Uploaded July 2019 | Updated September 2026, 3 weeks ago
I've recently purchased some Raspberry Pi 4 and wanted to use them in some projects. It runs hotter than my old Raspberry Pi 3. I spent some time evaluating the temperature under load and trying out various fans to see how much fan RPM is necessary to produce a noticeable reduction in CPU temperature. I ended up settling on a 4-pin fan from delta electronics that easily allows fan speed to be controller from the raspberry pi and RPM to be read back. This fan is only 7mm thick making it ideal for fitting inside a relatively tight raspberry pi case. The fan part number is ASB0305HP-00CP4 and I bought it for just under ten bucks from digikey (digikey part number 603-2070-ND). Being able to control the fan speed easily from the pi is a great feature, as most of the time you don't need a noisy screaming fan at 9500 rpm. Something as low as just 1500 rpm may do. That's if you think you need a fan at all. For more electronics stuff, see smbaker.com
I've recently purchased some Raspberry Pi 4 and wanted to use them in some projects. It runs hotter than my old Raspberry Pi 3. I spent some time evaluating the temperature under load and trying out various fans to see how much fan RPM is necessary to produce a noticeable reduction in CPU temperature. I ended up settling on a 4-pin fan from delta electronics that easily allows fan speed to be controller from the raspberry pi and RPM to be read back. This fan is only 7mm thick making it ideal for fitting inside a relatively tight raspberry pi case. The fan part number is ASB0305HP-00CP4 and I bought it for just under ten bucks from digikey (digikey part number 603-2070-ND). Being able to control the fan speed easily from the pi is a great feature, as most of the time you don't need a noisy screaming fan at 9500 rpm. Something as low as just 1500 rpm may do. That's if you think you need a fan at all. For more electronics stuff, see smbaker.com










