A constantly running Mac fan can be annoying and worrisome. Fortunately, there are several steps you can take to stop your Mac’s fan from running non-stop.
Why is my Mac fan always on?
There are a few common reasons why your Mac’s fan may be constantly spinning:
- CPU overheating – The CPU generates a lot of heat when working hard. If it gets too hot, the fan spins fast to cool it down.
- Dust buildup – Dust and debris can clog up the fan and heat sinks, reducing their cooling efficiency.
- Resource-intensive apps – Apps that use a lot of CPU, GPU, and RAM can cause the fan to work overtime.
- Background processes – Lots of background processes can add up and force the fan to spin constantly.
- Hardware problems – Issues with the fan itself, thermal sensors, or heat sinks can lead to constant fan activity.
How to stop Mac fan from running all the time
Here are the top techniques to stop and prevent a Mac’s fan from running constantly:
1. Quit resource-intensive apps
Apps that consume a lot of CPU, GPU, and RAM resources force your Mac to work harder, generating excess heat. Quitting these apps gives your Mac a break and allows it to cool down.
Some common culprits include:
- Web browsers with multiple tabs open (Chrome, Safari, Firefox)
- Video and photo editing software (Final Cut Pro, Photoshop)
- Games and other graphics-intensive apps
- Productivity suites (Microsoft Office)
- Virtual machines
Check Activity Monitor to identify processes using high CPU, energy, or memory, and quit those apps. This simple step can go a long way towards giving your Mac some breathing room.
2. Close unused tabs and windows
Open browser tabs, documents, and app windows can be taxing even if they’re idle in the background. Closing unused tabs and windows frees up system resources and prevents overheating.
Browsers like Chrome are particularly notorious for high background CPU usage. Regularly closing inactive tabs can help cool your Mac.
3. Force quit misbehaving apps
Sometimes apps misbehave and consume high resources even when not in use. You can force quit them to curb this behavior.
On your Mac:
- Press Command + Option + Esc to open the Force Quit menu.
- Select the misbehaving app.
- Click Force Quit.
This will terminate the app and any runaway processes so your Mac can regain control.
4. Disconnect peripherals
External devices like hard drives, printers, and webcams can subtly increase workload and heat. Disconnect peripherals when not in use to eliminate their load.
USB-C and Thunderbolt 3 accessories tend to use more power and run hotter. Unplug them when not needed.
5. Update apps and macOS
Outdated apps and an old OS version can hog resources due to poor optimization. Updating them improves efficiency and prevents overheating.
Always apply the latest macOS updates for bug fixes and performance improvements. Also update apps like web browsers, Office suites, Adobe CC, etc.
6. Turn off background app refresh
Many apps automatically refresh content in the background, which continuously taxes the CPU and GPU. You can turn off background app refresh in System Preferences > General.
This prevents apps from updating when not in use, giving your Mac a much needed break.
7. Adjust Energy Saver settings
The Energy Saver settings control your Mac’s power usage, performance, and fan activity. Tweaking them can reduce fan speed and heat generation.
In System Preferences > Energy Saver:
- Select “Better battery life” to limit performance and heat.
- Uncheck “Automatic graphics switching” to prevent GPU from kicking in unnecessarily.
- Slide the sliders towards “Better battery life” to slow the system and limit heat.
8. Avoid resource-intensive settings
Graphically demanding settings like high brightness, resolutions, and refresh rates make your Mac work extra hard. Lower these settings to ease the load.
- Reduce brightness below 75% and auto-adjust it.
- Use 1440×900 or lower resolution on Retina displays.
- Limit external display resolution to 1080p.
- Set external displays to standard 60Hz refresh rate.
9. Clean up your Mac
Clutter and outdated files bog down your Mac and contribute to heating issues. Do some cleaning to slim things down:
- Delete unused apps, videos, photos, music, and files.
- Go through Documents and Downloads and trash unneeded stuff.
- Empty Trash and delete junk files with CleanMyMac.
- Remove software you don’t use via Uninstaller tools.
10. Check for malware and viruses
Malware infections can secretly tax your CPU and memory, making the fan go crazy. Scan your Mac for malware using software like Malwarebytes.
Also avoid downloading questionable files and software to prevent malware in the future.
Physically clean your Mac
Dust buildup within the Mac forces the fan to work extra hard. Regularly cleaning it can improve airflow and cooling efficiency.
Use compressed air
Use a can of compressed air to forcefully blow dust out of the Mac’s vents and heat sinks.
Hold the can upright and spray air in short bursts while aiming at the vents. Do this from different angles to remove all dust.
Open up the Mac (cautiously)
For older MacBooks and iMacs, you can open up the case to directly clean the fan and internal components. See Apple’s service manuals for your model.
Use a microfiber cloth to wipe dust off the fan blades, heat sinks, thermal sensors, and logic board. Be very careful not to detach any cables.
Replace worn-out fan
If your Mac’s fan is defective or worn out, it may spin loudly and constantly. Replacing an older fan can restore normal operation and noise levels.
You can buy replacement fans online and install them yourself or take your Mac to an Apple store or repair shop for a fan replacement.
Improve airflow and cooling
Optimizing airflow and heat dissipation keeps your Mac running cool, preventing the fan from going into overdrive.
Elevate your Mac
Using a stand or lift raises your MacBook or iMac for better airflow from below. Improved circulation prevents hot air pockets.
Laptop stands and cooling pads have built-in fans to actively move air and dissipate heat.
Remove case accessories
Cases, covers, skins, sleeves, and shells trap heat around the chassis, increasing internal temps. Remove any accessories that enclose the bottom or vents.
Adjust the workspace layout
Ensure at least 6 inches of clearance around your Mac for ventilation. Move it away from enclosed spaces, heat sources, and soft surfaces that can block airflow.
Also avoid using your Mac in warm environments which reduce the cooling efficiency.
Add an external cooling pad or stand
Cooling pads and stands with built-in fans can create supplemental airflow to force out hot air and draw in cool air.
Active cooling pads connect via USB and power an extra set of fans. Passive stands simply angle your MacBook for proper ventilation.
Use a laptop cooling app
Apps like Macs Fan Control let you monitor temperatures and manually control fan speeds.
Set the fans to spin faster to blow out hot air before the system gets too hot. This prevents the constant revving up and down of fans.
Avoid blocking ventilation
Ensure you are not blocking the air intake and exhaust vents that cool your Mac. This forces the fans to compensate and work overtime.
- Don’t place anything on top of your Mac, especially when powered on.
- Keep the vents clear of dust, bedding, carpets, or tablecloths.
- Don’t cram your Mac in an enclosed space like a bag when in use.
Give your Mac plenty of open space around the edges for ventilation. Keep the back side vents at least 6 inches from walls or other obstructions.
Manage CPU and GPU usage
Excess CPU and GPU usage results in more heat generation and fan activity. Keeping their usage in check prevents overheating.
Limit FPS in games
Lowering the game frame rates and video settings limits GPU usage, graphics heat production, and fan speed.
Cap the in-game FPS to 60-75 instead of maxing it out. Lower resolution, textures, shadows, and effects.
Pause uploads and downloads
File transfers over WiFi, cellular, or Ethernet can utilize a lot of bandwidth, CPU, and RAM.
Pause any ongoing iCloud syncing, app downloads, software updates, torrents, and large file transfers. Resume when you don’t need peak performance.
Avoid video calls and conferences
Processor-intensive apps like FaceTime, Skype, Zoom, Webex, and Microsoft Teams can heat up your Mac quickly.
Avoid video calls or limit call length when you notice your Mac getting hot. Close these apps when not on a video call.
Use Safari over Chrome
Google Chrome uses significantly more resources than Safari and other browsers. Use Safari or Firefox to limit CPU and GPU usage.
Safari also has native optimization and integration with macOS, giving better battery life and lower overhead.
Freeze CPU-intensive plugins
Plugins for audio, graphics, and development software can hog processing resources. Freeze them when not needed.
For example, freeze CPU-intensive tracks in your project, or effects in Photoshop.
Check Activity Monitor
Activity Monitor allows you to see which apps and processes are using up your CPU, memory, energy, disk, and network resources.
To open it:
- Click the Spotlight icon in the top menu bar.
- Type Activity Monitor and press Enter.
Click the CPU tab to see the apps using the most CPU. Look for anything taking up high percentages while running in the background.
Quit or force quit these processes to give your Mac a break and allow the fans to slow down.
Reset SMC and PRAM/NVRAM
Reseting the System Management Controller (SMC) and Parameter RAM (PRAM) can help your Mac run more efficiently and reduces fan spinning.
How to reset SMC
The SMC controls thermal management and fan speeds. Resetting it may stop fans from constantly spinning at high speeds.
To reset SMC:
- Fully shut down your Mac
- For MacBooks, press Shift + Control + Option + Power button for 10 seconds
- For iMacs and Mac Pros, unplug power cable for 15 seconds
- Reconnect power and restart Mac
How to reset PRAM/NVRAM
PRAM stores hardware settings and can get corrupted over time. Resetting PRAM may help with fan and temperature regulation issues.
To reset PRAM:
- Restart your Mac and immediately press Command + Option + P + R
- Hold keys down until you hear the startup chime a second time
- Release keys and let Mac restart normally
Conclusion
Constantly spinning and loud fans are annoying, but thankfully you can take steps to control fan speed. The key is reducing CPU and GPU usage and heat generation.
Start by closing intensive apps, increasing airflow, and disabling unnecessary settings. Cleaning out dust and updating software also helps your Mac run cooler and quieter.
With some troubleshooting and adjustments, you can stop your Mac’s fans from constantly running at high speeds.