I keep my iMac20,1 fan at maximum because the temperature goes from 50º C to 74º C all the time. I would like to know how to lower that temperature, so my iMac lasts.
I'm willing to put an ugly suction reverse blower if that is the only solution, but I don't know how.
Please help.
iMac 27″, macOS 14.5
Any anti-virus apps or so-called "cleaning" software will run up temps. So can leavign some web pages open inteh background, especially with Chrome.
Many iMac heat issues are workstation-related.
—One really unexpected cause I encountered here and verified on my 2017 iMac 5K is tipping the display too far forward. A user posted overheating problems and, in working with him, I found he had the iMac above eye level with the display tipped fully forward. Prior to 2012 that would not be a problem as the exhaust vent was above the stand. However, in later models, the exhaust vent is below and behind the top of the stand:
I did not believe that was an issue until I tried that with my iMac 27. Tipping the case forward reduces the gap between vent and stand. When I tested mine in that position with a remote-sensing thermometer sensor and temperature software, it was apparent the stand could restrict the exhaust vent enough to raise temps. The user changed the iMac's position to eliminate the tipping, and reported back the temps were lower.
—Another workplace cause is stacking stuff under the display. A user asked here why his iMac was overheating and posted this image:
When I worked in law enforcement, we called that a "clue." Cool air intakes are on the bottom edge of the case and must be unobstructed. The user removed the papers and the temps dropped.
Any anti-virus apps or so-called "cleaning" software will run up temps. So can leavign some web pages open inteh background, especially with Chrome.
Many iMac heat issues are workstation-related.
—One really unexpected cause I encountered here and verified on my 2017 iMac 5K is tipping the display too far forward. A user posted overheating problems and, in working with him, I found he had the iMac above eye level with the display tipped fully forward. Prior to 2012 that would not be a problem as the exhaust vent was above the stand. However, in later models, the exhaust vent is below and behind the top of the stand:
I did not believe that was an issue until I tried that with my iMac 27. Tipping the case forward reduces the gap between vent and stand. When I tested mine in that position with a remote-sensing thermometer sensor and temperature software, it was apparent the stand could restrict the exhaust vent enough to raise temps. The user changed the iMac's position to eliminate the tipping, and reported back the temps were lower.
—Another workplace cause is stacking stuff under the display. A user asked here why his iMac was overheating and posted this image:
When I worked in law enforcement, we called that a "clue." Cool air intakes are on the bottom edge of the case and must be unobstructed. The user removed the papers and the temps dropped.
Use Activity Monitor to find out what Programs or CPU Activities are causing the iMac to run warn?
see > Activity Monitor User Guide for Mac - Apple Support
and > View CPU activity in Activity Monitor on Mac - Apple Palaikymas (LT)
50º C to 60º C is only warm for an iMac. 80º to 90º C is hot for an iMac.
If you are watching videos, playing games or using Pro App's?
Then try running the fan at around 2000 or 3000 rpm to see if the temperature will hold at or just below 50º C.
Have you blown the dust out lately?
Also, on my 2019 iMac I've found the crazy deal that a great amount of heat comes from the Screen, & putting it in Night Shift , Dak Mode, or filling the screen with black will lower CPU temp by 20-30° C. ???
Fan & temperature problem.
