat started recently, for example after you installed a certain program, ASUS suggests a System Restore to a restore point from before the problem appeared.

Dust, hair and cigarette smoke are the fan's main enemies. ASUS writes that tar from cigarettes sticks to the fan blades and the heat sink fins, and that oily layer then attracts dust and hair faster. Blocked vents make the fan work harder while the heat stays trapped.

1. Turn the laptop off and unplug the power cord before cleaning, as ASUS asks.
2. Find the exhaust vents. On a laptop they are usually on both sides of the case; some models put them at the screen hinge.
3. Use a can of compressed air from any store. Spray it from a distance into the vent, and do not turn the can upside down while using it.
4. Do not use an air compressor. ASUS reports cases of fan blades damaged by too much air pressure.

This only cleans the outside of the vents. If dust has built up inside the case, ASUS recommends contacting the ASUS customer service center.

ASUS says to use the device at a room temperature of 5°C to 35°C, in line with the safety instructions in the user manual. The laptop also needs a hard, flat surface such as a desk, not a sofa, pillow or bed that covers the air intake underneath.

Working in bed or with the laptop on your lap on a sofa is common in many homes. Fabric and foam cover the air intake, so the fan spins hard but gets no fresh air. If you have to work in a place like that, ASUS suggests a cooling pad or a stand that lifts the laptop so it does not touch the surface directly.

Leave space around all vents, including the side where hot air comes out. Keep books, bags and walls away from the front of the exhaust.

Most ASUS laptops let you pick a fan mode in MyASUS, to balance performance and temperature for the workload. Open MyASUS, select Device Settings, then look for ASUS Intelligent Performance Technology. Some models show Fan Mode instead. ROG and TUF gaming laptops control the fan through Armoury Crate.

Windows also has a power mode that balances performance and battery. Open Start, Settings, System, then Power & battery, and choose a mode under Power mode, separately for Plugged in and On Battery. Microsoft describes three options: a power efficiency mode that saves battery life, Balanced, and a performance mode that maximizes performance.

If you cannot change the power mode, Microsoft says a custom power plan might be selected. Open Control Panel, System and Security, Power Options, then select Balanced.

An ASUS laptop can check its own fan. Open MyASUS, select System Diagnosis, then under Diagnostic Tool tick Fan and click Checkup. The diagnostic options can differ between models. According to ASUS, if System Diagnosis finds no problem, the hardware is working normally; if it finds a problem, the fan needs replacing at an ASUS service center.

Other brands usually have a built-in diagnostic tool that does the same. Note the test results before you take the laptop in, so the technician knows which parts have already been tested.

Take the laptop to the authorized service center for its brand if:

• dust has built up inside the case, which ASUS says should go to its customer service center;
• the fan diagnosis finds a problem, or the fan does not spin while the case is very hot;
• the fan sound changes to scraping or rattling;
• the laptop shuts itself down from heat even with clean vents and heavy apps closed;
• the bottom case or the touchpad looks raised, which can point to a swollen battery.

Opening the bottom cover, cleaning the heat sink fins inside and replacing the fan are jobs for a technician. There is a lithium battery inside the case; opening the battery pack or replacing the battery cells is not something to do at home. Back up your data before you hand the laptop in.