Pi cooling fan results


#1

With a couple of summer heat waves, I’ve been getting the “anomaly” of high CPU temp on the stats page lately. My Pi is in an attic closet and I’d already pulled the top of the case off with minimal results. So into the scrap box (it’s really a room) and found a 1" 12v fan off of a disk “slider” and a 5v wall wart. Queue the hole saw, soldering iron some heat shrink and a few drops of super glue and about 5 minutes and there’s now a fan in the attached lid to the Pi case.

Results are rather astonishing over about 2 minutes of on time:
image

Just thought I’d throw it out there for anyone with the same high temperature situation…


#2

That’s a very good result.
Are you using heatsinks? and what is the ambient temp?

I too use 12V fans on 5V (silent and the bearings last forever).
Rather than using a wall-wart, I pull power from pins 4 (5V) + 6 (gnd) of the GPIO header.


#3

I’ve seen a couple of interesting videos on the topic, this is one of them:


#4

I use small old cpu (486) fans, powered 12v from the pc in both RPi’s, one of which has also heatsinks. both RPi’s show temp < 50°C. also being in an attic.

pi@piaware:~ $ /opt/vc/bin/vcgencmd measure_temp
temp=47.2'C

#5

I had to put a fan, with a heatsink on some of mine. They were just getting too hot in the attic and throttling the CPU. You can get a fan for about $10-15. and it connects directly to a couple of GPIO pins.

The Heatsink doesn’t have to be that good, especially with a fan.
The heatsink compound or tape is much more important as it does most of the heat transfer.


#6

Yes on the heatsinks. That was the first thing I tried. I can’t say they made more than a couple of degrees © difference before I put the fan on. They’re the cheap ones that come in some of the starter kits. I actually scavenged them from a dead pi I had.
I ran them off of a separate power supply to not pull any extra than I have to from the pi’s supply.
It’s been getting over 90 degrees in the afternoon in area where my receiver lives.


#7

Not sure if it’s the same fan you are referring to, but they are available for 99 cents on eBay.

I just received a case and fan. It was $1.99 shipped.


#8

What fan is needed to keep this 1960s electronics cool? :smiley:

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#9

There is an official raspberry pi POE HAT + fan coming out soon.
No word on final pricing or release date.
The rumor is end of summer and cost around 15.


#10

The German rasppishop.de lists it as available on 08.08.18, ie tommorow, for a price of 19.99 EURO + pp.

Not sure if that will really happen, and availability might be different from market to market.

The fan looks to be pretty small, and adding a hat will not be really beneficial for the airflow.


#11

I used this for my RPi. Dropped my temps from 57C to 42C. Silent fan too.


#12

@david.baker,
I ordered these when I bought my RPI3b+'s in March.
The expected delivery date back then was April 11.
They were $20 on element14.com


#13

EXTREME COOLING …BUT NOT FOR Pi

Liquid nitrogen has an extraordinarily low boiling point of -196 degrees Celsius = -321 degrees Fahrenheit = 77 degrees Kelvin

Setting up PC for liquid nitrogen cooling

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Liquid Nitrogen Overclock 5.1 GHz


#14

How is this for a comparison,
An RPI1 has about the same computing power as a 1988 Cray supercomputer

An RPI3B+ has 4 cores and runs at twice the Mhz.


#15

The close spacing of the PoE HAT will increase the air velocity and will probably improve the cooling.


#16

I guess it will also depend on the type of enclosure. I assumed it woul direct airflow directly over the CPU, or is it more likely to suck the air out like a case fan?

Still wondering if it will improve overall cooling or just offsetting the effect of the hat, remembering the pictures people posted here about PoE Pis in small boxes on hot roofs…