Summer is here


#1

Outside temperature: 90F / 32C
Non conditioned garage temperature at the level of receivers: 88F / 31C
Message from my two receives… see below.

Temperature

They where laying flat, I have lifted them in a vertical position, hopefully they’ll cool better.


#2

Hmm…I was trying to figure out how to get an outdoor antenna setup without having to place the pi outside. I saw this post and was surprised the OP said it hasn’t fried itself.

Does your garage have any airflow? Are you only feeding off of this device?


#3

The temperature inside will eventually be equal to the outside one, it’s thermodynamics. 32C outside will slowly become 32C inside (usually around 3PM).
The only way it cools down is when we open the house door (it’s attached) and cold air from the house mixes a little bit in there.

I could add a small fan to blow on the Pi’s, because they are still way hotter than the ambient, so that might help. One of them has heatsinks over all the chips and it shows.

As for the outside setup… that might work in colder places. But not where it can be very hot, especially not directly in the sun.
Example: My company installed some electronic equipment in Africa, outside, the same way that works outside in southern US (still hot). But, at the Equator, we ended up providing sun-shades over the metallic boxes containing the equipment, because we kept “loosing” electronic boards. The fans where not a good option due to sand that was clogging the filters.
In some places I even saw small A/C units next to electronics boxes, but that’s just asking for trouble.


#4

That’s the minimum anybody should do. These heatsinks cost 99 cents for the pair. My Pi is in the garage, and it had no heatsinks for the first year, it does now.

Granted that the temperature up here does not go as high as in other places, it does get hot in the summer. It’s 13 Celsius right now, the Pi is at 40 Celsius.


#5

edit: yeah i checked temperature is the same with default settings running typical feeder workload
[[[ you can reduce the clock if you are using a newer pi.

i got a brand new 3b+ and i just set the clockrate to 600Mhz

the dynamic frequency switching probably does not go well with the constant work of shoveling the USB packets and decoding them.
i don’t know if it helps but i also reduced the gpu freq as i’m not even using it.
you can google for the /boot/config.txt settings for the raspi you are using and adjust accordingly.

not recommended if you want do other stuff with the raspi as it of course gets quite a bit slower when actually doing stuff. ]]]


#6

I thought about that some time ago, but then I read this:

"I’m not sure anyone outside a lab has ever hit 85 (and I think that required a hot air gun blowing on the SoC). Someone has reported 80, in a closed unventilated case, running GPU and CPU full tilt (a very unlikely scenario) in ambient of I think 25.

Underclocking doesn’t really make any difference to core temperature.

Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Please direct all questions to the forum, I do not do support via PM."

YMMV


#7

The cores will adjust the frequency and voltage automatically with the load. Sure, there are multiple governors that can handle this better or worse, but essentially, lowering the maximum frequency won’t help.
“/etc/init.d/raspi-config” controls the on-demand governor during boot up.
Other option would be this:
https://wiki.debian.org/HowTo/CpuFrequencyScaling