Outdoor Raspberry Pi Project: Temperature Management Challenge

Projects General Guidance
1

Hello everyone,

Chris here, I'm a data scientist. I'm seeking help to gather ideas on how to solve a challenging issue: managing temperatures in an enclosed environment housing a Raspberry Pi and other components, as stated in the title.

I'm working on an outdoor camera trap project with a neural network loaded onto a Raspberry Pi 5 for the recognition of specific animal species.

I've already selected the various components and have reached a crucial stage regarding temperature management.

For research reasons beyond this discussion, alongside the Pi 5 there will be a small 50W audio amplifier, a motion sensor (Doppler), an LTE transmission module, a NoIR v2 camera, and—this is part of my question—another element I will mention shortly, along with the necessary relays and power supplies.

The power supply will be wired and provided by urban lighting, so photovoltaic panels won't be necessary.

Since there is no commercially available casing tailored for these components, a custom one will be created using any of the materials available for spools. There are no budget restrictions for the Pi or other components.

The issue at hand—a well-known problem—is the thermal management of the Pi: The installation site will be in an area with extremely cold winter temperatures, dropping to -15 or -20 degrees Celsius, below the operational threshold of the components typically used in such projects.

I would prefer to avoid using components rated for extreme temperatures (industrial-grade), as although it would be a logical and correct solution, it would also require applying that standard to all other components, which is not always easy to source.

It's a more challenging problem, but if anyone has ideas, managing and controlling the internal temperature of the casing would be more interesting.

One possible solution for extreme cold temperatures could be using a heating resistor (this is the element I mentioned earlier), controlled by the Raspberry Pi, which monitors the temperature using a sensor. But I'm asking for ideas from the forum, as I know there are members with experience in Pi projects. If this approach isn't ideal, I'd love to hear alternative suggestions.

Regarding the opposite extreme—high temperatures—I’ve seen solutions involving fans, but they were quickly dismissed by the community due to predictable outdoor issues, including biological factors like insects and pollen, and abiotic factors such as dew point, condensation, pin oxidation, etc., which would be introduced along with humid air.

Here is the video I'm referring to: https://www.youtube.com/watch?v=ccMmqs5n_o8

I’d prefer passive solutions for heat dissipation, possibly using silica gel packs that need periodic replacement to manage condensation, but I'm open to forum suggestions.

Data:

  1. The Pi 5 will be constantly running with the neural network loaded.
  2. It will be waiting for a signal from the Doppler sensor.
  3. Once the signal is received, the image capture sequence, classification, and subsequent decisions will commence—but this will only occur for a few events during the day. The vast majority of the time, only phases 1) and 2) will be active.

The heat generated by these functions also includes the heat from a 75-100W power supply that will collectively power the Pi and all other components, each according to its requirements.

An interesting idea proposed by a knowledgeable individual is using a Peltier cell—certainly a great concept.

What concerned me is that while it cools on one side, it heats on the other, and in an enclosed space, I feared it might result in a neutral thermal balance (though I’d be happy to be proven wrong, as it would solve the problem instantly).

Certainly, the thermal tolerance of the Pi, with its 80-85°C thresholds, provides some leeway, but in a sealed environment with limited volume, I worry that the temperature will inevitably rise over several hours, requiring a long time to dissipate through the walls.

I’ve been considering hybrid ideas: We have the constraint of a sealed casing to prevent the introduction of external air that could cause oxidation and other issues, but we also need thermal exchange, which the casing alone likely won’t guarantee.

For this reason, I was thinking about a hybrid "box within a box" system, meaning: An internally sealed box contained within another box that has openings to the outside.

The inner box would have condensation-absorbing salts and perforations allowing conductive metal components like copper or aluminum to exchange heat with the outer chamber, which would allow external air to circulate freely.

The conductive components passing through or corresponding to the perforations could be:

A) Copper tubes where air is forced through by a fan at the entrance and one at the exit (air isn’t the best heat dissipator, but fans could help optimize circulation).

B) Classic copper or aluminum heatsinks with fins or columns, fixed to the casing and with dissipative elements 'bathed' in the fresh air of the interspace.

C) A Peltier cell attached to a wall, directing the hot side outward, assuming its operating temperatures are compatible with the 3D-printed casing material.

For option A), the perforations would be standard circular holes with common gaskets, whereas for options B) and C), the hole would be polygonal with more complex sealing systems, both in terms of gaskets and securing screws to the walls.

Ultimately, everything depends on your experience and whether using one system over another is truly worthwhile.

What would you use to manage temperature for a durable outdoor project?

Thanks to everyone willing to help

2

Avoid relying solely on internal Pi-generated heat—it won’t suffice during inactive hours.
Peltier in heating mode—it’s inefficient and poorly suited for this application in cold environments unless externally optimized (more below).

3

Put your electronics inside a domestic fridge. Hack the thermostat so that it cycles between 20 and 30 deg C. Usually there's just a switch that turns the compressor on and off.
You'll also need a heating pad and controller for when the inside temperature drops below 15 deg C.

Or if you have unlimited money and electricity just build you own fridge using an array of Peltier coolers bolted to one side of an aluminium box. Again you'll need a heater for cold nights. Peltier coolers don't make any noise which may be useful for your particular application.

4

There are heaters & coolers for electronic enclosures. Here's some information from Hammond on sizing them. They also sell heaters. General Selection Considerations - Hammond Mfg.

What's the outside air temperature where this thing will be located? If it's not too bad, keeping it out of direct sunlight might be enough to limit the internal temp to under 85C. However, is that 85C the recommended ambient max for the Pi or the internal CPU temperature? Internal temp can be well above ambient.

5

The most cost effective parts would be Automotive. These have a typical temperature range for automotive semiconductor parts from -40 °C to 125 °C, depending on the specific grade of the component, such as AEC-Q100 Level 2 which is rated from -40 °C to 105 °C. These ranges ensure that the components can operate reliably in the harsh conditions often found in automotive environments. There are some components such as some MOSFETs rated at 175C so you need to check the data sheet.

6

Thanks guys.

@cedarlakeinstruments
thanks for the link, I took a look at the coolers but from what I've seen they rely on fan systems which in an enclosed environment (must be so, in order to avoid moisture and pests) would result in a severely dampened effect.
The 85 is a threshold temperature but not the (internal) maximum. Anyway this is a project which will be implemented on large scale 24/7, so I have to provide stable solutions avoiding overstressing the components

@gilshultz
Thank Gils, yeah the idea of structuring the ensemble directly by industrial components is not dismissed at all. Some components with industrial specs are hard to come by, that's why I was trying a 'corrected' solution but sure, every 'passive' solution with less components would be less prone to generate problems

7

It's in first post.

8

The RPi can freeze :upside_down_face:

Another thing that works well as a heat source is an incandescent light bulb.

9

I believe I said Automotive components, they will give you a much larger temperature range then commercial.

1 Like
10

Perhaps i should have specified that i was asking for a range? Clearly a cooler isn't needed at the lower end.

11

If you have looked for it you notice there's no operating °C range spec'd. Temperatures mentioned however from other sources are 65 and 80/85, and that the Pi throttle at the latter temperatures. That would be the ambient and internal you were asking for.